Method and apparatus for degaussing magnetic storage media

Electricity: electrical systems and devices – Control circuits for electromagnetic devices – Systems for magnetizing – demagnetizing – or controlling the...

Patent

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

335284, H01F 1300

Patent

active

045517827

ABSTRACT:
A method for degaussing a magnetic storage medium, such as a reel of magnetic tape, is disclosed. In the disclosed method, the reel of magnetic tape is simultaneously rotated on its axis and subjected to an applied transverse magnetic field substantially in the plane of the reel. The transverse magnetic field is applied first in one direction and then in the opposite direction. An axial magnetic field, substantially parallel to the axis of the reel, is then applied, first in one direction and then in the opposite direction. In the preferred embodiment, the step of applying an axial magnetic field includes applying axial magnetic fields in alternating directions at successively decreasing amplitudes. In the disclosed apparatus, the transverse magnetic field is obtained using a lateral coil which passes over and under the reel and covers about half the reel. The axial magnetic field is obtained using a ring-shaped coil surrounding the periphery of the reel. The sequence and characteristics of the applied magnetic fields as disclosed, are useful in obtaining a magnetic storage medium that is completely erased and leaves no significant amount of noise.

REFERENCES:
patent: 245275 (1881-08-01), Caldwell et al.
patent: 733637 (1903-07-01), Forster
patent: 2240749 (1941-05-01), Beechlyn
patent: 2786970 (1957-03-01), Connoy
patent: 3023280 (1962-02-01), Tronslin et al.
patent: 3143689 (1964-08-01), Hall
patent: 3321586 (1967-05-01), Krones
patent: 3588623 (1971-06-01), Camras
patent: 3619729 (1971-11-01), Littwin
patent: 3647990 (1972-03-01), Eul, Jr. et al.
patent: 3651382 (1972-03-01), Trammell
patent: 3655924 (1972-04-01), Puskas
patent: 3723668 (1973-03-01), Ritchey, Jr.
patent: 3810230 (1974-05-01), Orlowski et al.
patent: 3938011 (1976-02-01), Littwin
patent: 3958273 (1976-05-01), Alexandrovich, Sr. et al.
patent: 4135219 (1979-01-01), Yoshizawa et al.
patent: 4157581 (1979-06-01), Keiichi et al.
patent: 4346426 (1982-08-01), Baumann et al.
patent: 4360854 (1982-11-01), Schergen et al.
patent: 4458178 (1984-07-01), Tenney et al.
patent: 4466027 (1984-08-01), Howell et al.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Method and apparatus for degaussing magnetic storage media does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Method and apparatus for degaussing magnetic storage media, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for degaussing magnetic storage media will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-298641

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.