Patents by Inventor Eric Rolf Christensen

Eric Rolf Christensen 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: 8767326
    Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Upon determining head amplitude is below a threshold value, the MR bias is adjusted for increasing the head amplitude and extending the useful life span of the tape drive.
    Type: Grant
    Filed: August 28, 2012
    Date of Patent: July 1, 2014
    Assignee: Industrial Business Machines Corporation
    Inventors: Said Abdullah Ahmad, Josephine Faith Bayang, Eric Rolf Christensen, Ernest Stewart Gale
  • Publication number: 20140063638
    Abstract: Magnetoresistive (MR) bias is dynamically controlled in a tape drive using a processor device. Upon determining head amplitude is below a threshold value, the MR bias is adjusted for increasing the head amplitude and extending the useful life span of the tape drive.
    Type: Application
    Filed: August 28, 2012
    Publication date: March 6, 2014
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Said Abdullah AHMAD, Josephine Faith BAYANG, Eric Rolf CHRISTENSEN, Ernest Stewart GALE
  • Patent number: 8625226
    Abstract: A method for selecting which tap coefficients of a programmable finite-impulse-response (FIR) equalizer to fix is disclosed. In one embodiment, such a method includes performing an initial calibration to determine an initial value for each tap coefficient of a FIR equalizer. These initial values may be used to produce a first waveform. The method then performs an operation on the first waveform to produce a second waveform comprising multiple lobes. The second waveform is then analyzed to determine one or more lobes of the second waveform that have the largest area. The method then fixes coefficients of one or more taps that are closest to the lobe or lobes having the largest area. A corresponding apparatus and computer program product are also disclosed.
    Type: Grant
    Filed: November 23, 2011
    Date of Patent: January 7, 2014
    Assignee: International Business Machines Corporation
    Inventors: Eric Rolf Christensen, Ernest Stewart Gale, Robert Allen Hutchins, Sedat Oelcer
  • Patent number: 8605380
    Abstract: A method for selecting which tap coefficients of a programmable finite-impulse-response (FIR) equalizer to fix includes performing an initial calibration to determine an initial value for each tap coefficient of a FIR equalizer. Using these initial values, a “total” FIR equalizer is determined which sets the tap coefficients to their initial values. The method further determines multiple sets of tap coefficients that may potentially be fixed in the FIR equalizer. For each set of tap coefficients that may potentially be fixed, the method determines a “fixed” FIR equalizer that sets the tap coefficients in the set to their initial values and other tap coefficients to zero. The method then determines a phase-difference energy between the “total” FIR equalizer and the “fixed” FIR equalizer for each set of tap coefficients that may potentially be fixed. The set of tap coefficients associated with the lowest phase-difference energy are then fixed.
    Type: Grant
    Filed: July 17, 2012
    Date of Patent: December 10, 2013
    Assignee: International Business Machines Corporation
    Inventors: Eric Rolf Christensen, Ernest Stewart Gale, Robert Allen Hutchins, Sedat Oelcer
  • Patent number: 8132050
    Abstract: Provided are a method, system, and article of manufacture for providing removable storage management services using removable storage error information. Read/write error information is obtained for at least one removable storage by interfacing with the removable storage manager. The obtained read/write error information for the at least one removable storage is processed to determine read/write error rates for the at least one removable storage. A determination is made as to whether the determined read/write error rates for the at least one removable storage exceed at least one read/write error threshold. At least one message is sent to the removable storage manager to replace the at least one removable storage having read/write error rates that exceed the at least one read/write error threshold.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: March 6, 2012
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Patent number: 8111473
    Abstract: A method of evaluating the performance of a magnetic recording system, comprising measuring a first set of finite impulse response filter tap values at time t1, measuring a second set of finite impulse response filter tap values are measured at time t2, where time t2 is subsequent to time t1, and calculating an actual loss parameter using the first set of tap values and the second set of tap values. The method then compares the actual loss parameter with a total effective loss threshold.
    Type: Grant
    Filed: August 28, 2009
    Date of Patent: February 7, 2012
    Assignee: International Business Machines Corporation
    Inventors: Eric Rolf Christensen, W. Stanley Czarnecki
  • Publication number: 20110119167
    Abstract: Provided are a method, system, and article of manufacture for providing removable storage management services using removable storage error information. Read/write error information is obtained for at least one removable storage by interfacing with the removable storage manager. The obtained read/write error information for the at least one removable storage is processed to determine read/write error rates for the at least one removable storage. A determination is made as to whether the determined read/write error rates for the at least one removable storage exceed at least one read/write error threshold. At least one message is sent to the removable storage manager to replace the at least one removable storage having read/write error rates that exceed the at least one read/write error threshold.
    Type: Application
    Filed: January 27, 2011
    Publication date: May 19, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Patent number: 7913117
    Abstract: Provided are a method, system, and article of manufacture for providing removable storage management services using removable storage error information. Read/write error information is obtained for at least one removable storage by interfacing with the removable storage manager. The obtained read/write error information for the at least one removable storage is processed to determine read/write error rates for the at least one removable storage. A determination is made as to whether the determined read/write error rates for the at least one removable storage exceed at least one read/write error threshold. At least one message is sent to the removable storage manager to replace the at least one removable storage having read/write error rates that exceed the at least one read/write error threshold.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: March 22, 2011
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Publication number: 20110051274
    Abstract: A method of evaluating the performance of a magnetic recording system, comprising measuring a first set of finite impulse response filter tap values at time t1, measuring a second set of finite impulse response filter tap values are measured at time t2, where time t2 is subsequent to time t1, and calculating an actual loss parameter using the first set of tap values and the second set of tap values. The method then compares the actual loss parameter with a total effective loss threshold.
    Type: Application
    Filed: August 28, 2009
    Publication date: March 3, 2011
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: ERIC ROLF CHRISTENSEN, W. STANLEY CZARNECKI
  • Patent number: 7870427
    Abstract: Provided are a method, system, and article of manufacture for accessing removable storage management services to obtain replacement instructions indicating whether to replace removable storage. Replacement information indicating whether to replace at least one of a plurality of managed removable storages is obtained by interfacing with a service computer over a network. Read/write error information for the at least one removable storage is gathered and transmitted to the service computer. Replacement instructions indicating whether to replace the at least one removable storage are received from the service computer.
    Type: Grant
    Filed: August 10, 2007
    Date of Patent: January 11, 2011
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Patent number: 7719782
    Abstract: Handling a magnetic tape cartridge comprises the steps of reading cartridge mount information from the cartridge memory; determining from the cartridge mount information whether the present mount is the first mount of the magnetic tape cartridge; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge, e.g., the fast forward is to end of tape (EOT) and the rewind is to beginning of tape (BOT). Alternatively, if the cartridge mount information indicates the present mount is the first mount of the magnetic tape cartridge; monitoring input/output with respect to the magnetic tape cartridge for write errors during the mount; determining whether the number of monitored write errors meets a predetermined threshold; and if so, fast forward and rewind the magnetic tape of the magnetic tape cartridge.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: May 18, 2010
    Assignee: International Business Machines Corporation
    Inventors: Allen Keith Bates, Shawn Owen Brume, Nhan Xuan Bui, Joel Hsien-Li Chen, Eric Rolf Christensen, Roger Javier Justo, Daniel James Winarski
  • Publication number: 20090044047
    Abstract: Provided are a method, system, and article of manufacture for accessing removable storage management services to obtain replacement instructions indicating whether to replace removable storage. Replacement information indicating whether to replace at least one of a plurality of managed removable storages is obtained by interfacing with a service computer over a network. Read/write error information for the at least one removable storage is gathered and transmitted to the service computer. Replacement instructions indicating whether to replace the at least one removable storage are received from the service computer.
    Type: Application
    Filed: August 10, 2007
    Publication date: February 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Publication number: 20090040650
    Abstract: Provided are a method, system, and article of manufacture for providing removable storage management services using removable storage error information. Read/write error information is obtained for at least one removable storage by interfacing with the removable storage manager. The obtained read/write error information for the at least one removable storage is processed to determine read/write error rates for the at least one removable storage. A determination is made as to whether the determined read/write error rates for the at least one removable storage exceed at least one read/write error threshold. At least one message is sent to the removable storage manager to replace the at least one removable storage having read/write error rates that exceed the at least one read/write error threshold.
    Type: Application
    Filed: August 10, 2007
    Publication date: February 12, 2009
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Allen Keith Bates, Eric Rolf Christensen, Shinobu Wada, Daniel James Winarski
  • Patent number: 7139142
    Abstract: A signal sampler digitally samples magnetic signals detected by read head(s) of a magnetic tape drive, and a signal quality system extracts from the digital samples of a format required signal of the magnetic signals, such as a data set separator pattern, an estimated amplitude of write equalization transitions of the format required signal; and compares the extracted estimated amplitude to acceptable amplitude.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: November 21, 2006
    Assignee: International Business Machines Corporation
    Inventors: David Berman, Eric Rolf Christensen
  • Patent number: 5920438
    Abstract: Disclosed are a programmable digital device and method for generating tracking threshold signals for qualification of input peak signals in response to programmed digital gain signals which control the rate at which the envelope of the qualified input peak signals is followed, and in response to a programmed digital attenuation signal which determines the proportion of the peak envelope at which to generate new tracking threshold signals. The programmable digital device and method also provide a programmed clamp signal to clamp the positive and negative threshold signals to not fall below the programmed values. An anti-hang capability is provided to allow the thresholds to drop after a programmed time period during which no signal is detected. In an alternative arrangement, the centerline of the envelope is followed and used as the threshold.
    Type: Grant
    Filed: July 15, 1998
    Date of Patent: July 6, 1999
    Assignee: International Business Machines Corporation
    Inventors: Eric Rolf Christensen, Robert Allen Hutchins, Ara Sarkis Patapoutian
  • Patent number: 5877644
    Abstract: Disclosed are a programmable digital device and method for generating tracking threshold signals for qualification of input peak signals in response to programmed digital gain signals which control the rate at which the envelope of the qualified input peak signals is followed, and in response to a programmed digital attenuation signal which determines the proportion of the peak envelope at which to generate new tracking threshold signals. The programmable digital device and method also provide a programmed clamp signal to clamp the positive and negative threshold signals to not fall below the programmed values. An anti-hang capability is provided to allow the thresholds to drop after a programmed time period during which no signal is detected. In an alternative arrangement, the centerline of the envelope is followed and used as the threshold.
    Type: Grant
    Filed: January 8, 1997
    Date of Patent: March 2, 1999
    Assignee: International Business Machines Corporation
    Inventors: Eric Rolf Christensen, Robert Allen Hutchins, Ara Sarkis Patapoutian