Multiple-layer backcoating for magnetic tape
First Claim
1. A magnetic tape comprising a substrate having disposed on opposite sides thereof a magnetic-layered recording surface and a non-recording surface containing a servo tracking pattern, the non-recording surface including at least two layers containing inorganic particles, a first outer layer containing inorganic particles larger in size than inorganic particles contained in a second inner layer, wherein the servo tracking pattern includes depressions extending through the first outer layer to the second inner layer.
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Accused Products
Abstract
A magnetic tape comprises a substrate having on one side thereof a magnetic layer serving as a recording surface, and on the other side thereof at least two layers containing inorganic particles which serve as a non-recording surface, wherein said magnetic tape has a region on the side of the non-recording surface along the longitudinal direction of the tape in which a regular pattern for servo tracking having different optical properties from the other major region of the side of the non-recording surface is or can be formed. The layers on the non-recording surface are characterized in that the inorganic particles in the outermost layer are larger than the inorganic particles in the underlying layer(s).
132 Citations
14 Claims
- 1. A magnetic tape comprising a substrate having disposed on opposite sides thereof a magnetic-layered recording surface and a non-recording surface containing a servo tracking pattern, the non-recording surface including at least two layers containing inorganic particles, a first outer layer containing inorganic particles larger in size than inorganic particles contained in a second inner layer, wherein the servo tracking pattern includes depressions extending through the first outer layer to the second inner layer.
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9. A magnetic tape comprising a substrate having disposed on opposite sides thereof a recording surface, and a non-recording surface containing a regular pattern for servo tracking along a longitudinal direction of the tape which pattern has optical properties which differ from a non-patterned region of the non-recording surface, wherein the recording surface comprises a magnetic layer, and the non-recording surface comprises at least two layers containing inorganic particles, an inner layer containing particles sized smaller than particles contained in an outer layer, wherein the pattern includes depressions extending through the outer layer to the inner layer.
- 10. A magnetic tape comprising a substrate having on one side thereof a recording surface comprising a magnetic layer, and on the other side thereof a backcoat system having disposed along the longitudinal direction of the tape a regular pattern for servo tracking having optical properties different from a non-patterned region, the backcoat system including at least two layers comprising a first outer layer and a second inner layer containing carbon black particles, the first outer layer containing carbon black particles sized larger than carbon black particles contained in the second inner layer, wherein the pattern includes depressions extending through the first outer layer to the second inner layer.
- 13. A method of making a recording tape, comprising providing a substrate having disposed on one side thereof a magnetic layer serving as a recording surface and on the other side thereof a backcoating system comprising a first outer layer and a second inner layer, the first outer layer containing particles sized larger than particles contained in the second inner layer, and directing a beam of light at said backcoat layer thereby to form an optically detectable depression in said backcoat layer, the depression extending through the first outer layer to the second inner layer.
Specification