Patents by Inventor Sankar B. Narayan

Sankar B. Narayan 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: 5356664
    Abstract: A method of inhibiting algae growth on an asphalt shingle surface exposed to varying humidity using a blend of copper-containing algae-resistant granules and non-algae-resistant granules. The copper-containing algae-resistant granules comprise a substrate granule having at least one inner ceramic coating layer comprising cuprous oxide and a seal coating having a thickness covering the inner layer and which is at time t.sub.o devoid of copper.
    Type: Grant
    Filed: June 11, 1993
    Date of Patent: October 18, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Sankar B. Narayan, William T. Fay, Billy L. George, Christine A. Sobon, Mark H. Kayser
  • Patent number: 4937691
    Abstract: A drive for a recording disk includes a drive motor and a head transport mounted on a chassis which has a coefficient of expansion equal to that of the disk to reduce tracking errors caused by differential expansion of the chassis and the disk due to environmental changes.
    Type: Grant
    Filed: April 22, 1988
    Date of Patent: June 26, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Sankar B. Narayan, Felix P. Lau, Takehiko Saito
  • Patent number: 4729805
    Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice during manufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
    Type: Grant
    Filed: August 11, 1986
    Date of Patent: March 8, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson
  • Patent number: 4623570
    Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice duringmanufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
    Type: Grant
    Filed: March 14, 1985
    Date of Patent: November 18, 1986
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson
  • Patent number: RE33187
    Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice .[.duringmanufacture.]. .Iadd.during manufacture .Iaddend.to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: March 27, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson
  • Patent number: RE34765
    Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice during manufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
    Type: Grant
    Filed: November 2, 1988
    Date of Patent: October 25, 1994
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Jerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson