Patents Represented by Attorney Nathan N. Kallman

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  • Roll balance sub-ambient pressure air bearing slider
    Patent number: 5685645
    Abstract: A sub-ambient pressure air bearing slider is configured with longitudinal air-bearing rails that have angular side recesses near the trailing end of the slider. Sub-ambient pressure regions formed within the side recesses during disk operation oppose the asymmetrical lift forces which cause undesirable roll. The slider provides improved roll and flying height characteristics.
    Type: Grant
    Filed: August 13, 1996
    Date of Patent: November 11, 1997
    Assignee: Read-Rite Corporation
    Inventors: Daniel A. Nepela, Ciuter Chang
  • Optics method and fixture for assembling and testing a magnetic head
    Patent number: 5680213
    Abstract: A method for optically testing a magnetic head having a slider and a suspension includes the steps of separately mounting the slider and the suspension in a test fixture. The slider is mounted in a cage and positioned relative to the suspension. The slider and the suspension are then tacked temporarily in place with a suitable adhesive. The magnetic head is flown over a glass disk and is illuminated through the glass disk with either a monochromatic or a polychromatic light beam. The operator then views the magnetic head through the glass disk with a microscope and observes the resulting diffraction interference patterns, which include bright and dark or colored bands. The operator analyzes the alignment of these bands, determines the pitch and roll errors of the magnetic head, and repositions either the slider or the suspension to correct for these errors.
    Type: Grant
    Filed: February 7, 1997
    Date of Patent: October 21, 1997
    Assignee: Read-Rite Corporation
    Inventors: Michael D. Hunsaker, Barry W. Darr
  • Noise detecting apparatus for magnetic heads
    Patent number: 5668477
    Abstract: A testing apparatus for detecting popcorn noise in magnetic heads comprises a fully integrated testing system which includes an analog circuit portion and a digital circuit portion. The analog circuit portion is implemented to interface with a magnetic head while the digital circuit portion is designed to store the testing sequence, analyze the testing data, control and execute the testing routines. The testing apparatus is designed for production environments where testing data are required instantaneously as feedback for production process monitoring.
    Type: Grant
    Filed: February 16, 1995
    Date of Patent: September 16, 1997
    Assignee: Read-Rite Corporation
    Inventors: Mostafa Mahmoudian, Jagdeep S. Buttar, Oleg A. Gergel, Neil Motiska
  • Stabilization of giant magnetoresistive transducers
    Patent number: 5657191
    Abstract: A magnetic transducer employing giant magnetoresistance (GMR) has alternating ferromagnetic layers and spacer layers, the spacer layers having either different material compositions or different thicknesses across their widths to produce variations in the coupling between adjacent ferromagnetic layers across their widths. Longitudinal stabilization of the multi-layer GMR sensor is achieved by the use of exchange coupling layers on the top and/or bottom of the sensor edge-track regions.
    Type: Grant
    Filed: September 18, 1995
    Date of Patent: August 12, 1997
    Assignee: Read-Rite Corporation
    Inventor: Samuel W. Yuan
  • Head arm assembly having an integral arm with a portion encased in a rigid molded material
    Patent number: 5654851
    Abstract: A head arm assembly for use in a disk file includes an elongated thin element having one end supporting a head gimbal assembly (HGA) which is biased toward a recording surface of a magnetic disk during normal operation. The element is preferably made of a metal that has a flex characteristic predetermined in accordance with selected specifications of the head arm. The opposite end of the element is provided with an etched out opening for a pivot bearing and is encased in a moldable material having a different and more rigid flex characteristic. The head arm assembly is provided with the required two flex characteristics for successful operation but does not require the precise joining of two separate and distinct metal elements.
    Type: Grant
    Filed: July 21, 1995
    Date of Patent: August 5, 1997
    Assignee: Read-Rite Corporation
    Inventors: Larry E. Tucker, William P. Heist
  • Magnetoresistive read transducer with partially abutted junctions
    Patent number: 5646805
    Abstract: A magnetoresistive transducer is formed with a trilayer structure including a soft adjacent magnetic layer (SAL), a spacer layer and a magnetoresistive (MR) sensor element. The SAL and part of the spacer layer extend continuously across the transducer structure. The MR sensor element has end portions that partially abut hard permanent magnetic (PM) films and partially abut conductive leads formed over the PM films. The transducer structure minimizes the problem of electrical shorting and achieves significant improvements in magnetic performance of the active MR region and signal readout.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: July 8, 1997
    Assignee: Read-Rite Corporation
    Inventors: Yong Shen, Steven Clark Rudy
  • Thin film giant magnetoresistive CPP transducer with flux guide yoke structure
    Patent number: 5627704
    Abstract: A giant magnetoresistive (GMR) thin film transducer employs a pair of flux guide pole members that define a magnetic transducing gap. A GMR structure formed of a stack of multiple layers is located between spaced portions of one of the flux guide pole members and away from the transducing gap. Bias current is supplied in a CPP (current perpendicular to the plane) mode. In an alternative embodiment, a plurality of such GMR structures are connected together serially to provide a larger output signal than that obtained with a single GMR stack.
    Type: Grant
    Filed: February 12, 1996
    Date of Patent: May 6, 1997
    Assignee: Read-Rite Corporation
    Inventors: Marcos M. Lederman, Derek J. Kroes
  • Magnetic head structure with reduction of magnetic domain instability
    Patent number: 5617278
    Abstract: Boundary protrusions or kinks are integrally formed along the perimeter of a magnetic layer of a magnetic transducer for nucleating a predetermined domain pattern in the magnetic layer. These protrusions or kinks behave as domineering pinning sites for the domain walls, overriding other factors such as manufacturing tolerances or external magnetic field, for establishing a stable magnetic domain pattern. As arranged, various kinds of noise encountered during the normal operations of the transducer are significantly reduced, as the noise related problems originated from the magnetic domain instabilities in the magnetic layers are substantially curtailed.
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: April 1, 1997
    Assignee: Read-Rite Corporation
    Inventors: Shih-Cheng Cheng, Hua-Ching Tong, William C. Cain
  • Method of forming a thin film magnetic structure having ferromagnetic and antiferromagnetic layers
    Patent number: 5612098
    Abstract: A method of forming a magnetic structure having layers with different magnetization orientations provided by a common magnetic bias layer includes the steps of depositing an antiferromagnetic layer between first and second ferromagnetic layers. During the deposition of the first and second ferromagnetic layers, magnetization fields of different orientations are employed separately to induce different directions of magnetization in the first and second layers. The different directions of magnetization in the first and second layers are sustained, through the process of exchange coupling, by the interposed antiferromagnetic layer which serves as the bias layer. A magnetic structure thus fabricated, can be used as a read transducer capable of generating differential signals with common mode noise rejection, and can be used as a magnetic pole for a magnetic head with reduced Barkhausen noise.
    Type: Grant
    Filed: August 14, 1996
    Date of Patent: March 18, 1997
    Assignee: Read-Rite Corporation
    Inventors: Minshen Tan, Hua-Ching Tong, Francis H. Liu, Swie-In Tan
  • Altitude insensitive air bearing slider
    Patent number: 5606476
    Abstract: The air bearing surface of an air bearing slider is formed with first and second side rails and a central recess. The rails are configured to have an inverted U-shaped section and a connecting partial trapezoidal-type section. The U-shaped section has a base joined to two spaced legs, wherein one leg is preferably longer than the other. A continuous recess is provided between the legs of each side rail and extends from the base towards the trailing end of the slider and adjacent to the trapezoidal-type section. The slider is effectively insensitive to changes in air pressure, particularly in variations in altitude, so that a substantially constant flying height can be maintained.
    Type: Grant
    Filed: July 13, 1995
    Date of Patent: February 25, 1997
    Assignee: Read-Rite Corporation
    Inventors: Ciuter Chang, Yiao-Tee Hsia
  • Gimbal assembly of a magnetic head suspension
    Patent number: 5602699
    Abstract: A gimbal assembly of a magnetic head suspension includes a flexure having a dimple. A slider carrying a magnetic transducer is attached to the flexure and in contact with the dimple. The flexure has a polygon shape with cutouts defining a plurality of internal and external strut members. Each strut member is elongated in shape with a substantial uniform width. The flexure has a wider midsection than its end sections. When the slider flies above the disk surface over a thin air film, pivoting against the dimple, the flexure provides sufficient agility for the slider to accommodate the uneven topology of the disk surface, yet the flexure is enough stiff to resist any physical deformation that could be caused by the rapid movements of the actuator arm carrying the gimbal assembly.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: February 11, 1997
    Assignee: Read-Rite Corporation
    Inventor: Amanullah Khan
  • Alignment of magnetic poles of thin film transducer
    Patent number: 5578342
    Abstract: A process for producing a thin film magnetic head uses the upper magnetic pole as a self-aligning mask for partially trimming the lower magnetic pole, wherein the yoke and pole tip regions to be trimmed are processed by separate and distinct photolithographic steps, thereby achieving noncritical alignment in the yoke area, while maintaining critical alignment in the pole tip region which includes the transducing gap.
    Type: Grant
    Filed: July 5, 1995
    Date of Patent: November 26, 1996
    Assignee: Read-Rite Corporation
    Inventors: Ut Tran, Tai Lee, Tran Son
  • Compact read/write head having biased GMR element
    Patent number: 5576914
    Abstract: A compact read/write head is provided having a biased GMR element. Biasing of the GMR element provides distinguishable response to the rising and falling edges of a recorded pulse on an adjacent medium. It also improves the linearity of the response and helps to reduce noise.
    Type: Grant
    Filed: November 14, 1994
    Date of Patent: November 19, 1996
    Assignee: Read-Rite Corporation
    Inventors: Robert E. Rottmayer, Jian-Gang Zhu
  • Negative pressure air bearing slider
    Patent number: 5568981
    Abstract: A negative pressure air bearing slider is provided with side rails, a central negative pressure cavity between the side rails and one or more relief vents at the leading edge of the slider. The side rails extend fully or partially from tapered regions at the leading edge of the slider to the trailing edge of the slider. Air bearing pads disposed adjacent to the front tapered regions and/or the slider trailing edge may be configured with the side rails. By virtue of the slider design, variations in flying height and roll are minimized.
    Type: Grant
    Filed: April 10, 1995
    Date of Patent: October 29, 1996
    Assignee: Read-Rite Corporation
    Inventors: Daniel A. Nepela, Ciuter Chang, Yiao-Tee Hsia, Rajendra Bhadra
  • Magnetic head suspension
    Patent number: 5568332
    Abstract: A magnetic head suspension assembly is fabricated with a flexure that is formed with a U-shaped finger surrounded by a cutout at the front end of the flexure. A load dimple is provided on the flexure. The flexure supports an air bearing slider that pitches and rolls relative to a disk surface and is subject to lateral displacement during operation in a disk drive. The flexure is formed with primary stabilizer sections and secondary stabilizer arms which reduce pitch and roll stiffnesses while increasing lateral stiffness, thereby maintaining a substantially constant slider flying height.
    Type: Grant
    Filed: December 22, 1994
    Date of Patent: October 22, 1996
    Assignee: Read-Rite Corporation
    Inventor: Amanullah Khan
  • Nipple for a vehicle washer pump
    Patent number: 5538295
    Abstract: This invention relates to nipples, an inlet nipple 2 and an outlet nipple 3, for a washer pump to squirt washer fluid onto a windshield of a vehicle. The respective nipples 2, 3 include a first connecting portion 4, 4a and a second connecting portion 5, 5a so that two kinds of conduits 8, 8a having different inner diameters can be selectively connected to the first connecting portion 4, 4a or the second connecting portion 5, 5a. The connecting portions include an annular rib 6, 7 on their peripheries to seal the clearance between the nipples 2, 3 and the respective conduits 8, 8a connected to them.
    Type: Grant
    Filed: August 22, 1994
    Date of Patent: July 23, 1996
    Assignee: Dong Yang Industrial Company, Ltd.
    Inventor: In K. Kim
  • Disk drive apparatus having up and down head supsensions independently loadable into a space between immediately adjacent disks
    Patent number: 5535074
    Abstract: The headstack of a disk drive is formed with separate sections, each of which supports a plurality of head suspensions. In one embodiment, the sections are blocks on which pairs of head suspensions having UP and DOWN facing sliders are mounted. The blocks are individually positioned and aligned relative to a disk stack. In a second embodiment, head suspensions are supported by a pair of modules. A first module supports suspensions with UP head sliders and a second module supports suspensions with DOWN head sliders. The modules interlock so that an alternating arrangement of UP and DOWN heads result. By use of a comb-like head loading tool, the suspensions that carry the head sliders are spaced and loaded to respective disk surfaces.
    Type: Grant
    Filed: January 9, 1995
    Date of Patent: July 9, 1996
    Assignee: Read-Rite Corporation
    Inventor: Chak M. Leung
  • Method of producing exchange coupled magnetic thin films with post-deposition annealing
    Patent number: 5529814
    Abstract: Exchange coupled magnetic thin films are produced by depositing an antiferromagnetic layer, followed by deposition of a layer of ferromagnetic material on the antiferromagnetic layer. The composite antiferromagnetic/ferromagnetic structure is then annealed at an elevated temperature for a predetermined length of time. This process results in considerably higher exchange coupling fields than obtainable before. Alternatively, the antiferromagnetic layer may be annealed prior to deposition of the ferromagnetic layer.
    Type: Grant
    Filed: October 19, 1995
    Date of Patent: June 25, 1996
    Assignee: Read-Rite Corporation
    Inventors: Minshen Tan, Hua-Ching Tong, Swie-In Tan
  • Wiper blade unit for a vehicle windshield
    Patent number: D370653
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: June 11, 1996
    Assignee: Dong Yang Industrial Co., Ltd.
    Inventor: In K. Kim
  • Wiper blade unit for a vehicle windshield
    Patent number: D370654
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: June 11, 1996
    Assignee: Dong Yang Industrial Co., Ltd
    Inventor: In K. Kim