Abstract: A magnetic tape which comprises a nonmagnetic support, a magnetic layer which is formed on one surface of the nonmagnetic support, and a backcoat layer which comprises a binder and nonmagnetic powder containing carbon black as a component and which is formed on the other surface of the nonmagnetic support, having pits for optical servo formed thereon, characterized in that the average of the reflectance on the flat portion of the backcoat layer is 8.5% or higher, and that the maximum rate of fluctuation of the reflectance on the flat portion, depending on a position of the magnetic tape: [Maximum of absolute value of (Reflectance?Average reflectance)]×100/(Average reflectance) is 10% or lower. This magnetic tape is high in the initial S/N of the servo signal, and also high in the S/N of the servo signal found after the magnetic tape is run twice.

Abstract: A cleaning structure for removing dust is constituted of a guiding member having a sliding surface for guiding run of a tape, and a vacuum pressure supply source for making a vacuum pressure effect on a suction space provided inside the guiding member and so on. At the sliding surface of the guiding member, a suction port for making the suction space communicate with an external space is formed, and the opening edge of the suction port on the downstream side in the tape running direction is served as a first dust removal portion for removing dust on the tape surface. The guiding member has a guiding wall having a contact surface which guides at least one tape edge of a tape, and the contact surface is served as a second dust removal portion for removing dust adhering to the tape edge.

Abstract: A magnetic tape which comprises a nonmagnetic support, a magnetic layer which is formed on one surface of the nonmagnetic support, and a backcoat layer which comprises a binder and nonmagnetic powder containing carbon black as a component and which is formed on the other surface of the nonmagnetic support, having pits for optical servo formed thereon, characterized in that the average of the reflectance on the flat portion of the backcoat layer is 8.5% or higher, and that the maximum rate of fluctuation of the reflectance on the flat portion, depending on a position of the magnetic tape: [Maximum of absolute value of(Reflectance?Average reflectance)]×100/(Average reflectance) is 10% or lower. This magnetic tape is high in the initial S/N of the servo signal, and also high in the S/N of the servo signal found after the magnetic tape is run twice.

Abstract: A magnetic tape which comprises a nonmagnetic support, a magnetic layer which is formed on one surface of the nonmagnetic support, and a backcoat layer which comprises a binder and nonmagnetic powder containing carbon black as a component and which is formed on the other surface of the nonmagnetic support, having pits for optical servo formed thereon, characterized in that the average of the reflectance on the flat portion of the backcoat layer is 8.5% or higher, and that the maximum rate of fluctuation of the reflectance on the flat portion, depending on a position of the magnetic tape: [Maximum of absolute value of (Reflectance?Average reflectance)]×100/(Average reflectance) is 10% or lower. This magnetic tape is high in the initial S/N of the servo signal, and also high in the S/N of the servo signal found after the magnetic tape is run twice.

Abstract: A cleaning structure for removing dust is constituted of a guiding member having a sliding surface for guiding run of a tape, and a vacuum pressure supply source for making a vacuum pressure effect on a suction space provided inside the guiding member and so on. At the sliding surface of the guiding member, a suction port for making the suction space communicate with an external space is formed, and the opening edge of the suction port on the downstream side in the tape running direction is served as a first dust removal portion for removing dust on the tape surface. The guiding member has a guiding wall having a contact surface which guides at least one tape edge of a tape, and the contact surface is served as a second dust removal portion for removing dust adhering to the tape edge.

Abstract: An information recording medium has such error detecting codes that the distance between the codes of adjacent tracks of the medium is always 1. The bits E1-Em of the detecting codes, which are included by pre-format information, are generated as data trains of parity check bits constructed by dividing the bits S1-Sm of the sector numbers and the bits T1-T2 of the track numbers. If the generated detecting codes are compared between adjacent, tracks, the distance between the codes is always 1. Consequently, when the detecting codes of a desired track are read out, substantially no cross talk occurs from the detecting codes of the adjacent tracks. Therefore, even if the recording medium has a narrow track pitch, it is possible to reliably and accurately detect the errors of address data of the medium.

Abstract: A laminated stretch wrap film comprising an intermediate layer and two outer layers wherein (i) the intermediate layer is comprised of polyethylene having a density equal to or less than 0.910 gram per cubic centimeter blended with about 5 to about 30 percent by weight polypropylene, the percent by weight being based on the combined weight of the polyethylene and polypropylene; and (ii) the outer layers are comprised of ethylene-vinyl acetate copolymer.

Abstract: A plastic film is formed by annealing a molten tubular film in a first enclosed space and immediately thereafter directing cold air perpendicular to the axis thereof and expanding and solidifying the film in a second enclosed space while in contact with cold air flowing parallel to film travel.