Abstract: A heat-assisted magnetic recording (HAMR) disk has multiple independent data layers, each data layer being a continuous non-patterned layer of magnetizable material. Each data layer can store data independent and not related to the data stored in the other data layers. The data layers are separated by a nonmagnetic spacer layer (SL) and each data layer is formed of high-anisotropy (Ku) material so that the coercivities of lower and upper data layers (RL1 and RL2) are greater than the magnetic write field. At a high laser power both RL1 and RL2 are heated to above their respective Curie temperatures and data is recorded in both RL1 and RL2. At low laser power only upper RL2 is heated to above its Curie temperature and data is recorded only in RL2. The SL prevents lower RL1 from being heated to above its Curie temperature at low laser power.

Abstract: A high performance perpendicular media with optimal exchange coupling between grains has improved thermal stability, writeability, and signal-to-noise ratio in a selected range of allowable intergranular exchange between the grains for high performing media. The writeability and byte error rate of a TaOx media are demonstrated to be substantially better than that of other designs.

Abstract: A laminated magnetic recording medium for data storage has an antiferromagnetically-coupled (AFC) layer and a single ferromagnetic layer spaced apart by a nonferromagnetic spacer layer. The AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling. In each of the two remanent magnetic states, the magnetic moments of the two antiferromagnetically-coupled films in the AFC layer are oriented antiparallel, and the magnetic moment of the single ferromagnetic layer and the greater-moment ferromagnetic film of the AFC layer are oriented parallel. The nonferromagnetic spacer layer between the AFC layer and the single ferromagnetic layer has a composition and thickness to prevent antiferromagnetic exchange coupling. The laminated medium has improved thermal stability and reduced intrinsic media noise.

Abstract: A digital pen that has an ink writing tip includes a laser on a pen body that directs light toward paper across which the writing tip is stroked. A CMOS camera or CCD is also mounted on the pen body for detecting reflections of the laser light, referred to as “speckles”. A processor in the pen body determines relative pen motion based on the speckles. A contact sensor such as an FSR on the pen body senses when the tip is pressed against the paper, with positions being recorded on a flash memory in the pen body when the contact sensor indicates that the pen is against the paper. The memory can be later engaged with a handwriting recognition device to correlate the positions to alpha-numeric characters. Ordinary paper can be used, but, if desired, special bar-coded paper can also be used, so that the recorded positions can be tagged with a page number, form field, and absolute position on the page.

Abstract: A method for writing data on a magnetic recording medium includes providing a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film, with one of the ferromagnetic films having a greater magnetic moment than the other. A positive write field is applied to a first region to align the moments of both ferromagnetic films with the positive field, and then a negative write field is applied to an adjacent region to align the moments of both ferromagnetic films with the negative field. When the medium is moved away from the write fields, the moment of the ferromagnetic film with the lesser moment in each region flips to be antiparallel to the moment of the other ferromagnetic film in its region. The result is that the adjacent regions become adjacent magnetized domains with the transition between the domains representative of the written data.

Abstract: A digital pen that has an ink writing tip includes a laser on a pen body that directs light toward paper across which the writing tip is stroked. A CMOS camera or CCD is also mounted on the pen body for detecting reflections of the laser light, referred to as “speckles”. A processor in the pen body determines relative pen motion based on the speckles. A contact sensor such as an FSR on the pen body senses when the tip is pressed against the paper, with positions being recorded on a flash memory in the pen body when the contact sensor indicates that the pen is against the paper. The memory can be later engaged with a handwriting recognition device to correlate the positions to alpha-numeric characters. Ordinary paper can be used, but, if desired, special bar-coded paper can also be used, so that the recorded positions can be tagged with a page number, form field, and absolute position on the page.

Abstract: A laminated magnetic recording medium for data storage has an antiferromagnetically-coupled (AFC) layer and a single ferromagnetic layer spaced apart by a nonferromagnetic spacer layer. The AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling. In each of the two remanent magnetic states, the magnetic moments of the two antiferromagnetically-coupled films in the AFC layer are oriented antiparallel, and the magnetic moment of the single ferromagnetic layer and the greater-moment ferromagnetic film of the AFC layer are oriented parallel. The nonferromagnetic spacer layer between the AFC layer and the single ferromagnetic layer has a composition and thickness to prevent antiferromagnetic exchange coupling. The laminated medium has improved thermal stability and reduced intrinsic media noise.

Abstract: A laminated magnetic recording medium for data storage uses a magnetic recording layer having at least two antiferromagnetically-coupled (AFC) layers spaced apart by a nonferromagnetic spacer layer. Each AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling of the second film to the first film. The magnetic moments of the two antiferromagnetically-coupled films in each AFC layer are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of each AFC layer is the difference in the Mrt values of the two ferromagnetic films. The nonferromagnetic spacer layer between neighboring AFC layers has a composition and thickness to prevent any antiferromagnetic coupling of the ferromagnetic films of one AFC layer with the ferromagnetic films of the neighboring AFC layer.

Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film. The magnetic moments of the two antiferromagnetically-coupled films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in the thermal stability of the recording medium because the volumes of the grains in the antiferromagnetically-coupled films add constructively. In a magnetic recording rigid disk application, the magnetic layer comprises two ferromagnetic films, each a granular film of a sputter deposited CoPtCrB alloy, separated by a Ru spacer film having a thickness to maximize the antiferromagnetic exchange coupling between the two CoPtCrB films.

Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film. The magnetic moments of the two antiferromagnetically-coupled films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in the thermal stability of the recording medium because the volumes of the grains in the antiferromagnetically-coupled films add constructively. In a magnetic recording rigid disk application, the magnetic layer comprises two ferromagnetic films, each a granular film of a sputter deposited CoPtCrB alloy, separated by a Ru spacer film having a thickness to maximize the antiferromagnetic exchange coupling between the two CoPtCrB films.

Abstract: A magnetic layer structure with a layer of cobalt-chromium-platinum-boron composite alloy containing 10% to 20% B in the magnetic layer. The useful magnetic properties of the magnetic layer structure are achieved by the incorporation of a nucleation layer prior to the deposition of the magnetic layer. The resultant magnetic layer structures have coercivity Hc values in between 2,000 and 5,000 Oe, grain sizes between 30 and 200 Angstroms and anisotropic crystallographic orientation with the c-axis of the cobalt-chromium-platinum-boron in the plane of the medium. These magnetic layer structures are suitable for magnetic data storage devices including magnetic disks.

Abstract: A laser-based inspection tool (LIT) for disks that allows simultaneous inspection of disk surfaces for defects and curvature. The laser beam is directed by a rotating scanner, such as a rotating polygon mirror, to the input of a telecentric lens assembly that provides an output beam parallel to its optical axis as the beam is being scanned. The output beam from the telecentric lens strikes the disk surface substantially perpendicularly. The beam is then reflected from the disk surface and passes back through a collection lens to the sensing surface of an optical detector. The detector outputs analog signals that represent the X and Y positions on the sensing surface where the reflected light beam is incident, which thus correspond to the slope of the disk surface at the point where the laser beam was incident. A mechanical disk lifter moves the disk in a plane parallel to the disk surface so that different scan lines can be generated on the disk surface.

Abstract: A glass disk substrate inspection tool uses a polarized laser beam that is directed to the first surface of the disk substrate at Brewster's angle and is then transmitted through the disk substrate to a light detector that generates a signal representative of the intensity of the light received. Because the light polarized parallel to the plane of incidence, i.e., the plane formed by the line of the incident beam and a line perpendicular to the surface of the disk substrate, is completely transmitted, there is no surface reflection at either the first or second surfaces of the disk substrate. The polarized beam is directed by a first rotating scanner to the input of a telecentric lens assembly that provides an output beam parallel to its optical axis as the beam is being scanned. The beam is then directed by a first fixed mirror to strike the first surface of the disk substrate at Brewster's angle as the beam is scanned along a line across the first disk surface.

Abstract: An optical disk data storage system uses an optical disk that has a plurality of substrates, each of which has a data surface. The laser light beam from the system is maintained on the data tracks of a selected one of the spaced-apart data surfaces by the use of tracking marks contained on the data surfaces. The system has a controller that identifies the type of data tracking used on the data surfaces from recorded tracking type information.

Abstract: A multiple recording layer rewriteable phase-change optical disk and disk drive uses a reverse writing type of reversible phase-change material as the recording layer nearest the incident laser light. The disk has a light-transmissive substrate onto which the laser light is incident. The substrate supports at least two spatially-separated multilayer recording stacks, each stack including an active recording layer of reversible or rewriteable phase-change material. The recording stack located nearest the substrate on which the laser light is incident includes a reverse writing type of reversible phase change material, i.e., a phase-change material with an amorphous starting phase that is recorded onto by laser heating that converts data regions to the crystalline phase.

Abstract: A multiple data layer optical medium, such as an optical disk, has a plurality of substrates, each of which has a data surface. The laser light beam from the optical data recording system is maintained on the data tracks of the two spaced-apart data surfaces by the use of tracking marks contained on the data surfaces. One of the data surfaces includes recorded information that identifies the type of tracking marks present.

Abstract: An optical data storage system comprises a multiple data surface medium and optical head. The medium comprises a plurality of substrates separated by a light transmissive medium. Data surfaces are located on the substrate surfaces. A layer of a semiconductor material is deposited onto each of the data surfaces. The thickness of the semiconductor layer determines the amount of reflectivity for each of the data surfaces.

Abstract: An optical data storage system comprises an optical disk drive and a multiple data surface magneto-optical medium. The medium comprises a substrate, a first dielectric layer, a first magneto-optical data layer, a second dielectric layer, a transmissive member, a third dielectric layer, a second magneto-optical data layer, a fourth dielectric layer, and a reflector layer. The thicknesses of the magneto-optical and dielectric layers are selected to maximize the magneto-optical read out signal received from the data layers. The disk drive includes a phase retarder for improving the signal from the magneto-optical data layers.