Patent ID: 6607156
Filing Date: 2003-08-19
Classification: G11B

Abstract:
A magnetic tape cassette of a two reel type comprising a reel around which a magnetic recording medium is wound, the magnetic recording medium comprising a support, a non-magnetic layer comprising a non-magnetic powder and a binder on one surface of the support, a magnetic layer comprising a ferromagnetic metal powder and a binder on top of the non-magnetic layer, and a back layer comprising a carbon black powder and a binder on the other side of the support, said magnetic tape cassette further comprising:a rotating guide roller made of a resin within the cassette, the roller being in contact with the surface of the magnetic layer; the ten-point average roughness Rz of the rotating guide roller being 3.0 to 4.5 &mgr;m; and the center plane average roughness SRa of the magnetic layer being 2.0 to 3.5 nm.