Dual-surface flexible magnetic tape
AssigneeInternational Business Machines Corporation
InventorRichard Lionel Bradshaw
Life of this patent
Estimating the term…
Abstract
A flexible magnetic-tape substrate is coated on both sides with an underlayer of relatively-low coercivity magnetic medium, which in turn is coated with a submicron layer of chromium dioxide in ultra small particles having a high coercivity. For longitudinal magnetic recording systems, magnetic layers with a coercivity of at least 1,500 Oe with underlayers having a coercivity between 25 and 500 Oe are used. For helical magnetic recording systems, magnetic layers with a coercivity of at least 2,000 Oe with underlayers having a coercivity between 25 and 800 Oe are used. These properties greatly reduce the effects of neighboring magnetic fields, thereby improving signal retention and virtually eliminating print-through and contact recording.
Claims26
A magnetic recording medium comprising:
- a support substrate;
- a first underlayer of magnetic material coated onto a first side of said support substrate;
- a second underlayer of magnetic material coated onto a second side of the support substrate;
- a first layer of magnetic material coated onto said first underlayer;
- a second layer of magnetic material coated onto said second underlayer;
- and
- wherein said first and second underlayers have a coercivity smaller than about 800 Oe, and said first and second layers of magnetic material have a coercivity greater than about 1,500 Oe.
A magnetic recording cartridge comprising:
- (a) a housing;
- (b) a dual-surface flexible magnetic tape contained within the housing, said tape including:
- a support substrate;
- a first underlayer of magnetic material coated onto a first side of said support substrate;
- a second underlayer of magnetic material coated onto a second side of the support substrate;
- a first layer of magnetic material coated onto said first underlayer;
- and
- a second layer of magnetic material coated onto said second underlayer;
- and
- (c) means for enabling read/write operations on said tape;
- wherein said first and second underlayers have a coercivity smaller than about 800 Oe, and said first and second layers of magnetic material have a coercivity greater than about 1,500 Oe.
Dependencies are inferred from the claim text.