Patents by Inventor Durga Ravipati

Durga Ravipati has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6445536
    Abstract: A thin film head apparatus and method for forming such a thin film head. In one approach, the present invention recites forming a cavity in a dielectric layer. Next, a layer of high magnetic field saturation (HBsat) material is sputter-deposited over the dielectric layer such that the HBsat material is deposited into the cavity formed in the dielectric layer. The cavity in the dielectric layer functions as a mold or “stencil” for the HBsat material. The HBsat material deposited into the cavity is used to form the first core of a thin film head. After the formation of the first core of the thin film head, a gap layer of material is deposited above the dielectric layer and above the first core. Next, a layer of HBsat material is sputter-deposited above the gap layer of material and above the first core of the thin film head. The layer of HBsat material disposed above the gap layer of material and above the first core is used to form the second core of the thin film head.
    Type: Grant
    Filed: August 27, 1998
    Date of Patent: September 3, 2002
    Assignee: Read-Rite Corporation
    Inventors: Steven C. Rudy, Hugh C. Hiner, Lien-Chang Wang, Yong Shen, Ut Tran, Yunju Ra, Durga Ravipati
  • Patent number: 6137662
    Abstract: A magnetoresistive sensor including a magnetoresistive (MR) sensing element, a nonmagnetic layer ("spacer") contacting the magnetoresistive sensing element; a first antiferromagnetic (AFM) layer contacting the nonmagnetic layer such that the nonmagnetic layer is sandwiched between the magnetoresistive sensing element and the antiferromagnetic layer; a ferromagnetic soft adjacent layer (SAL) contacting the antiferromagnetic layer such that the antiferromagnetic layer is sandwiched between the nonmagnetic layer and the soft adjacent layer; and a second antiferromagnetic layer contacting the SAL such that the SAL is sandwiched between the first and second antiferromagnetic layers. The two antiferromagnetic layers provide a stronger pinning effect. In one embodiment of the invention, the magnetoresistive sensing element is an anisotropic magnetoresistive (AMR) sensing element comprising a soft ferromagnetic layer.
    Type: Grant
    Filed: April 7, 1998
    Date of Patent: October 24, 2000
    Assignee: Read-Rite Corporation
    Inventors: Yiming Huai, Daniel Nepela, Durga Ravipati, Marcos Lederman
  • Patent number: 5438470
    Abstract: A magnetoresistive read transducer includes a magnetoresistive (MR) layer having end regions spaced by a central active regions. A pair of hard-magnetic layers provide the longitudinal magnetic bias to the magnetoresistive layer. Each of the hard-magnetic layers is disposed in contact with one of the end regions of the magnetoresistive layer. In addition, a pair of electrical leads provide the bias current to the magnetoresistive layer. Each of the electrical leads is also disposed in contact with one of the end regions of the magnetoresistive layer. This arrangement enable the transducer of the present invention with the most optimal design. In essence, electrical current directly passes through the central active region of the magnetoresistive layer via the electrical leads as a low electrical resistance path. Magnetic flux of the longitudinal bias directly passes through the central active region of the magnetoresistive layer with a reduced probability of magnetic discontinuity.
    Type: Grant
    Filed: May 13, 1994
    Date of Patent: August 1, 1995
    Assignee: Read-Rite Corporation
    Inventors: Durga Ravipati, Yong Shen, William C. Cain
  • Patent number: 5232570
    Abstract: A hard protective material and method for forming the medium having the formula C.sub.x N.sub.y. The medium may be formed as a protective film on a magnetic recording disk in a sputtering apparatus such as a magnetron apparatus. The amount of nitrogen in the film may be affected by controlling the collisions of the sputtered material between the target and deposition substrate by controlling the bombardment of the substrate by electrons. The films exhibit properties indicative of a textured morphology on a nanoscale which enhances the retention of lubricant overcoats.
    Type: Grant
    Filed: June 28, 1991
    Date of Patent: August 3, 1993
    Assignee: Digital Equipment Corporation
    Inventors: William G. Haines, Chongwon Byun, Earl Johns, Quock Ng, Durga Ravipati, Robert M. Raymond, Gary C. Rauch