Patents by Inventor Andreas Karl Roelofs
Andreas Karl Roelofs 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).
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Patent number: 8830734Abstract: Method and apparatus for writing data to a magnetic memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In accordance with various embodiments, a write current is applied through a selected magnetic memory cell to initiate magnetic precession of the selected cell to a desired magnetic state. A field assist current is concurrently flowed through an adjacent memory cell to generate a magnetic field that assists in the precession of the selected cell to the desired magnetic state.Type: GrantFiled: November 19, 2010Date of Patent: September 9, 2014Assignee: Seagate Technology LLCInventors: Andreas Karl Roelofs, Haiwen Xi
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Publication number: 20120127785Abstract: Method and apparatus for writing data to a magnetic memory cell, such as a spin-torque transfer random access memory (STRAM) memory cell. In accordance with various embodiments, a write current is applied through a selected magnetic memory cell to initiate magnetic precession of the selected cell to a desired magnetic state. A field assist current is concurrently flowed through an adjacent memory cell to generate a magnetic field that assists in the precession of the selected cell to the desired magnetic state.Type: ApplicationFiled: November 19, 2010Publication date: May 24, 2012Applicant: SEAGATE TECHNOLOGY LLCInventors: Andreas Karl Roelofs, Haiwen Xi
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Patent number: 8000215Abstract: The presently disclosed technology teaches an improved voltage pattern for conductive tips utilized as moveable top electrodes for writing data bits into ferroelectric media. A conductive tip is dragged in contact or near contact with a ferroelectric surface forming a moveable top electrode on a ferroelectric media disk. A metallic film is deposited onto a bottom-side of the ferroelectric media forming a conductive bottom electrode. Applying electrical voltage pulses between the conductive tip and the bottom electrode induces polarization switching of the ferroelectric media under the head. The improved voltage pattern incorporates positive and negative overshoot voltages to induce a polarization switch in the ferroelectric media and positive and negative drag voltages to expand a polarized region on the ferroelectric media. Potential benefits of the improved voltage pattern include reduced cross-track blooming and reduced along-track blooming resulting in a more uniform track width and bit series length.Type: GrantFiled: August 12, 2009Date of Patent: August 16, 2011Assignee: Seagate Technology LLCInventors: Andreas Karl Roelofs, Tong Zhao, Martin Gerard Forrester
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Patent number: 7903533Abstract: An apparatus includes a storage medium, and a transducer positioned adjacent to the storage medium, wherein the transducer includes a first electrode and a second electrode, with the width of the first electrode being less than the width of the second electrode. A method including: applying a first voltage to a transducer to write data to a storage medium, and applying a second voltage to the transducer to read data from the storage medium, wherein the magnitude of the first voltage is greater than the magnitude of the second voltage.Type: GrantFiled: April 23, 2007Date of Patent: March 8, 2011Assignee: Seagate Technology LLCInventors: Mark David Bedillion, Andreas Karl Roelofs, Earl Chrzaszcz Johns, Yongjun Zhao, Edward Stephen Skalko
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Publication number: 20110038246Abstract: The presently disclosed technology teaches an improved voltage pattern for conductive tips utilized as moveable top electrodes for writing data bits into ferroelectric media. A conductive tip is dragged in contact or near contact with a ferroelectric surface forming a moveable top electrode on a ferroelectric media disk. A metallic film is deposited onto a bottom-side of the ferroelectric media forming a conductive bottom electrode. Applying electrical voltage pulses between the conductive tip and the bottom electrode induces polarization switching of the ferroelectric media under the head. The improved voltage pattern incorporates positive and negative overshoot voltages to induce a polarization switch in the ferroelectric media and positive and negative drag voltages to expand a polarized region on the ferroelectric media. Potential benefits of the improved voltage pattern include reduced cross-track blooming and reduced along-track blooming resulting in a more uniform track width and bit series length.Type: ApplicationFiled: August 12, 2009Publication date: February 17, 2011Applicant: Seagate Technology, LLCInventors: Andreas Karl Roelofs, Tong Zhao, Martin Gerard Forrester
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Patent number: 7876661Abstract: An apparatus that provides for non-destructive readback of a ferroelectric material. The apparatus can include a ferroelectric layer with a scannable surface wherein the ferroelectric layer has a compensation charge adjacent the scannable surface. The apparatus also can include an electrode adjacent the scannable surface to sense the compensation charge. A related method is also disclosed.Type: GrantFiled: October 2, 2007Date of Patent: January 25, 2011Assignee: Seagate Technology LLCInventors: Tong Zhao, Martin G. Forrester, Florin Zavaliche, Dierk Guenter Bolten, Andreas Karl Roelofs
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Patent number: 7869335Abstract: An apparatus includes a first ferroelectric storage layer and a second ferroelectric storage layer adjacent the first ferroelectric storage layer. A coupling layer may be between the first ferroelectric storage layer and the second ferroelectric storage layer. The ferroelectric storage layers may be configured as a data storage medium for use in a data storage system. A related method is also disclosed.Type: GrantFiled: October 9, 2007Date of Patent: January 11, 2011Assignee: Seagate Technology LLCInventors: Markus Jan Peter Siegert, Andreas Karl Roelofs, Martin Gerard Forrester
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Patent number: 7813254Abstract: An apparatus comprises mechanically scanned ferroelectric data storage media. A scanning electrode contacts the scannable surface with a contact force. The ferroelectric data storage media generates a piezoelectric potential that is picked up by the electrode. The piezoelectric potential has a polarity that varies as a function of data polarity on the data storage media.Type: GrantFiled: February 8, 2007Date of Patent: October 12, 2010Assignee: Seagate Technology LLCInventors: Markus Jan Peter Siegert, Andreas Karl Roelofs, Martin Gerard Forrester
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Patent number: 7782741Abstract: Ferroelectric media includes a media surface that is scannable by a contact. The contact provides a read signal. A polarization pattern is written in first regions of the media surface. The polarization pattern represents position data. The first regions are selectively exposed to an energy source. The exposing provides an imprint to the polarization pattern that prevents subsequent erasure by the read signal.Type: GrantFiled: January 18, 2007Date of Patent: August 24, 2010Assignee: Seagate Technology LLCInventors: Andreas Karl Roelofs, Martin Gerard Forrester
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Publication number: 20090092805Abstract: An apparatus includes a ferroelectric layer and a polarization pattern configured in the ferroelectric layer to represent position data. The polarization pattern has a switchable polarization state domain and an unswitchable polarization state domain. A method includes providing a ferroelectric layer and establishing a polarization pattern in the ferroelectric layer to represent position data.Type: ApplicationFiled: October 3, 2007Publication date: April 9, 2009Applicant: Seagate Technology LLCInventors: Tong Zhao, Andreas Karl Roelofs, Florin Zavaliche, Philip George Pitcher
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Publication number: 20090092032Abstract: An apparatus includes a first ferroelectric storage layer and a second ferroelectric storage layer adjacent the first ferroelectric storage layer. A coupling layer may be between the first ferroelectric storage layer and the second ferroelectric storage layer. The ferroelectric storage layers may be configured as a data storage medium for use in a data storage system. A related method is also disclosed.Type: ApplicationFiled: October 9, 2007Publication date: April 9, 2009Applicant: Seagate Technology LLCInventors: Markus Jan Peter Siegert, Andreas Karl Roelofs, Martin Gerard Forrester
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Publication number: 20090086613Abstract: An apparatus that provides for non-destructive readback of a ferroelectric material. The apparatus can include a ferroelectric layer with a scannable surface wherein the ferroelectric layer has a compensation charge adjacent the scannable surface. The apparatus also can include an electrode adjacent the scannable surface to sense the compensation charge. A related method is also disclosed.Type: ApplicationFiled: October 2, 2007Publication date: April 2, 2009Applicant: Seagate Technology LLCInventors: Tong Zhao, Martin G. Forrester, Florin Zavaliche, Dierk Guenter Bolten, Andreas Karl Roelofs
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Patent number: 7447140Abstract: An apparatus comprises a ferroelectric storage medium, and a transducer for reading data from the ferroelectric storage medium and for writing data to the ferroelectric storage medium, wherein the transducer includes a substrate and a probe coupled to the substrate, wherein the probe includes a conductive element and a bilayer structure causing the probe to bend toward the ferroelectric storage medium.Type: GrantFiled: July 30, 2004Date of Patent: November 4, 2008Assignee: Seagate Technology LLCInventors: Mark Ian Lutwyche, Earl Chrzaszcz Johns, Martin Gerard Forrester, Mark David Bedillion, Andreas Karl Roelofs, Joachim Walter Ahner, Robert Earl Rottmayer, Andre Y L Liem, Edward S. Skalko, Xueshi Yang
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Publication number: 20080259779Abstract: An apparatus includes a storage medium, and a transducer positioned adjacent to the storage medium, wherein the transducer includes a first electrode and a second electrode, with the width of the first electrode being less than the width of the second electrode. A method including: applying a first voltage to a transducer to write data to a storage medium, and applying a second voltage to the transducer to read data from the storage medium, wherein the magnitude of the first voltage is greater than the magnitude of the second voltage.Type: ApplicationFiled: April 23, 2007Publication date: October 23, 2008Applicant: Seagate Technology LLCInventors: Mark David Bedillion, Andreas Karl Roelofs, Earl Chrzaszcz Johns, Yongjun Zhao, Edward Stephen Skalko
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Publication number: 20080192528Abstract: An apparatus comprises mechanically scanned ferroelectric data storage media. A scanning electrode contacts the scannable surface with a contact force. The ferroelectric data storage media generates a piezoelectric potential that is picked up by the electrode. The piezoelectric potential has a polarity that varies as a function of data polarity on the data storage media.Type: ApplicationFiled: February 8, 2007Publication date: August 14, 2008Applicant: Seagate Technology LLCInventors: Markus Jan Peter Siegert, Andreas Karl Roelofs, Martin Gerard Forrester
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Publication number: 20080175133Abstract: Ferroelectric media includes a media surface that is scannable by a contact. The contact provides a read signal. A polarization pattern is written in first regions of the media surface. The polarization pattern represents position data. The first regions are selectively exposed to an energy source. The exposing provides an imprint to the polarization pattern that prevents subsequent erasure by the read signal.Type: ApplicationFiled: January 18, 2007Publication date: July 24, 2008Applicant: Seagate Technology LLCInventors: Andreas Karl Roelofs, Martin Gerard Forrester