Patents Represented by Attorney Warren R. Bovee
  • Patent number: 5216543
    Abstract: The present invention relates to an apparatus and method for patterning areas of a radiation absorbent film material. In the preferred embodiment, the film material is at least partially electrically conductive. The radiation is focused onto the film by a lenticular lens having a plurality of optically active elements to provide a radiation pattern on the film and remove or displace portions of the film to form a corresponding pattern, preferably a conductive pattern. The film may have one or more layers or regions, but at least one region must be radiation absorbent in order to allow the formation of patterns in the film in accordance with the present invention. The areas of the film affected by the phenomenon of radiation absorption are non-conductive voids which may separate the film into a plurality of conductive grid lines whereby the film is useful with a conductive lens film to increase the apparent efficiency of a photovoltaic cell.
    Type: Grant
    Filed: March 4, 1987
    Date of Patent: June 1, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Clyde D. Calhoun
  • Patent number: 5212388
    Abstract: A method and apparatus for analyzing tracking errors in magnetic tape. The apparatus and method allow for distinguishing between those errors in track configuration due to rotational errors (i.e., errors deriving from rotation of the head wheel of a recording and/or reading machine) and errors in track configuration due to other sources of error. An apparatus useful to practice the method holds a magnetic tape in a condition useful for examining the magnetic tape to measure the configuration of recorded tracks on the recording surface of the tape. The apparatus includes means for applying and maintaining a selected tension to the longitudinal and cross-web axes of the tape, a planar measuring surface having X and Y measuring scales allowing for measurement of distances between selected points on the recording surface of the tape, and a microscope or other sensing device for examining the recording surface.
    Type: Grant
    Filed: May 1, 1992
    Date of Patent: May 18, 1993
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Valentin M. Izraelev
  • Patent number: 5158834
    Abstract: A magneto optic recording medium comprising a substrate, an amorphous magnetizable rare earth-transition metal alloy layer, a transparent dielectric layer on at least one side of the magnetizable layer, and a reflective surface located to reflect light through the magnetizable alloy layer. The dielectric layer is comprised of silicon carbide of the formula SiC.sub.x, wherein x, the molar ratio of carbon to silicon, is greater than 1. The dielectric layer is preferably deposited by direct current magnetron sputtering at low argon partial pressure from an electrically conductive mixture of silicon carbide and carbon. The medium exhibits similar or improved characteristics over media constructed with present dielectrics, for example, silicon suboxide (SiO.sub.y, y<2).
    Type: Grant
    Filed: May 25, 1989
    Date of Patent: October 27, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Arnold W. Funkenbusch
  • Patent number: 5106437
    Abstract: A conformable electromagnetic radiation suppression cover comprising one or more absorbing material(s) and a sealant. The cover conforms to the shape of a reflecting structure due to forces internal to the absorbing material(s) when the cover is subjected to an agent external to the cover. The absorber comprises dissipative particles bound in a conformable polymeric binder. The sealant is positioned to seal the conformable cover to the reflecting structure, and provides environmental protection to the structure and preferably better adhesion between the cover and the structure. In a preferred embodiment, the volume of the cover is varied before shrinkage to produce a cover thickness in the direction of incident radiation, as measured after shrinkage, which produces a preselected resonant frequency for the cover. The cover may include a conductive surface, such as a metallic foil. Impedance matching materials are preferred but not required.
    Type: Grant
    Filed: February 24, 1989
    Date of Patent: April 21, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Felix P. Lau, Donald M. Yenni, Jr., Ronald W. Seemann, Richard J. Kuo
  • Patent number: 5087532
    Abstract: A magneto-optic recording medium records data in a single, direct-overwrite step. The medium includes a magneto-optical storage layer and a magnetic biasing layer disposed in selected heat conductive relationship with the storage layer. The first magnetic field is generated externally of the storage layer at a first energy level of a laser to set the magnetic orientation of domains at the storage layer. At a second energy level of the laser, which is higher than the first energy level, the magnetic biasing layer provides a second magnetic field greater than the first magnetic field for setting the magnetic orientation of domains in the storage layer.
    Type: Grant
    Filed: August 1, 1989
    Date of Patent: February 11, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: William A. Challener, IV
  • Patent number: 5085931
    Abstract: An electromagnetic radiation absorber is formed by dispersing into a dielectric binder acicular magnetic metallic filaments with an average length of about 10 micron or less, diameters of 0.1 micron or more, and aspect (length/diameter) ratios between 10:1 and 50:1. Preferably the average length is about 5 micron, the aspect ratios are between 10:1 and 25:1, and the dielectric binder is polymeric. The volume fraction of the filaments may be lower than 35% of the total and still provide satisfactory absorption. An absorbing paint is formed by dissolving the absorber in a base liquid. The absorber or absorbing paint may be applied to a conductive surface, such as a metallic wire, plate or foil. Impedance matching materials are preferred but not required.
    Type: Grant
    Filed: July 3, 1990
    Date of Patent: February 4, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Charles E. Boyer, III, Eric J. Borchers, Richard J. Kuo, Charles D. Hoyle
  • Patent number: 4964945
    Abstract: A method of providing patterned, thin-film materials on flexible substrates by depositing a first, etchable, integral mask onto a substrate, depositing a second pattern material over the mask region and then removing the mask, such as by etching. Patterned films useful as printed circuits and the like can be prepared by this method. In an alternate embodiment, patterned particles can be prepared for dispersion in a vehicle or matrix using the described process.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: October 23, 1990
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Clyde D. Calhoun
  • Patent number: 4867937
    Abstract: The invention provides a two-step process for increasing the modulus of a film in a desired direction, by drawing the film at between about 10.degree. C. above T.sub.g and 40.degree. C. below T.sub.m at a draw ratio of between 1.05 and 5.5 and then drawing the film in the same direction at between about 5.degree. C. and 35.degree. C. below T.sub.m at a draw ratio of between about 1.05 and 2.5.
    Type: Grant
    Filed: February 17, 1987
    Date of Patent: September 19, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Hin-Mo Li, Fred J. Roska
  • Patent number: 4839765
    Abstract: Prior magnetic recording diskettes have a wiping fabric, edges of which register with edges of jacket openings, thus involving a hazard of loose fibers. In the novel diskette, the edges of the wiping fabric are out of registry with the edges of the jacket openings. This not only avoids the hazard of loose fibers, but a die with which the jacket is cut remains usefully sharp for at least twice as long as it would if used to die-cut a composite of the jacket material and fabric as in the prior art. Also, the punched-out pieces of jacket material are uncontaminated by fabric and so can be reused as scrap. Preferably, the wiping fabric is separated along the line at which the jacket blank is centrally folded to form an envelope for a recording disk. By eliminating fabric at the central jacket fold, surprisingly lower temperature has been necessary to form the fold, thus eliminating distortions in the jacket at the central fold.
    Type: Grant
    Filed: February 24, 1986
    Date of Patent: June 13, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Hung Q. Lam
  • Patent number: 4833019
    Abstract: The invention provides a magnetic recording tape having a substantial increase in electromagnetic and head cleaning capabilities comprising a thin magnetic layer carried on a non-magnetic support film, the film having a ratio of Young's modulus in the longitudinal direction to Young's modulus in the transverse direction sufficiently low, typically between about 0.3 and 0.5, to provide a tape with the improved properties.
    Type: Grant
    Filed: February 17, 1987
    Date of Patent: May 23, 1989
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Nat J. Suwarnasarn
  • Patent number: 4778714
    Abstract: Magnetic recording tape is suitable for data recording mechanisms equipped with brass or other soft heads when its magnetizable layer is based on ferromagnetic iron oxide particles and contains titanium dioxide or other soft head cleaning agent which has a hardness approximating or slightly exceeding that of the iron oxide. The magnetizable layer preferably is free from, but may also contain unusually small amounts of hard head cleaning agent such as alumina.
    Type: Grant
    Filed: October 11, 1985
    Date of Patent: October 18, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Woolley, Karen M., Chong-Yong Kim, Arthur J. Ellsworth
  • Patent number: 4745508
    Abstract: When a supply tape guide of a VHS or Betamax videocassette is plastic rather than the usual stainless steel, equal or better performance is attained when the plastic is a blend of acetal copolymer and a small proportion of lubricant and anti-static agent. The same plastic may be used for either or both of the supply sleeve and the supply pin, and both can be molded of that plastic as a single piece.
    Type: Grant
    Filed: November 13, 1985
    Date of Patent: May 17, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Dale T. Tollefson
  • Patent number: 4743490
    Abstract: Some prior magnetic recording tapes have a backside layer of electrically conductive particles and friction-imparting nonmagnetic particles in a nonmagnetic binder. The novel tape differs in that the nonmagnetic particles are replaced by high-H.sub.c ferromagnetic particles, onto which may be recorded a distinctive magnetic pattern. This provides a "magnetic watermark" that should protect recordings from being counterfeited, because if one were to copy a recording onto ordinary magnetic recording tape, the copy would lack the "watermark". This should inhibit unauthorized copying of video recordings such as motion pictures.
    Type: Grant
    Filed: February 24, 1986
    Date of Patent: May 10, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Richard E. Fayling
  • Patent number: 4702561
    Abstract: N-substituted anthraquinones in which the substituent group is at least partially cyclic, either cyclohexyl or aromatic, and including anils of 1,4- and 1,8-diaminoanthraquinone with p-alkyl- and p-alkoxybenzaldehyde, are pleochroic and form guest-host combinations with dielectrically positive anisotropic nematic liquid crystals. These combinations are of value in electro-optical display devices.
    Type: Grant
    Filed: August 28, 1979
    Date of Patent: October 27, 1987
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: William A. Huffman
  • Patent number: 4664664
    Abstract: Ballistic projectiles for subsonic propulsion having a helically twisted body portion nad a tapered nose portion and having an apparent density of up to 5 g/cm.sup.3. The projectiles can be propelled through barrels having a complementary barrel without objectionable fouling.
    Type: Grant
    Filed: September 4, 1985
    Date of Patent: May 12, 1987
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: James F. Drake, Jr.
  • Patent number: 4539816
    Abstract: The present invention relates to the recovery of heat and/or condensable liquid from a gaseous environment utilizing an open cycle heat pump system. The open cycle heat pump system is employed to alter the temperature of a gas by compression, expansion, heat exchange, and combinations thereof, to condense selected vapors carried in the gaseous environment for removal from the gas. The open cycle heat pump system can also be used to extract the heat from a gas for use as desired.
    Type: Grant
    Filed: January 24, 1983
    Date of Patent: September 10, 1985
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Bryce J. Fox
  • Patent number: 4513073
    Abstract: The present invention relates to a photoconductive element comprising a photoconductive layer and one or more blocking layers adjacent thereto and having space charge layers interposed between the photoconductive layer and the blocking layers to increase the voltage acceptance potential of the photoconductive element.
    Type: Grant
    Filed: August 18, 1983
    Date of Patent: April 23, 1985
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Frank R. Jeffrey, III, James R. Shirck
  • Patent number: 4480393
    Abstract: Vapor recovery system comprising vapor source, vapor concentrating system and refrigeration condensation system. Method comprises accumulating condensable vapor in vapor accumulator, and subsequently removing vapor from accumulator using carrier gas to provide concentrated carrier gas stream. Vapor in carrier gas is condensed by refrigeration condensation means.
    Type: Grant
    Filed: June 15, 1981
    Date of Patent: November 6, 1984
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Leslie R. Flink, Bryce J. Fox, Mary K. Witzel
  • Patent number: 4379804
    Abstract: Composite, liquid-sorbent media which can be applied to various substrates to provide improved liquid-sorbent materials. The composite media comprise a liquid-sorbent underlayer and, overlying said underlayer, a liquid-permeable surface layer, the liquid sorptivity of said underlayer being greater than the liquid sorptivity of said surface layer. Transparent sheets having the liquid-sorbent composite media coated on the surface are described as a preferred embodiment of the invention.
    Type: Grant
    Filed: September 17, 1980
    Date of Patent: April 12, 1983
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: John F. Eisele, Elizabeth A. Mercer
  • Patent number: D291799
    Type: Grant
    Filed: April 26, 1985
    Date of Patent: September 8, 1987
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Anne L. Marshall, Michael S. Joss