Abstract: A base film for a magnetic recording medium including one surface, on which a magnetic layer can be formed, having a surface roughness of center line average roughness Ra of 10 nm or less, a ten-point average roughness Rz of 80 nm or less and a maximum height Rmax of 150 nm or less. The base film includes the other surface having a surface roughness of center line average roughness Ra of 4.5 to 20 nm, a ten-point average roughness Rz of 35 to 350 nm and a maximum height Rmax of 40 to 400 nm.

Abstract: The quantity of impurities in a magnetic material is decreased to produce a magnetic material with good quality, and a decrease in the cost of the magnetic material is realized by desulfurization. A magnetic raw material for metallic thin film magnetic recording media which contains sulfur more than 20 ppm is desulfurized to obtain the magnetic material for metallic thin film magnetic recording media with the sulfur content adjusted to 20 ppm or below, and a metallic thin film magnetic recording medium having a magnetic layer vaporized thereon with the magnetic material is fabricated.

Abstract: A magnetic recording medium, comprising a nonmagnetic substrate on the surface of which is deposited a magnetic layer. In one embodiment, the magnetic layer is formed of two thin films of magnetic metal and a layer of nonmagnetic material sandwiched therebetween, the layer of nonmagnetic material having a thickness no greater than 20% of the thickness of the magnetic layer, with the magnetic layer having an energy product of at least 100 gauss.multidot.cm.multidot.Oe as the product of its residual magnetic flux density, thickness and coercive force, and a surface roughness no greater than 0.003 .mu.m in center line average height. In another embodiment, the magnetic layer, which may be a single layer of magnetic metal film or may be of the aforementioned multiple layer construction, is vacuum deposited onto the substrate at an incident angle in the range of 30.degree. to 70.degree..

Abstract: A method for magnetically recording digital video signals includes the steps of: converting input digital video signals into data segmented into blocks each composed of a plurality of pixel data; compression-coding the blocks of pixel data block-by-block; converting the compression-coded data into channel-encoded data; and supplying the channel-encoded data to magnetic heads on a rotary drum for recording by such heads on a magnetic recording medium constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 75 G.cm.Oe, with the surface roughness of said magnetic recording medium being at most 0.003 .mu.m in center line average height Ra, and with the surface roughness of said magnetic recording medium being at most 0.04 .mu.m in ten point average height Rz.

Abstract: A magnetic recording medium comprised of a nonmagnetic support; a magnetic metal thin film formed on one major surface of the nonmagnetic support; and a protective film of a corrosion-resistant metal or a multilayer protective film structure consisting of a corrosion-resistant metal film and a durable protective film of a hard material. A multilayer protective film structure is formed by sputtering a corrosion-resistant protective film and a durable protective film over the magnetic metal thin film while the nonmagnetic support travels along the circumference of a cooling cylinder by using at least one target of a corrosion-resistant metal and at least one target of a hard material, or by using a composite target composed of at least one corrosion-resistant metal and one hard material. The protective film suppresses the corrosion of the magnetic metal thin film and improves the corrosion resistance and durability of the magnetic recording medium.

Abstract: A magnetic recording medium having a magnetic metal thin film as a magnetic layer is disclosed. An oxide layer is formed on the surface of the magnetic metal thin film, and a proactive layer is further formed on the oxide layer. The oxide layer on the surface of the magnetic metal thin film has a thickness of 20 to 230 .ANG., while the protective layer has a thickness of 20 to 230 .ANG.. The combined total thickness of the oxide layer and the protective layer is 40 to 250 .ANG.. The oxide layer surface may be bombarded prior to formation of the protective layer for improving the bonding of the protective layer. A lubricant may be coated on the surface of the protective layer. The lubricant may be one of perfluoro alkyl ester of carboxylic acid, ester compounds of perfluoro polyether having carboxylic groups, and amine salt compounds. The reverse surface of a non-magnetic base film as a substrate has a centerline mean roughness R.sub.a and the maximum height R.sub.max of projections in the ranges of 0.015 .mu.

Abstract: A magnetic recording medium comprising a non-magnetic support, a magnetic metal thin film formed on one surface of the non-magnetic support and a back coating layer formed on the opposite surface of the non-magnetic support. The back coating layer is composed of non-magnetic pigment powders containing carbon powders and a binder, and the content of the carbon powders based on the total weight of the non-magnetic pigment powders is not less than 20 wt %. The weight ratio of the non-magnetic pigment powders to the binder is 0.5 to 2, while the coating thickness of the back coating layer is not less than 0.2 .mu.m. The surface resistivity of both the magnetic metal layer and the back coating layer is not higher than 10.sup.6 .OMEGA./sq. The stable running performance may be achieved even if the thickness of the back coating layer is reduced, if within a range of 0.2 .mu.m or higher.

Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.

Abstract: A magnetic recording apparatus of a digital picture signal comprising a block segmenting circuit for converting an input digital picture signal into data segmented by blocks composed of a plurality of picture elements, an encoding circuit for compressing and encoding the output data of the block segmenting circuit by blocks, and a channel encoding circuit for channel encoding the encoded output data from the encoding circuit, wherein the output data from the channel encoding circuit is recorded on a magnetic tape by a magnetic head mounted on a rotation drum, and wherein the magnetic recording apparatus of digital picture data is characterized in that the track pitch formed on the magnetic tape by the magnetic head is 5.5 .mu.m or less, the diameter of the rotary drum is 25 mm or less, and the rotating speed of the rotary drum is 150 rps or more, the track length per unit time is set to particular value thereby.

Abstract: A magnetic recording and reproducing method for enhancing picture quality and other characteristics while suppressing the difference in reproduction output between two heads. The method involves using a double azimuth head arrangement for signal recording and reproduction by helical scan. The two heads A and B are provided so that their azimuth angles .theta..sub.A and .theta..sub.B do not coincide with each other. The actual recording direction represented by the sum of the azimuth angles .theta..sub.A and .theta..sub.B on the one hand and a still angle .alpha. between the heads A and B on the other is made as close to the direction of magnetic particle orientation on the magnetic recording medium as possible.

Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.

Abstract: A magnetic tape for the recording of digital video signals is constituted by a nonmagnetic base having thereon a magnetic layer of at least one thin magnetic metal film which has an energy product of at least 100 G.cm.Oe, and with the surface roughness of the magnetic tape being at most 0.003 .mu.m in center line average height. Such tape, when used with magnetic heads each having a gap defined between portions of the respective head having a saturation magnetic flux density of at least 14 kG., contribute to the maintenance of an acceptable raw error bit rate below 1.times.10.sup.-4 when recording with a recorded bit area of no more than 1.25 .mu.m.sup.2 /bit.

Abstract: A magnetic recording transfer method for use with the combination of a mother magnetic recording medium and a copy magnetic recording medium of a metal-deposited thin film type each. The two media are overlaid so that the column inclination of one medium will be opposite in direction to that of the other medium. This method comprises the step of externally applying a biased magnetic field to the combination of the media in such a manner that magnetized recordings on the mother medium will be transferred to the copy medium. The easy axis of the mother medium is positioned at an angle of 20.degree..+-.15.degree. with respect to the in-plane direction of the medium. The biased magnetic field is applied to the mother medium at an angle of 110.degree..+-.15.degree. with respect to the in-plane direction of the medium.