Magnetic recording apparatus and method of designing the same

Details Magnetic recording apparatus and method of designing the same Magnetic recording apparatus and method of designing the same

2005-05-17

2005-05-17

Hudspeth, David (Department: 2651)

Dynamic magnetic information storage or retrieval

General recording or reproducing

Thermomagnetic recording or transducers

C360S055000, C360S031000, C369S013010, C369S047100, C369S047150, C369S013090

Reexamination Certificate

active

06894857

ABSTRACT:
A method of designing a thermally-assisted magnetic recording apparatus having a magnetic recording medium, a heater and a magnetic head includes, determining a stable retention time tstfor recorded magnetization and a thermal-fluctuation stability coefficient βstcalculated from β(T)=KuV/kBT, where Kuis a magnetic anisotropy energy density, V is an activation volume, and kBis Boltzmann's constant, obtaining an equivalent degradation time tEQcalculated from tEQ=Σ(ΔtEQ), that sums values of ΔtEQwithin a period of time Δt for a time span during which the medium is substantially degraded, where ΔtEQ=exp(ln(Δt)−β−βst) and β is a thermal-fluctuation stability coefficient for a medium temperature T in Δt, and determining specifications of the medium, the heater and the magnetic head in a manner to meet the relationship of tEQ<tst.

REFERENCES:
patent: 6143436 (2000-11-01), Nakajima et al.
patent: 6307817 (2001-10-01), Tsuboi
patent: 6636460 (2003-10-01), Akiyama et al.
patent: 1 037 198 (2000-09-01), None
J. J.M. Ruigrok, et al., Journal of Applied Physics, vol. 87, No. 9, pps. 5398-5403, “Disk Recording Beyond 100 Gb/in.2: Hybrid Recording? (INVITED),” May 1, 2000.
S. H. Charap, et al., IEEE Transactions on Magnetics, vol. 33, No. 1, pps. 978-983, “Thermal Stability of Recorded Information at High Densities,” Jan. 1, 1997.
D. Weller, et al., IEEE Transactions on Magnetics, vol. 35, No. 6, pps. 4423-4439, “Thermal Effect Limits in Ultrahigh-Density Magnetic Reocording,” Nov. 1999.

Affiliated with

Also associated with

Rating

Magnetic recording apparatus and method of designing the same does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Magnetic recording apparatus and method of designing the same, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Magnetic recording apparatus and method of designing the same will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3418193