Patents Assigned to Memorex Corporation
  • Patent number: 4880180
    Abstract: A reel for magnetic recording tape having a hub with flange attachment areas and a pair of clear plastic flanges, each having contact surfaces complementary to the hub attachment areas, the contact surfaces each having a pair of radially spaced circumferential ridges which serve as energy directors to ultrasonically weld the flanges to the hub and which contain adhesive within the annular region between the ridges to secure the flanges to the hub and to prevent eventual contamination of the tape on the reel due to migration of the adhesive.
    Type: Grant
    Filed: July 25, 1988
    Date of Patent: November 14, 1989
    Assignee: Memorex Corporation
    Inventor: Henry Adair
  • Patent number: 4861655
    Abstract: A magnetic recording medium comprises a substrate coated with a magnetic layer comprising a magnetic powder and a binder comprising an urethane resin and a vinyl chloride maleic acid copolymer having no maleic acid component and at least no more than about 0.5 wt. %.
    Type: Grant
    Filed: September 8, 1986
    Date of Patent: August 29, 1989
    Assignee: Memorex Corporation
    Inventor: Dennis W. Karle
  • Patent number: 4822637
    Abstract: Fabrication of magnetic recording media having a coating containing harsh pigment like CrO.sub.2 particles and adapted for frequent contact with a head, with good durability, abrasivity, etc., accommodated by using a lubricant system including a fluoro-silicone oil and a compatible fatty-acid-ester like butoxy ethyl stearate.
    Type: Grant
    Filed: November 7, 1986
    Date of Patent: April 18, 1989
    Assignee: Memorex Corporation
    Inventors: Fred Chi-Tat Chung, Ross P. Clark
  • Patent number: 4736845
    Abstract: Described are devices for securing a computer tape reel to an associated surrounding "wrap" where a T-sponge is inserted as an "inertial brake/hold down" between reel and wrap.
    Type: Grant
    Filed: November 18, 1985
    Date of Patent: April 12, 1988
    Assignee: Memorex Corporation
    Inventors: Michael Balderas, Ross P. Clark, Elsworth L. Urquhart
  • Patent number: 4686146
    Abstract: A novel resinous binder composition is disclosed for a magnetic recording tape or like media. Magnetic particles are dispersed within a resinous matrix having both a "hard" and a "soft" component. The "hard" component is fabricated by exposing a resin capable of being cured by electron beam irradiation.The magnetic recording media coating is very apt for use with harsh pigment like CrO.sub.2 particles and is adapted for frequent contact with a head, being adapted to exhibit good durability, abrasivity, etc. by virtue of using a lubricant system including a fluoro-silicone oil and a compatible fatty-acid-ester like butoxy ethyl stearate.
    Type: Grant
    Filed: February 18, 1986
    Date of Patent: August 11, 1987
    Assignee: Memorex Corporation
    Inventors: Dennis W. Karle, Zie A. Payne, Fred C. Chung, Ross P. Clark
  • Patent number: 4670806
    Abstract: A slider for flying a magnetic head on a fluid bearing above moving magnetic recording media is disclosed in which a fluid bearing surface includes a generally planar fluid support surface extending generally transverse to the direction of movement of the media, a ramped leading edge and a cavity having a generally spherical surface formed in the fluid support surface and spaced from the leading edge thereof. A method of making such a slider is also disclosed.
    Type: Grant
    Filed: March 14, 1980
    Date of Patent: June 2, 1987
    Assignee: Memorex Corporation
    Inventor: Sanjoy Ghose
  • Patent number: 4659627
    Abstract: Magnetic recording media having a coating containing harsh pigment like CrO.sub.2 particles and adapted for frequent contact with a head, with good durability, abrasivity, etc., accommodated by using a lubricant system including a fluoro-silicone oil and a compatible fatty-acid-ester like butoxy ethyl stearate.
    Type: Grant
    Filed: October 17, 1984
    Date of Patent: April 21, 1987
    Assignee: Memorex Corporation
    Inventors: Fred C. Chung, Ross P. Clark
  • Patent number: 4657816
    Abstract: Low performance ferromagnetic oxides are taught to be convertible into high performance ferromagnetic oxides with vastly improved coercivity by suspending ferromagnetic oxide particles in aqueous media, forming a layer of the first metal on the surfaces of the particles, forming a layer of second metal on the surfaces of the first metal and lastly, forming a layer of third metal on the surfaces of the second metal. The first and third metals can be the same in preferably transition metals such as cobalt. The second metal must be different than the first and third metals such as, for example, iron.
    Type: Grant
    Filed: April 19, 1982
    Date of Patent: April 14, 1987
    Assignee: Memorex Corporation
    Inventor: Mohammed Siddiq
  • Patent number: 4644641
    Abstract: Described are Delta-shaped magnetic recording "sliders", some being provided with a "back-bar" and associate "purge channel", the air bearing surface area of the sliders increasing gradually from a minimum at its nose to a maximum at its trailing edge.
    Type: Grant
    Filed: December 30, 1985
    Date of Patent: February 24, 1987
    Assignee: Memorex Corporation
    Inventor: Michael A. Verdone
  • Patent number: 4642541
    Abstract: Described is a novel technique and associated arrangement for determining the noise-free value of a system parameter (e.g., head position in a disk drive) which is time variable and (usually) has a noise component as detected. The technique involves processing the (as detected) noise-including value and passing it, plus a "Time-derivative version" thereof, through "Second Order/Summing" filter means.For instance, the technique is described as particularly useful with the "track-following servo" (part of the transducer positioning means) in a high density disk file (where track density is higher than usual) to secure superior head-displacement error values which are more noise-free. Thus, (see FIG. 4), a pair of first values V.sub.a, V.sub.b are secured by detecting motor current sense voltage V.sub.i, integrating it with respect to time and passing the result through a pair of novel "second order filter" means--one band-pass (F.sub.1), the other low-pass (F.sub.2); while also securing a third value V.sub.
    Type: Grant
    Filed: October 20, 1983
    Date of Patent: February 10, 1987
    Assignee: Memorex Corporation
    Inventor: Ashraf I. El-Sadi
  • Patent number: 4616277
    Abstract: Seek drive forces coupled between head actuators in a magnetic disk storage system employing separately controllable head actuators are prevented from affecting reliable head actuator operation. For this purpose a compensating signal is derived proportional to the driving current employed in performing an actuator seek operation. This compensating signal is fed forward into the drive circuit of the other actuator so as to cause this other actuator to begin moving its heads in a direction opposite to that which would be caused by the later arriving coupled drive forces, thereby making it possible to prevent driving forces coupled between actuators from deleteriously interferring with reliable actuator operation.
    Type: Grant
    Filed: June 15, 1984
    Date of Patent: October 7, 1986
    Assignee: Memorex Corporation
    Inventor: Eugenio Berti
  • Patent number: 4612586
    Abstract: A method for measuring bit shift, timing asymmetry and other characteristics indicative of the performance of a magnetic storage system, particularly for a system employing a thin-film magnetic head. In a preferred embodiment, complementary patterns are written many times around a circular track of a magnetic disk, each pattern including relatively closely spaced magnetic transitions as well as relatively widely spaced magnetic transitions. The relatively widely spaced transitions are chosen so as to be substantially unaffected by any other transitions. Measurements are made with reference to these widely spaced transitions and averaged for the many patterns recorded in the track so as to rapidly provide highly reliable measurements indicative of system performance.
    Type: Grant
    Filed: June 5, 1984
    Date of Patent: September 16, 1986
    Assignee: Memorex Corporation
    Inventors: Frank J. Sordello, Andrew M. Rose
  • Patent number: 4612517
    Abstract: Disclosed is equipment for testing a magnetic recording head; comprising a circuit which generates a test signal simulating what the head under test would generate.
    Type: Grant
    Filed: May 23, 1984
    Date of Patent: September 16, 1986
    Assignee: Memorex Corporation
    Inventor: Ronald H. Wagner
  • Patent number: 4587714
    Abstract: A disc drive arrangement including RW head actuator driven by an improved voice coil motor, having ceramic back-magnets which are subdivided to give improved magnetic characteristics and operation (increased working flux and an increase in efficiency and effective power acceleration for given current--e.g., thus decreasing "access time").
    Type: Grant
    Filed: January 3, 1984
    Date of Patent: May 13, 1986
    Assignee: Memorex Corporation
    Inventor: Frank I. Morris
  • Patent number: 4581664
    Abstract: A disk storage system is disclosed comprising a rotatable disk, a cooperating magnetic head, positioning apparatus for positioning the head at different radial positions of the disk for reading and/or writing data on the disk, a baseplate for supporting the above, and control circuitry for preventing oscillation build-up in the baseplate from deleteriously interfering with system performance. The control circuitry is constructed and arranged to control the timing of head positioning operations so as to inhibit the reinforcement of baseplate oscillations.
    Type: Grant
    Filed: September 21, 1983
    Date of Patent: April 8, 1986
    Assignee: Memorex Corporation
    Inventors: Frank J. Sordello, Andrew M. Rose
  • Patent number: 4577244
    Abstract: Described is a novel technique and associated arrangement for determining the noise-free value of a system parameter (e.g., head position in a disk drive) which is time variable and (usually) has a noise component as detected. The technique involves processing the (as detected) noise-including value and passing it through "Second Order/Summing" filter means.For instance, the technique is described as particularly useful with the "track-following servo" (part of the transducer positioning means) in a high density disk file (where track density is higher than usual) to secure superior head-displacement error values which are more noise-free. Thus, (see FIG. 4), a pair of first values V.sub.a, V.sub.b are secured by detecting motor current sense voltage V.sub.i, integrating it with respect to time and passing the result through a pair of novel "second order filter" means--one hand-pass (F.sub.1), the other low-pass (F.sub.2); while also securing a third value V.sub.
    Type: Grant
    Filed: December 12, 1983
    Date of Patent: March 18, 1986
    Assignee: Memorex Corporation
    Inventor: Ashraf I. El-Sadi
  • Patent number: 4556921
    Abstract: An apparatus to improve the positioning accuracy of an actuator in a disc system. The apparatus provides for accelerating and braking the actuator at appropriate times during positioning operations in order to accurately position the actuator at a selected track on the disc. In addition, in order to maintain positioning accuracy in the presence of run-out, provision is made for detecting the occurrence of run-out by comparing positioning accuracy at spaced time intervals and blocking actuator braking at those times when it would be counter-productive to positioning accuracy.
    Type: Grant
    Filed: June 30, 1983
    Date of Patent: December 3, 1985
    Assignee: Memorex Corporation
    Inventor: Andrew M. Rose
  • Patent number: 4553181
    Abstract: Damaging head crashes are prevented in a disk drive system by providing a specially chosen RC network between the head position control servo and the head actuator. The values of the RC network are chosen in conjunction with the servo output voltage so that, without detracting from head access time, the maximum head velocity will be limited to a value which will prevent damaging head crashes even when a fault occurs in the system.
    Type: Grant
    Filed: July 12, 1983
    Date of Patent: November 12, 1985
    Assignee: Memorex Corporation
    Inventor: Eugenio Berti
  • Patent number: 4547534
    Abstract: The present invention is a method to disperse fine solids in a resin binder matrix by use of a sand mill having non-metallic discs and containing zirconium oxide milling media. The method of the invention will disperse the fine solids without reduction of the size of the fine solids or contamination to the dispersion by fines of the zirconium oxide milling media.
    Type: Grant
    Filed: August 3, 1984
    Date of Patent: October 15, 1985
    Assignee: Memorex Corporation
    Inventors: Leo di Ricco, Edward Schnee, Zorro Stefanini, Duncan W. Frew
  • Patent number: 4517616
    Abstract: The subject invention relates to the fabrication of metal oxide patterns on a substrate adapted for use with thin film magnetic heads. The metal oxide pattern has a precisely defined geometry including nearly vertical side walls, for minimizing read/write errors. In addition, a filler material formed from a non-magnetic, non-metallic compound is provided on the substrate in a pattern complimentary to the metal oxide pattern. In accordance with the subject invention, the top surface of the metal oxide pattern and the filler material are co-planar. By this arrangement, subsequent layers may be uniformly deposited without discontinuities. The subject method includes a plurality of distinct masking and etching steps in order to achieve the desired result.
    Type: Grant
    Filed: March 28, 1983
    Date of Patent: May 14, 1985
    Assignee: Memorex Corporation
    Inventor: Peter G. Bischoff