Abstract: In a magnetic recording member comprising a non-magnetic support having provided thereon a magnetic layer comprising finely divided ferromagnetic powders dispersed in a binder, in which the binder comprises about 10 to about 70 wt% of (a) a polyester-polyurethane resin and about 30 to about 90 wt% of (b) a synthetic non-drying oil modified alkyd resin and (c) a polyisocyanate, wherein the molar ratio of the isocyanate groups present in the polyisocyanate (c) to the hydroxyl groups present in the synthetic non-drying oil-modified alkyd resin (b) ranges from about 0.8:1 to about 2.0:1. The binder system in accordance with the present invention provides excellent magnetic properties, particularly improved squareness ratio and 5 MHz output. The binder system of the present invention also enables the use of finely divided ferromagnetic alloy powders, with excellent magnetic properties being maintained when magnetic recording members are produced therefrom.

Abstract: This invention relates to a magnetic recording medium comprising a ferromagnetic metal thin film as a magnetic recording layer on a non-magnetic flexible support, in which the surface roughness of the support is 0.10 .mu.m or less and the period of the surface roughness is v/10.sup.6 .mu.m or less where v represents a relative speed between a magnetic head and magnetic recording medium by .mu.m/sec. In the case of providing an undercoated layer between the magnetic recording layer and non-magnetic flexible support, the surface roughness of the undercoated layer is adjusted to 0.10 .mu.m or less and the period of the surface roughness is adjusted to v/10.sup.6 .mu.m or less.

Abstract: A system for the position control of a write-read head for information carriers with a magnetic storage layer, having optical servo tracks. The servo tracks consist of periodically interrupted lines, whose period length is constant and whose phase relationship differs for adjacent servo tracks. An optical scanner is connected to the magnetic write-read head and is provided with a diaphragm which transmits at the most one line section and at least one overlap between two adjacent line sections to the scanner.

Abstract: This invention provides a magnetic recording material having a regular orientation which comprises aluminum or aluminum alloy on the surface of which a film having a great number of micro pores is formed by an anodic oxidation, each of said pores being packed with a magnetic substance. As compared with conventional magnetic recording materials, this magnetic recording material is excellent in anisotropy, ability to effect high density recording, uniformity of unit magnetic elements in size and dimension ratio with regular orientation, and highness of leakage flux.

Abstract: An improved magnetic recording member of the disc type. The article of the invention is formed, preferably, of metallic magnetic particles oriented in a vertical direction. This combination overcomes existing limitations on (a) disc products, and (2) the preferred metallic particles heretofore known.

Abstract: A magnetic recording tape of improved properties comprising a non-magnetic support and a two-layered magnetic coating composed of a ferromagnetic powder and a binder and formed on one surface of the support, wherein the lower magnetic layer has a coercive force of about 250 to about 300 Oe, a residual magnetic flux density of at least about 1,500 Gauss and a dry thickness of at least about 2.5 .mu.m, and the upper magnetic layer has a coercive force of about 350 to about 400 Oe, a residual magnetic flux density of not more than about 1,500 Gauss and a dry thickness of about 2.0 to 3.0 .mu.m, the ferromagnetic powder in the upper magnetic layer having an APP value of not more than 1.0.

Abstract: The magnetic recording medium comprising a nonmagnetizable base having provided thereon a magnetizable layer by electroless plating, said magnetizable layer containing at least one ferromagnetic metal, phosphorus and at least one of copper, lead and silicon.

Abstract: Magnetic storage means which may be a disc having a magnetic storage layer coated with a protective layer. The protective layer, which is preferably an inorganic oxide material, protects the magnetic storage layer from corrosion. A lubricant is applied to the protective layer and serves to reduce wearing due to frictional drag between the disc and a cooperating magnetic head (or heads). The lubricant is oriented so as to make very good adherence with the oxide sublayer and thereby prevent removal of the lubricant through continued use and/or cleaning.

Abstract: A magnetic recording medium comprising a magnetic sheet of domain sized particles of at least one member selected from the group consisting of barium ferrite, strontium ferrite and lead ferrite, dispersed uniformly in an organic binder, and a ferromagnetic plate bonded to one surface with the other surface of the sheet being magnetizable at selected sites with the magnetization being in a direction substantially perpendicular to the surfaces.

Abstract: An apparatus for recording and/or reproducing video signal information employs, as a record medium, a sheet assembly composed of at least two normally closely adjacent, confronting flexibly resilient sheets which provide mutual protection, when in that relation, for video signal information recorded, for example, magnetically, on at least one of the sheets.

Abstract: A magnetic oxide film manufacturing method is disclosed which involves the steps of sputtering a target made of iron and aluminum to form a film of non-magnetic iron oxide (.alpha.-Fe.sub.2 O.sub.3) and reducing the film to obtain a magnetic oxide film. When a target made of iron and aluminum is employed, it is possible to obtain a high coercive force magnetic oxide film which is highly adhesive to a substrate, excellent in surface roughness and less than 0.3.mu.m in thickness. Accordingly, it is possible to obtain a magnetic disk of high magnetic recording density.

Abstract: An improved method of making a magnetic recording medium with excellent coercive force and rectangular ratio is provided by means of an ion plating technique. A support and an evaporation source of a magnetic Co-Si alloy are placed in an ion plating apparatus which is filled with an inert gas and kept at low vacuum. High voltage is then applied between the support and the evaporation source such that the former has a negative polarity and the latter a positive polarity, thereby causing a glow discharge zone in the apparatus. The magnetic alloy is evaporated into the glow discharge zone from the source to form a magnetic thin film on the support. Such a magnetic thin film can have a coercive force of 750 Oe or more and a rectangular ratio of 0.80 or more and can be used as a magnetic recording medium.

Abstract: A first thin film of appropriate texture, lattice constant, and crystal structure, such as body centered cubic vanadium or chromium with (110) texture is deposited upon a rigid or flexible substrate forming a plurality of polycrystals. A ferrite such as magnetite (Fe.sub.3 O.sub.4) is sputtered from a target onto the first thin film forming a mixture of .gamma.Fe.sub.2 O.sub.3 and Fe.sub.3 O.sub.4 substantially completely without formation of Fe or other oxides of iron, providing good magnetic characteristics and resistance to corrosion. The substrate temperature can be maintained as low as 200.degree.C for both steps when sputtering or evaporation is employed.

Abstract: A magnetic recording medium having at least two particle populations that may be either contained in a single layer of magnetic medium or a dual layer of magnetic medium. In a first embodiment one of the particle populations of the medium is formed of conventional magnetic recording particles and the other population is highly anisotropic. In a second embodiment both particle populations are highly anisotropic but they are aligned so that the easy axes of magnetization of the populations are at an angle to one another. Also disclosed is a machine readable magnetic recording document that employs the magnetic recording medium of the present invention, and an apparatus for reading such document and validating the same.

Abstract: A magnetic recording medium having uniaxially highly anisotropic particles with an easy axis intrinsic coercive force of less than 1900 oersteds. Also disclosed is a machine readable magnetically encoded document employing the medium of the present invention and an apparatus for reading such document and validating the same.

Abstract: Magnetic recording apparatus employing a medium characterized by having a relatively high coercivity recording layer having servo tracks recorded therein, and a second layer of lower coercivity in which data may be recorded. The servo tracks are read by a head and this signal is used to properly position the head for writing and reading of data. If the medium is a disc, e.g. the servo tracks may be either concentric circles or a single spiral concentric with the center of the disc.

Abstract: An electrolytic plating solution and method for depositing ferromagnetic recording films therefrom is described. The plating solution has cobaltous ion in the range of from about 3 to 15 grams per liter, nickelous ion in the range of from about 30 to 50 grams per liter, and orthophosphite ion in the range of from about 3 to 12 grams per liter. It is important that the ratio of nickelous ions to cobaltous ions be in the range of from about 3:1 to about 15:1. The plating solution is substantially free of hypophosphite ion, phosphate ion, copper and iron so that phosphite ion is the sole source of phosphorus. Optionally the solution may contain up to about 30 grams per liter of boric acid and up to about 25 grams per liter of formate ion. The pH of the solution is maintained in the range of from about 3.5 to 4.7.