Source: http://www.google.com/patents/US20100002330?ie=ISO-8859-1
Timestamp: 2014-03-15 19:03:06
Document Index: 422439171

Matched Legal Cases: ['arts 800', 'art 800', 'art 802', 'art 806', 'arts 900', 'art 900', 'art 902', 'art 904', 'art 804', 'art 906', 'art 806']

Patent US20100002330 - Thermally assisted recording head control means for protrusion management - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign inAdvanced Patent SearchPatentsMethods and structures for improving fly height control for thin film write heads utilized in thermally assisted recording are disclosed. Methods include the use of the TAR near field light source to provide a preheating pulse to improve the transient response when moving from one fly height to another...http://www.google.com/patents/US20100002330?utm_source=gb-gplus-sharePatent US20100002330 - Thermally assisted recording head control means for protrusion managementAdvanced Patent SearchPublication numberUS20100002330 A1Publication typeApplicationApplication numberUS 12/217,379Publication dateJan 7, 2010Filing dateJul 3, 2008Priority dateJul 3, 2008Also published asUS7990647Publication number12217379, 217379, US 2010/0002330 A1, US 2010/002330 A1, US 20100002330 A1, US 20100002330A1, US 2010002330 A1, US 2010002330A1, US-A1-20100002330, US-A1-2010002330, US2010/0002330A1, US2010/002330A1, US20100002330 A1, US20100002330A1, US2010002330 A1, US2010002330A1InventorsJeffrey S. LilleOriginal AssigneeLille Jeffrey SExport CitationBiBTeX, EndNote, RefManReferenced by (12), Classifications (9), Legal Events (2) External Links: USPTO, USPTO Assignment, EspacenetThermally assisted recording head control means for protrusion managementUS 20100002330 A1Abstract Methods and structures for improving fly height control for thin film write heads utilized in thermally assisted recording are disclosed. Methods include the use of the TAR near field light source to provide a preheating pulse to improve the transient response when moving from one fly height to another prior to writing data. Methods and structures having an additional auxiliary optical heating source to avoid media overheating and replacement of embedded resistive heaters are also disclosed.
1. A method for writing data with a thin film magnetic head having a thermally assisted recording system and resistive heaters operable to heat said thin film magnetic head, comprising:
providing a first optical power level to said thermally assisted recording system between a first time t1 and a second time t2; providing a second optical power level to said thermally assisted recording system between said second time t2 and a third time t3, said first optical power level being greater than said second optical power level; and, writing data between said second time t2 and said third time t3. 2. The method as recited in claim 1, wherein said first optical power level is between 2 and ten times said second optical power level.
providing a first electrical power level to said resistive heaters for times less than said second time t2 and for times greater than said third time t3; and, providing a second electrical power level to said resistive heaters for times between said second time t2 and said third time t3. 4. The method as recited in claim 3, wherein said second electrical power level is less than said first electrical power level.
5. The method as recited in claim 4, wherein a fly height of said thin film magnetic head is reduced from a first fly height at said first time t1 to a second fly height at said second time t2.
6. The method as recited in claim 5, wherein said second fly height is adjusted between said second time t2 and said third time t3 by altering said second electrical power level.
7. The method as recited in claim 5, wherein said second fly height is adjusted between said second time t2 and said third time t3 by altering said second optical power level.
8. A method for writing data with a thin film magnetic head having a thermally assisted recording system and an auxiliary optical system operable to heat said thin film magnetic head, comprising:
providing a first optical power level to said auxiliary optical system between a first time t1 and a second time t2; providing a second optical power level to said auxiliary optical system between said second time t2 and a third time t3, said first optical power level being greater than said second optical power level; and, providing a third optical power level to said thermally assisted recording system between said second time t2 and said third time t3; and, writing data between said second time t2 and said third time t3. 9. The method as recited in claim 8, wherein said first optical power level is between 2 and ten times said third optical power level.
10. The method as recited in claim 8, wherein said first optical power level is between 2 and ten times said second optical power level.
providing a fourth optical power level to said auxiliary optical system for times less than said second time t2 and for times greater than said third time t3. 12. The method as recited in claim 11, wherein said fourth optical power level is greater than said second optical power level.
13. The method as recited in claim 8, wherein a fly height of said thin film magnetic head is reduced from a first fly height at said first time t1 to a second fly height at said second time t2.
14. The method as recited in claim 13, wherein said second fly height is adjusted between said second time t2 and said third time t3 by altering said second optical power level to said auxiliary optical system.
15. The method as recited in claim 13, wherein said second fly height is adjusted between said second time t2 and said third time t3 by altering said third optical power level to said thermally assisted recording system.
16. The method as recited in claim 13, wherein said second fly height is adjusted between said second time t2 and said third time t3 by altering said third optical power level to said thermally assisted recording system, and said second optical power level to said auxiliary optical system.
17. A thin film magnetic head structure comprising:
a near field optical source comprising a conductive metal film, an aperture fashioned in said conductive film; a first optical waveguide operable to illuminate said aperture, producing a near field light source suitable for thermally assisted recording; and, a second optical waveguide operable to illuminate a light absorption structure embedded within said thin film magnetic head, said light absorption structure suitable for converting light energy transmitted by said second optical waveguide to thermal energy, wherein control of said light energy is operable to alter protrusion of said thin film magnetic head structure at an air bearing surface of said thin film head structure. 18. The magnetic head as recited in claim 17, further comprising:
a first laser light source, optically coupled to said first optical waveguide; and, a second laser light source, optically coupled to said second optical waveguide. 19. The magnetic head as recited in claim 17, further comprising:
a laser light source; and, an optical switching device, optically coupled to said laser light source, said first optical waveguide, and said second optical waveguide, said optical switching device operable to deliver a first portion of light generated by said laser light source to said first optical waveguide, said optical switching device operable to deliver a second portion of light generated by said laser light source to said second optical waveguide. 20. The magnetic head as recited in claim 17, wherein said conductive metal film has a first surface approximately co-planar with said air bearing surface, said conductive metal film having a second surface approximately parallel with said first surface, said second surface opposing said first surface, said first optical waveguide making contact with at least a portion of said second surface.
21. The magnetic head as recited in claim 17, wherein said light absorption structure has a first surface approximately co-planar with said air bearing surface, said light absorption structure having a second surface opposing said first surface, said second optical waveguide making contact with at least a portion of said second surface. Description
SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for writing data with a thin film magnetic head having a thermally assisted recording system and resistive heaters operable to heat said thin film magnetic head. The method includes providing a first optical power level to the thermally assisted recording system between a first time t1 and a second time t2; providing a second optical power level to the thermally assisted recording system between the second time t2 and a third time t3, the first optical power level being greater than the second optical power level; and, writing data between the second time t2 and the third time t3.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1, 2, and 7 (Prior Art) have been discussed above.
FIG. 8 is a sequence of charts 800, 802, 804, and 806 illustrating write coil power, resistive TFC power, TAR optical power, and fly height as a function of time during a data write cycle, in accordance with the forgoing embodiments of the present invention. In the following discussion, TFC power is power delivered to resistive heaters (separate from the write coils) imbedded somewhere in the slider structure that contains the read/write thin film head. The reference �TFC� is associated with the embedded resistive heaters to maintain consistency with prior terminology, even though the thermal fly height control system of the present invention includes control of all energy sources including TAR optical power and coil power. TAR optical power is power delivered by the optical waveguide to the near field light source. Chart 800 shows average write coil power as data is being written between times t2 and t3. Resistive heater TFC power is shown in chart 802. Prior to the beginning of the data write cycle at t2, TFC power is at a nominal level of P3, which causes the head to fly at height H2 (see chart 806). During the write cycle between times t2 and t3, TFC power is reduced to power level P2 to compensate for increased power levels from the write coil and TAR optical power. In some cases, power level P2 can be close to zero, but it is desirable to have P2 at some minimum power level, so that the control system has some capability to trim the fly height H1 during the data write cycle between t2 and t3. The trimming may be necessary to compensate for changes in atmospheric pressure or ambient temperature. Power level P2 can also be varied as a function of the average write coil power, which of course may change depending on the profile of the data being written in a particular sector. This feature of the present invention is an improvement over the process shown in FIG. 7 (Prior Art), wherein the TFC power is turned off during the data write cycle, and the fly height H1 is determined solely by the coil power. The trimming may also be accomplished by adjusting the TAR optical power around the value OP1, but this may not as desirable due to the impact on media surface heating and the TAR process itself. Subsequent to the write cycle (times >t3), TFC power is returned to a power level of P3.
FIG. 9 is a sequence of charts 900, 902, 904, and 906 illustrating write coil power, resistive TFC power, TAR optical power, and auxiliary optical power as a function of time during a data write cycle, in accordance with the embodiments of FIGS. 3 c, 3 d, 4 b, 5 b, and 6 of the present invention. Chart 900 illustrates the application of average write coil power during the write cycle between time t2 and t3. Chart 902 illustrates the resistive TFC heater power levels. Prior to the beginning of the data write cycle at t2, TFC power is at a nominal level of P4. During the write cycle between times t2 and t3, TFC power is reduced to power level P2 to compensate for increased power levels from the write coil and TAR optical power. In some cases, power level P2 can be close to zero, but it is desirable to have P2 at some minimum power level, so that the control system has some capability to trim the fly height during the data write cycle between t2 and t3. Power level P2 can also be varied as a function of the average write coil power, which of course may change depending on the profile of the data being written in a particular sector. Subsequent to the write cycle (times >t3), TFC power is returned to a power level of P4. Chart 904 illustrates the TAR optical power. In this embodiment of the present invention, the TAR waveguide and near field source are not used to produce the preheat pulse shown in chart 804 of FIG. 8. The TAR power is only used to aid in writing data, being turned on at a power level of OP1 between times t2 and t3. This avoids any media overheating, or accidental erasure of data when media surface temperatures reach the paramagnetic limit in zones outside the intended sector. Chart 906 illustrates the auxiliary optical system power levels. Prior to time t1, a minimum power level OP3 is provided. This power level may be used to supplement TFC power if desired to aid in fly height fine tuning, or may optionally be set to zero if fly height control is to be maintained solely with TFC power. Between times t1 and t2, a preheat pulse is applied to a power level OP2, as was done previously in FIG. 8. During the write cycle between t2 and t3, the auxiliary optical power is turned off, as the fly height is trimmed with resistive heating TFC power combined with TAR optical power and write coil power. In this case, TFC power is utilized to fine tune fly height. Optionally, the auxiliary optical power may also be utilized to trim fly height for faster response changes if desired. Although a separate chart illustrating fly height as a function of time is not shown in FIG. 9, chart 806 can be utilized to obtain the same information.
Referenced byCiting PatentFiling datePublication dateApplicantTitleUS8300345 *Dec 4, 2009Oct 30, 2012Doug Carson & Associates, Inc.Variable track width recording compensationUS8351151Nov 2, 2010Jan 8, 2013Hitachi Global Storage Technologies Netherlands B.V.Thermally assisted magnetic write head employing a near field transducer (NFT) having a diffusion barrier layer between the near field transducer and a magnetic lipUS8369189Apr 14, 2011Feb 5, 2013Headway Technologies, Inc.Heat assisted narrow pole design with trailing shieldUS8406093 *Oct 13, 2010Mar 26, 2013Hitachi, Ltd.Thermal-assisted-magnetic-recording head having a high refractive index core and multiple thin film cores, and magnetic recording system using the thermal-assisted-magnetic-recording headUS8472286 *Dec 31, 2008Jun 25, 2013HGST Netherlands B.V.Near field transducer having main body and wings extending therefrom and only electrically coupled therebyUS8576509 *Aug 24, 2011Nov 5, 2013Western Digital Technologies, Inc.Disk drive configuring dual fly height actuators during write operationUS8593915 *Aug 1, 2011Nov 26, 2013Headway Technologies, Inc.Thermally-assisted magnetic recording head capable of reducing the transient protrusion of an antennaUS20100142087 *Dec 4, 2009Jun 10, 2010Doug Carson & Associates, Inc.Variable Track Width Recording CompensationUS20100165499 *Dec 31, 2008Jul 1, 2010Barry Cushing StipeThermally assisted recording head having an electrically isolated magnetic layer and a near field transducerUS20110090770 *Oct 13, 2010Apr 21, 2011Hitachi, Ltd.Thermal-assisted-magnetic-recording head and magnetic recording system using the thermal-assisted-magnetic-recoring headUS20110292773 *Aug 1, 2011Dec 1, 2011Headway Technologies, Inc.Power control of TAMR element during read/write transitionUS20130294207 *Jul 1, 2013Nov 7, 2013Seagate Technology LlcLight Source Power Control for Heat Assisted Magnetic Recording (HAMR)* Cited by examinerClassifications U.S. Classification360/59, G9B/5.026International ClassificationG11B5/02Cooperative ClassificationG11B5/6064, G11B5/314, G11B2005/001, G11B2005/0021European ClassificationG11B5/60D1J, G11B5/31D8A2Legal EventsDateCodeEventDescriptionOct 25, 2012ASAssignmentEffective date: 20120723Free format text: CHANGE OF NAME;ASSIGNOR:HGST, NETHERLANDS B.V.;REEL/FRAME:029341/0777Owner name: HGST, NETHERLANDS B.V., NETHERLANDSFree format text: CHANGE OF NAME;ASSIGNOR:HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.;REEL/FRAME:029341/0777Owner name: HGST NETHERLANDS B.V., NETHERLANDSAug 4, 2008ASAssignmentOwner name: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:LILLE, JEFFREY S.;REEL/FRAME:021352/0330Effective date: 20080627RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google