Patent ID: 7060378

Claim:
A magnetic digital recorder comprising at least a reproduction head and magnetic recording tape, wherein an MR head is used for the reproduction head, and the magnetic recording tape comprising a coating layer containing fine particles and organic compounds and having a surface A formed on one side of a polyester film, fine surface protrusions being formed at a density of 5×10 6 to 9×10 7 protrusions/mm 2 on surface A, the polyester film satisfying the following conditions: (1) the mean diameter of the fine surface protrusions is in the range of 20 to 100 nm, (2) the mean height of the fine surface protrusions is in the range of 10 to 30 nm, and (3) the degree of cohesion of the fine surface protrusions is less than 5%, wherein a ferromagnetic metal thin layer is formed on surface A.