1078results about How to "Improve recording density" patented technology

The magnetic tape has a timing base servo pattern on the magnetic layer, wherein the centerline average surface roughness Ra on the surface of the magnetic layer is less than or equal to 1.8 nm, the magnetic layer contains a fatty acid ester, the full width at half maximum of spacing distribution measured by optical interferometry on the surface of the magnetic layer before and after vacuum heating the magnetic tape is greater than 0 nm but less than or equal to 7.0 nm, the difference of spacing measured by optical interferometry on the surface of the magnetic layer after and before vacuum heating the magnetic tape is greater than 0 nm but less than or equal to 8.0 nm.

A patterned perpendicular magnetic recording medium has magnetic islands that contain stacks of individual magnetic cells to provide multilevel recording. Each cell in an island is formed of a material or set of materials to provide the cell with perpendicular magnetic anisotropy and is a single magnetic domain. Each cell is magnetically decoupled from the other cells in its island by nonmagnetic spacer layers. Thus each cell can have a magnetization (magnetic moment) in one of two directions (into or out of the plane of the layer making up the cell), and this magnetization is independent of the magnetization of the other cells in its island. This permits multiple magnetic levels or states to be recorded in each magnetic island.

A microwave assisted magnetic recording head includes a recording magnetic pole unit that produces a recording field for writing to a perpendicular magnetic recording medium, and a high-frequency magnetic field oscillator that produces a high-frequency magnetic field. The recording magnetic pole unit includes a magnetic core with a write gap portion at which a main recording field component is concentrated, and the high-frequency magnetic field oscillator is disposed in the write gap.

A hologram recording material is provided and includes at least a sensitizing dye capable of absorbing light having a hologram recording wavelength to generate an excited state thereof, and an interference fringe-recording component capable of recording interference fringes providing a refractive index modulation by an electron transfer or an energy transfer from the excited state, in which the sensitizing dye in the hologram recording material has a molar absorption coefficient within a range of 1 to 10,000 at the hologram recording wavelength.

A perpendicular magnetic recording medium 100 has, over a substrate, at least a magnetic recording layer 122 with a granular structure in which nonmagnetic grain boundaries are formed between magnetic grains continuously grown into a columnar shape. The magnetic grains of the magnetic recording layer 122 contain Co, Cr, and Pt. The magnetic recording layer 122 contains at least one oxide selected from a group A including SiO2, TiO2, and Cr2O3, at least one oxide selected from a group B consisting of oxides each having a larger Gibbs free energy ΔG than the group A, and a reducing agent adapted to reduce the oxides of the group B.

It is an object to manufacture magnetic recording media with the high recording density. Since nonmagnetic portions (8) with a predetermined pattern are formed in a recording auxiliary layer (4) formed on a magnetic recording layer (3), it is possible to actualize a magnetic recording medium where magnetic portions (7) and the magnetic recording layer (3) immediately below the portions (7) are recording units. The nonmagnetic portions (8) are formed by non-magnetization using ion implantation, and it is thereby possible to manufacture magnetic recording media with the high recording density.

A method for recording information on a recording medium utilizing an interference pattern by interference between an information light modulated spatially with digital pattern information displayed on a spatial light modulator having multiple pixels and a reference light for recording. In order to provide a novel recording method capable of enhancing the recording density and the transfer rate furthermore, digital information to be recorded is represented by match / mismatch of the attributes of adjacent pixels in the spatial light modulator to produce digital pattern information.

A perpendicular magnetic recording medium includes a magnetic recording layer 22 having a granular structure composed of crystal grains containing cobalt (Co) and grown in a columnar shape and a grain boundary portion comprising a nonmagnetic substance and formed between the crystal grains, and a continuous layer 24 of a thin film magnetically continuous in a film plane direction. The continuous layer 24 includes a plurality of layers 24a and 24b containing cobalt, chromium (Cr), and platinum (Pt). Among the layers, the layer 24a nearer to the magnetic recording layer has a greater chromium content.

A characteristic evaluation method of a perpendicular magnetic recording medium suitable for obtaining a perpendicular magnetic recording medium which can respond to much higher recording density is provided.This is an evaluation method of a perpendicular magnetic recording medium, including a process of recording a first signal of a specific frequency at an arbitrary first position in the perpendicular magnetic recording medium; a process of measuring a reproduction output of the first signal and of measuring a signal / noise ratio (initial value) of the first signal at a peak position where the reproduction output becomes the maximum; a process of recording a signal of a specific frequency at a second position away from the first position by a predetermined distance in the radial direction of the perpendicular magnetic recording medium; a process of measuring the signal / noise ratio of the first signal at the peak position again; a process of repeating the process of recording the signal of the specific frequency at a position brought close to the first position from the second position by a predetermined distance and of measuring the signal / noise ratio of the first signal at the peak position again while sequentially getting closer to the first position from the second position; and a process of determining whether the value of the signal / noise ratio has lowered from the initial value by a predetermined range or more.

[PROBLEMS] To provide a process for producing a magnetic recording medium, which can simultaneously realize increased high recording density, high impact resistance, and prevention of corrosion, by providing an underlayer which, even when formed at a low gas pressure, can exhibit a high level of coercive force.[MEANS FOR SOLVING PROBLEMS] A process for producing a perpendicular magnetic recording medium, comprising the step of forming a nonmagnetic underlayer (18) having a granular structure, in which crystal particles are grown in a column form, on a substrate, and forming a magnetic recording layer (20) having a granular structure in which magnetic particles are grown in a column form. The process is characterized in that the underlayer (18) is any one of CoCr or CoCrX (wherein X is a nonmagnetic material), CoCr-oxide, and CoCrX-oxide, and the film forming gas pressure of the underlayer (18) is not more than 4 Pa.