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AssigneeFuji Photo Film Co., Ltd.
InventorsHiroaki Doushita, Yasutoshi Okuzawa, Tadashi Ishiguro, Takeshi Kakuta, Kazuo Kato
Estimating the term…
A magnetic tape cassette whose reliability is considerably improved by preventing triboelectrification by tape-and-guide friction. A metal tape guide for guiding the magnetic tape while in contact with the back surface of the tape. The substrate of the magnetic tape is made of polyethylene terephthalate or polyethylene naphthalate, and has a surface specific resistance R.sub.s of 10.sub.8 .OMEGA./cm.sup.2 or more. The tape guide is made of stainless steel or aluminum, and the surface roughness of the tape guide is such that the root mean square roughness value R.sub.rms, as determined by height from a reference surface, is 60 nm or lower. Also, the back surface of the tape may be provided with 30 to 400 protrusions of a height of 300 nm per 0.1 mm.sup.2.
In a magnetic tape cassette having a metal tape guide for guiding a magnetic tape, the magnetic tape comprising a substrate and a magnetic layer provided on a front surface of the substrate, the guide being in direct contact with a back surface of the substrate, and in which the substrate is made of a material comprising one of polyethylene terephthalate and polyethylene naphthalate, the improvement wherein a surface specific resistance R.sub.s of the back surface of the substrate is at least approximately 10.sup.8 .OMEGA./cm.sup.2, the tape guide is made of a material comprising one of stainless steel and aluminum, and a surface roughness of the tape guide is such that a height of a highest one of a plurality of protrusions on the surface of the tape guide measured from a reference surface for determining a root mean square roughness value R.sub.rms is no greater than approximately 60 nm.
Dependencies are inferred from the claim text.