摘要:
A disk system comprising an upper and lower head gimbal assembly, a coarse positioning servo system that includes a stepper motor for 135 TPI operation and a voice coil motor type servo for 1251 TPI operation that is driven by a optical servo system which locates optical track positioning information previously recorded on 3.5 inch microfloppies. The optical system focuses a spot of infrared light on the microfloppy which is channeled back to a detector. Each head gimbal includes a ceramic slider with two air bearing surfaces. A very high density magnetic core is positioned in one air bearing surface and high density magnetic core is located in the other air bearing surface. Both upper and lower sliders are such that the floppy disk media is pinched between them. The gaps of the magnetic cores are positioned within the leading edge half of their respective air bearing surfaces and take advantage of the tendency of the sliders to plow into the floppy disk media. The very high density and high density cores are offset differently from the centerline of the sliders to reduce crosstalk coupling between heads on opposite sides of the floppy disk media.
摘要:
A method for inscribing data onto a magnetic medium (12) wherein portions of an oxide coating (16) of the medium are removed from the medium (12) to create voids (88) while the oxide coating (16) is left undisturbed on areas adjacent to the voids (88). The adjacent areas are then uniformly magnetized. When the medium is moved past a read head (78), changes in magnetic field present at transition points (82) and (84) between the voids (88) and the uniformly magnetized oxide coating (16) of adjacent areas cause a current to be induced in a coil (80) of the read (78) head which current is interpreted by conventional read circuitry as being a data bit. The data inscribed by this method is not erasable by conventional means. The inventive method may be practiced upon selected portions of a medium (12) such that non-erasable data areas and conventional magnetically erasable data areas can coexist on the same medium (12).
摘要:
A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions. The innermost tracks contain redundant copies of a disk mapping table that comprises data for a media type code, a sector size code, a sector interleave code, a total track count, a reassignment area starting address, a data area starting address, a total sector count, an update count, and a reassignment table having at least room for 250 entries of three bytes each.
摘要:
A magnetic information storage medium, such as a floppy or rigid magnetic disk having a plurality of indelible grooves inscribed on a surface of the medium to function as optical servo tracks. The grooves can be in the form of a plurality of continuous or noncontinuous concentric circles. The grooves can also be a continuous spiral or a plurality of continuous concentric circles having non-constant widths and/or depths.
摘要:
A magnetic medium including a physical reference feature for conveying positional information to a magnetic read/write head. The reference feature is made by indelibly marking a pattern on a surface of the medium such as by inscribing the metal oxide coating on the medium surface or by chemical etching or photolithography of the surface. Magnetic data is written on the surface of the medium and when data written on the reference feature is read, a modulated read back signal is observed which indicates the position of the reference feature. The position of the reference feature is used to direct the read/write head to track zero or to some other position on the medium surface. By using a second magnetic read/write head to write data on a second surface of the medium in response to the modulated readback signal, an electronic reference track can be written on the second surface for providing positional information to the second magnetic read/write head.
摘要:
A dual magnetic head having a first magnetic core for reading and writing very high track density floppy disks and a second magnetic core for reading and writing conventional track density floppy disks. Neither the first nor the second magnetic cores require the trim erase elements associated with prior art magnetic cores for use with floppy disks. When writing on conventional track density floppy disks, separation between data tracks is achieved by erasing a circular region on a first rotation of the floppy disk, erasing a second region, separated from the first region by a small gap, on a second rotation of the floppy disk, and writing data during a third rotation of the floppy disk centered about the small gap. With very high density floppy disks, data is written directly between optical servo tracks on the floppy disk without use of the two erase steps.
摘要:
A magnetic information storage medium, such as a floppy or rigid magnetic disk, and an apparatus and method for inscribing a plurality of indelible grooves in a surface of the medium to function as optical servo tracks. The grooves can be in the form of a plurality of continuous or noncontinuous concentric circles. The grooves can also be a continuous spiral or a plurality of continuous concentric circles having non-constant widths and/or depths. The apparatus comprises a platen and drive motor for rotating the medium, an argon ion laser light source for generating a beam of light, optical components for directing the beam of light to a beam focusing carriage and a microcomputer for controlling the apparatus. The method involves rotating the medium under the focused light beam to inscribe the grooves on the surface of the medium. Optical track densities greater than 1000 tracks per inch can be obtained with the method.
摘要:
A diskette comprising a jacket, a liner material disposed within said jacket, a flat circular media having a magnetic coating on both sides disposed within said liner material, a hub attached at the center of said media, a plurality of servo grooves on at least one of said sides of said media that have stitched patterns that will alternate on-and-off at twenty kilohertz in the presence of a constant, unmodulated light source. The diskette is magnetically formatted with reference and data tracks recorded in such a way that extremely accurate position determinations can be made by looking at the analog amplitude of the detected tracks and comparing them at different head positions. The innermost tracks contain redundant copies of a disk mapping table that comprises data for a media type code, a sector size code, a sector interleave code, a total track count, a reassignment area starting address, a data area starting address, a total sector count, an update count, and a reassignment table having at least room for 250 entries of three bytes each.
摘要:
A carriage assembly for use with high track density flexible magnetic disk drive systems that comprises a base carriage, which supports a permanent magnet, driven by a stepper motor used to achieve course positioning of the carriage assembly. A fine position acutator is attached to the base carriage by a pair of flexible metal strips that permit movement of the actuator relative to the base carriage for fine positioning of a pair of magnetic heads. The fine position actuator comprises a voice coil bobbin, an upper arm which supports an upper magnetic read/write head, a lower arm which supports a lower magnetic read/write head and a hinge which connects the upper and lower arms. An optical servo tracking assembly mounted on the actuator senses optical servo tracking information on a surface of a magnetic disk and generates a signal which activates the voice coil bobbin causing movement of the actuator relative to the base carriage. The materials used in the upper and lower arms and in the hinge are chosen so as to nullify the effects of thermal and hygroscopic expansion.
摘要:
An apparatus and method for droplet steering is disclosed herein. A throated structure having a nozzle defines a converging throat with an inlet and an outlet and a vectored fluid stream directed therethrough. The fluid stream is driven through the system via a vacuum pump. As the fluid approaches the outlet, its velocity increases and is drawn away from the nozzle through a connecting channel. As a droplet is ejected from a liquid therebelow, it will have a first trajectory until it is introduced to the high velocity fluid stream at the perimeter of the interior walls of the nozzle. The fluid accordingly steers the momentum of the droplet such that it obtains a second or corrected trajectory. Alternative variations include an electrically chargeable member, e.g., a pin, positionable to be in apposition to the outlet and capillary tubes for controlling the ejection surface of the pool of source fluid.