Matches 551 - 600 out of 1104 < 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 >
Match Document Document Title
4911967 Substrate for magnetic disk memory and production process  
Substrate for magnetic disk memory and production process. The substrate comprises an aluminium wafer (10) and two plastic sheets (39,41) pressed hot against the wafer. The outer faces (38,40) have...
4910625 Article surveillance apparatus and systems for computer data disks  
An article surveillance marker suitable for use on computer magnetic data disks is disclosed in which the marker, a length of low coercivity, high magnetic permeability ferromagnetic material is...
4910617 Disk drive head positioning servo system utilizing encoded track zone information  
The invention is directed to a head positioning servo system for disk drives employing a dedicated servo surface. A plurality of servo cells are recorded on the servo surface each including a sync...
4908727 Disk with substrate of alumina silicate resin glass  
A vertical recording system using a rigid disk medium with high recording density has a substrate made of alumina silicate resin glass and a vertical magnetic anisotropic film located on said...
4900397 Production of magnetic recording media  
Magnetic recording media essentially consisting of a disk-shaped aluminum substrate, a nonmagnetic (Ni-P) lower film, a chromium-containing intermediate film and a ferromagnetic metal film are...
4900380 Process for producing information recording medium  
A process for producing an information recording medium such as an optical disc comprises the steps of: putting a disc-shaped resin film having a hole at its central part upon a surface of a...
4897134 Ultrasonic welding hubs to magnetic recording diskettes  
A magnetic recording medium disk with substantially improved tolerances comprising: a hub including a center portion and recessed flange portion, the center portion having a planar drive...
4896240 Magnetic disk having an index area and a limited number of radially extending servo sections  
A magnetic disk, which is used for recording and reproducing data with a read/write head. The magnetic disk has an index area with an index signal recorded therein and a plurality of servo sectors...
4887179 Substrate for rigid disk storage media and method and apparatus for making the same  
A substrate including a disk having a pair of opposed faces and being coined to provide a sub-micron flatness and smoothness for the disk faces. The coined disk can then be coated with a layer of...
4887178 Aligned stretched surface recording medium  
Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 44 and 32 at or near its inside and outside diameters 22 and 30 with a base portion 24 in...
4885653 Disk cartridge with a hub having an outsert molded control ring  
A disk cartridge comprises a case and a disk encased in the case, the disk having a hub comprising a flange of thin metal sheet and a control ring integrated with the flange by outsert molding the...
4871606 Magnetic recording medium  
A magnetic recording medium having high running stability and good magnetic characteristics without causing an abrasion problem, which comprises a base film, a magnetic layer provided on one...
4871404 Method for producing an optical information recording disk  
A method for manufacturing an optical information recording disk having a reduced eccentricity between the center hole of the disk and the recorded track. A transparent circular substrate is...
4870524 Substrate for rigid disk storage media  
A substrate including a disk having a pair of opposed faces and being coined to provide a sub-micron flatness and smoothness for the disk faces. The coined disk can then be coated with a layer of...
4868261 Optical resin material  
An optical resin material comprising a polymer containing as an essential component at least one norbornyl acrylate or methacrylate or a derivative thereof is excellent in properties, particularly...
4861656 Optical recording medium  
An optical recording medium comprising a recording layer on a substrate is more durable when an intermediate layer of a composition comprising a rare earth element oxide, silicon oxide, and silicon...
4858036 Software protection and identification system  
A method of protecting machine readable signals recorded on magnetic recording media from unauthorized duplication and use. The signals to be protected are recorded on a first portion of the...
4855020 Apparatus and method for the electrolytic plating of layers onto computer memory hard discs  
An apparatus for the electrolytic plating of computer memory discs comprising a plating container for the receipt of a liquid plating bath, a spindle fitted to the plating container, a prime mover...
4839953 Magnetic disk cartridge assembly system  
A magnetic disk cartridge is provided with a dust shutter which is slidably mounted on a casing to open and close a magnetic head access opening in the casing . A V-shaped shutter spring for urging...
4836890 Method for producing optical information recording disk  
A method for manufacturing an optical information recording disk having a reduced eccentricity between the center hole of the disk and the recorded track. A transparent circular substrate is...
4835647 Stretched surface recording medium  
Stretched surface recording disk (SSR) 10 comprising an annular support 12 having raised annular ridges 28 and 42 at its inside and outside diameters 22 and 30 with a base portion 24 in between the...
4829799 Method of manufacturing substrate for memory disk  
A method of manufacturing a substrate for a memory disk characterized in that a blank material comprising a non-magnetic metal substrate covered with a non-magnetic metal as an underlayer is...
4827470 Information memory medium  
An optical disk comprising a disk-like body having two base plates made of synthetic resin and two recording layers formed on the base plates, respectively. The body is formed by bonding the base...
4827468 Information memory medium  
An information memory medium adapted for processing information with a drive mechanism including a turntable which has a support surface and a magnetic attraction member. The information memory...
4825680 Method of manufacturing metal substrates for disk for memory storage media  
A method for manufacturing a metal substrate for a memory disk wherein a metal blank material (6) is sandwiched between two dies within a metal mould (3) limiting the extent to which the material...
4825310 Method and apparatus for recording servo synchronization information  
A servo system for flexible magnetic disks such that the synchronization pulses do not have to be perfectly aligned. The disk is encoded such that consecutive servo tracks alternate between having...
4823578 Method of manufacturing substrate for memory disk  
A method of manufacturing a substrate for a memory disk characterized in that a blank material comprising a non-magnetic metal substrate covered with a non-magnetic metal as an underlayer is...
4823212 Sampled servo code format and system for a disc drive  
The system and method for normalizing the amplitude of servo code derived signals in a disc drive, includes an improved embedded servo code format of separate magnetic dibit fields, recorded in...
4814928 Information recording disk provided with distinguishing mark  
An information recording disk comprising a disk-like substrate and magnetic layers formed on both surfaces of the substrate is provided with a mark punched through the disk. The mark is provided...
4812939 Magnetic recording disc having tensioned and elastically-supported recording surface  
A magnetic recording disc having a rigid substrate disc is provided with an annular recess defined between inner and outer peripheral bonding rings. One or more annular elastic discs having a...
4805065 Particulate magnetic recording media having an areally controlled recording characteristics  
Utilizing the technique whereby particulate media electrodeposited at a critical electric field intensity has a given packing density, and when electrodeposited at a lesser electric field intensity...
4803577 Vertical magnetic recording system using rigid disk  
A vertical recording system using a rigid disk medium with high recording density has a substrate made of alumina silicate resin glass and a vertical magnetic anisotropic film located on said...
4802050 Magnetic recording medium  
A magnetic recording medium is disclosed wherein the data tracks are formed of magnetic layers and the non-data tracks are formed of non-magnetic layers. The data tracks and non-data tracks are...
4802047 Disc cartridge  
A disc cartridge capable of effectively preventing a shutter from being opened even when any unexpected shock is suddenly applied to the disc cartridge during non-use of the disc cartridge. The...
4800458 Recording sheet bonded to a substrate in a magnetic disk  
A recording disk in which on each side of a substrate an inner and outer mounting ring extends above the surface of the substrate. A flexible recording sheet is adhesively bonded to the mounting...
4799114 Thermomagnetic recording carrier and a method for thermomagnetic recording  
A new thermomagnetic recording medium is presented. The medium comprises a substrate and a pair of layers, one of which is comprised essentially of Gd-alloys. A layer wherein Gd-alloys is used...
4797764 Recording disk with low total indicated runout  
A magnetic recording medium disk with substantially improved tolerances comprising: a hub including a center portion and recessed flange portion, the center portion having a planar drive surface;...
4796141 Disc assembly for a magnetic disc apparatus  
A disc assembly for a magnetic disc apparatus comprises a plurality of vertically arranged magnetic discs each having a central aperture, a rotating shaft which is inserted in the central aperture...
4791515 Protecting a disc cartridge from inadvertent actuation during nonuse  
A disc cartridge capable of effectively preventing opening of a shutter and damage of a disc therewithin, even when any unexpected shock is suddenly applied to the disc cartridge during non-use of...
4788615 Means for adhering the magnetic disk to the center core in a magnetic disk cartridge  
A magnetic disk assemblage rotatably housed in a magnetic disk cartridge comprises a center core which is cylindrical in shape and is provided with a floor, in the center of which is a hole for a...
4785444 Optical recording disc  
An optical recording disc in which a disc substrate made of a synthetic resin having a light transmittance and a hub made of a synthetic resin, fixed to a center part of the disc substrate by means...
RE32781 Flexible disk cassette with improved radial shift limitation structure for use in a magnetic recording and/or reproducing apparatus  
A flexible magnetic disk cassette includes a flexible magnetic disk. A center core disk is also provided having a center hollow and raised fringe, and is attached at a center of the flexible...
4779160 Magnetic recording disk  
A magnetic recording disk comprises a disk base which is provided with a central opening and an annular recess formed on at least one side thereof between the inner peripheral edge portion...
4764828 Disc and hub centering device for use in magnetic disc drives  
Each spacer separating adjacent discs in a magnetic disc drive includes an insert having a body portion having a height equal to the height of the spacer and with a plurality of finger portions...
4761874 Method of making magnetic recording medium  
A method of making a magnetic recording medium comprises a first step of polishing a surface of a strip-like magnetic recording medium composed of a substrate and a magnetic layer formed on a...
4748524 Alignment disk for use in adjusting or inspecting a magnetic head in a floppy disk drive unit  
In an alignment disk for use in adjustment or inspection of a magnetic read/write head in a floppy disk drive unit, which further includes an erase head, the alignment disk is provided with first...
4745510 Perpendicular magnetic recording and reproducing system  
A perpendicular magnetic recording and reproducing system records and reproduces a signal on and from a perpendicular magnetic recording medium comprising a magnetic layer which is made from one...
4742421 Magnetic recording disc having tensioned and elastically-supported recording surface  
A magnetic recording disc having a rigid substrate disc is provided with an annular recess defined between inner and outer peripheral bonding rings. An annular elastic disc having a thickness...
4742420 Magnetic disk with a porous substrate  
A magnetic recording disk having a rigid substrate disc is provided with an annular air gap defined between inner and outer peripheral bonding rings. A flexible disc sheet having a recording...
4739426 Disk drive system  
A disk drive system according to the present invention comprises a spindle in a drive unit. The spindle is formed, at its free end, so that it has a flat portion. A magnetic disk which is adapted...
Matches 551 - 600 out of 1104 < 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 >