Patents Represented by Attorney William L. Botjer
  • Patent number: 6534772
    Abstract: A microchannel phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced microchannels having diameters of the order of 40 microns or less. Deposited within each of the microchannels is a multiplicity of phosphors which emit light when acted upon by radiation. The dimensions of the microchannel and the phosphors and the relationship between the microchannels and the phosphors is optimized so that the light output compares favorably with lower resolution non microchannel based scintillation screens. A photomultiplier can be integrated with the X-ray detector so as to provide an enhanced output for use with low level X-ray of for cine or fluoroscopy applications.
    Type: Grant
    Filed: October 16, 2000
    Date of Patent: March 18, 2003
    Assignee: Nanocrystal Imaging Corp.
    Inventors: Vishal Chhabra, Rameshwar Nath Bhargava, Dennis Gallagher, Samuel P. Herko, Bharati S. Kulkarni, Nikhil R. Taskar, Aleksey Yekimov
  • Patent number: 6452184
    Abstract: A composite phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced microchannels having diameters of the order of 10 microns or less. Deposited within each of the microchannels is a multiplicity of phosphors which emit light when acted upon by radiation. A photomultiplier, which may be microchannel based, is integrated with the X-ray detector so as to provide an enhanced output for use with low level X-ray of for cine or fluoroscopy applications. The walls of the microchannels and/or the substrate surfaces include dielectric stack based light reflective coatings.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: September 17, 2002
    Assignee: Nanocrystal Imaging Corp.
    Inventors: Nikhil R. Taskar, John Victor D. Veliadis, Vishal Chhabra, Bharail Kulkarni, Neeta Pandit, Rameshwar Nath Bhargava, Roger Delano
  • Patent number: 6361824
    Abstract: Methodology for providing a smooth, thin, highly reflective coating to the walls of microchannels disposed in a plate or substrate. Such plates are commonly used in image intensifiers and have more recently been used to provide high resolution X-ray imaging screens. In the process silver nitrate solution is reacted so as to provide a silver amine complex. In a first embodiment of the process, the microchannel plates are disposed vertically in a beaker and immersed, without stirring, in a solution including the silver amine complex and a reducing agent. In a second embodiment of the process, a fluid flow of filtered reactant is directed through the microchannels. In each embodiment the walls of the microchannels become plated with a highly reflective (>90%), thin (20-50nm) and smooth coating of metallic silver.
    Type: Grant
    Filed: July 31, 2000
    Date of Patent: March 26, 2002
    Assignee: Nanocrystal Imaging Corp.
    Inventors: Aleksey Yekimov, Vishal Chhabra
  • Patent number: 6300640
    Abstract: A composite phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced microchannels having diameters of the order of 10 microns or less. Deposited within each of the microchannels is a multiplicity of phosphors which emit light when acted upon by radiation. The walls of the microchannels and/or the substrate surfaces include light reflective coatings so as to reflect the light emitted by the phosphors to the light collecting devices, such as film or an electronic detector. The coatings can be either radiation transparent or filtering/attenuating depending on the particular application.
    Type: Grant
    Filed: November 20, 1998
    Date of Patent: October 9, 2001
    Assignee: Nanocrystal Imaging Corporation
    Inventors: Rameshwar Nath Bhargava, Nikhil R. Taskar, Vishal Chhabra, John Victor D. Veliadis
  • Patent number: 6289842
    Abstract: A Metal Organic Chemical Vapor Deposition (MOCVD) system particularly suitable for use at low deposition pressures and high or low temperatures. The system includes a reactor chamber having a reactant gas distribution unit (showerhead) which may be height adjustable having a temperature control chamber, for controlling the temperature of the reactants, a chamber for providing a uniform flow of carrier gas and a gas distribution chamber which includes baffling which can preclude gas phase mixing of the reactants. The gas distribution unit also includes an integral plasma generating electrode system for providing plasma enhanced deposition with controlled distribution of reactants. Also located in the reactor chamber is a temperature control unit for heating and/or cooling the wafers and a non-levitating rotating wafer carrier.
    Type: Grant
    Filed: June 18, 1999
    Date of Patent: September 18, 2001
    Assignee: Structured Materials Industries Inc.
    Inventor: Gary Steven Tompa
  • Patent number: 6236061
    Abstract: A structure and methodology for providing electronic devices comprised of semiconductor materials deposited and crystallized using a pulsed laser source on oxide and/or metal layers on polymeric and polymer composite substrates of low coefficient of thermal expansion (CTE). The present invention permits the fabrication of inexpensive yet highly efficient electronic devices, such as photovoltaic cells, on the filled substrates by the use of laser annealing techniques.
    Type: Grant
    Filed: January 8, 1999
    Date of Patent: May 22, 2001
    Inventor: Lakshaman Mahinda Walpita
  • Patent number: 6142758
    Abstract: A rotary positive displacement engine includes one or more power rotors, which are acted upon by a pressurized charge of gas, such as steam, and an annular barrier rotor geared for synchronous rotation with the power rotors. The rotors rotate within intersecting cylindrical bores in the engine housing. The power rotors have cylindrical outer surfaces from which opposed vanes extend which are acted upon by the powering charge. The barrier rotor has an outer cylindrical surface, located in close proximity to the cylindrical surface of the power rotors, and ports for delivering the powering charge to the power rotors. The barrier rotor thus forms both a charge delivery mechanism and a barrier between the exhaust ports and the expanding gas powering the engine. Located within the barrier rotor is a stator which has ports in fluid communication with the ports in the barrier rotor when the respective ports are aligned.
    Type: Grant
    Filed: June 28, 1999
    Date of Patent: November 7, 2000
    Assignee: Henry Engine Company
    Inventor: Michael Blake Taggett
  • Patent number: 6100800
    Abstract: A vehicle emergency warning system which is suitable for automatic deployment. The vehicle emergency warning system includes first and second movably joined elements bearing warning indicia. The first element may be biased upwardly so as to stand upright with the second element forming a base. The vehicle emergency warning system is compact, lightweight and may be easily moved so that it may be positioned at the front, alongside or in back of the stopped vehicle and is particularly suitable for roof mounting. The vehicle emergency warning system may be folded flat and can be readily built into a compartment in the vehicle so that it may be deployed without the need for the driver or passenger to exit the vehicle.
    Type: Grant
    Filed: December 21, 1998
    Date of Patent: August 8, 2000
    Inventor: Ali Sigari
  • Patent number: 6036886
    Abstract: A process for the production of metal oxide nanocrystals activated with a rare earth element, which are useful as phosphors. The nanocrystal oxides are produced by a micellar microemulsion process. In the process an aqueous solutions of the host and activator is prepared and added to a mixture of oil and a micelle forming surfactant and cosurfactant to form a first water in oil microemulsion. An aqueous solution of a hydroxide containing compound is added to a second mixture of oil and a micelle forming surfactant and cosurfactant to form a second water in oil microemulsion. The two microemulsions are added together which cause the micelle units to coalesce and decoalesce and to form a nanocrystalline hydroxide compound of the host and activator. The solution is washed and treated so as to remove byproducts. Thereafter the hydroxide compound is converted to an nanocrystalline activated oxide.
    Type: Grant
    Filed: July 29, 1998
    Date of Patent: March 14, 2000
    Assignee: Nanocrystals Technology L.P.
    Inventors: Vishal Chhabra, Bharati S. Kulkarni, Rameshwar Nath Bhargava
  • Patent number: 5977762
    Abstract: Apparatus and methodology for detection of lightning. The invention includes an antenna and amplifier for receiving the electrostatic and/or electromagnetic discharges of lightning and electrical noise and outputs an analog electrical signal representative of the discharge. The analog signal is applied to a threshold detection circuitry whose output is activated when the input signal rises above a predetermined level. The output of the threshold circuitry is a series of pulses of varying length. A computer or other programmable device is connected to the output of the threshold circuitry and opens an event window when the first pulse is received and determines the number of pulses received and the total duration of the pulses during the event window. The number and total duration of the pulses is compared to stored pulse signatures of lightning discharges and man made electrical noise.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: November 2, 1999
    Assignee: Mirage Lighting Technology Ltd
    Inventors: John B. Murtha, Jr., William H. Skinner, II
  • Patent number: 5952665
    Abstract: A composite phosphor screen for converting radiation, such as X-rays, into visible light. The screen includes a planar surface, which can be formed from glass, silicon or metal, which has etched therein a multiplicity of closely spaced nanochannels having diameters of the order of 5 microns or less. Deposited within each of the nanochannels is a multiplicity of nanocrystalline phosphors, having diameters of less than 100 nanometers and preferably less than 10 nanometers, which emit light when acted upon by radiation. The walls of the nanochannels are arranged to reflect the light emitted by the nanophoshors down the nanochannels to suitable light collecting device such as film or an electronic device. This minimizes light scattering and increases light collection efficiency.
    Type: Grant
    Filed: November 28, 1997
    Date of Patent: September 14, 1999
    Assignee: Nanocrystals Technology L.P.
    Inventor: Rameshwar Nath Bhargava
  • Patent number: 5838308
    Abstract: An optical touch input device comprises an array of actively addressed sensing elements (18) for sensing a light input, e.g. from a light pen, each of which comprises a capacitor (25) which is charged periodically through operation of a switch device (24) and a discharge circuit, including a photosensitive device (28) and a further switch device (27) connected across the capacitor, which circuit in operation demonstrates an optical threshold characteristic whereby the capacitor (25) is discharged in response to the sensing elements being subjected to light which is at or above a predetermined intensity level so as to discriminate from ambient light. Elements written into are determined by detecting the charge stage of their capacitors. The sensing element array can be integrated with a matrix display device with the sensing elements (18) and display elements components (12) provided on a common support using thin film technology.
    Type: Grant
    Filed: April 15, 1992
    Date of Patent: November 17, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Alan G. Knapp, John M. Shannon
  • Patent number: 5808562
    Abstract: A vehicle detector for installation on the surface of a multi-lane road, comprising at least a coaxial detector cable provided with a central conductor, a metallic cladding and a filler material between the cladding and the conductor. The coaxial detector cable comprises at least one region which is referred to as the active region and in which the filler material is mechanoelectric, and also comprises at least one adjoining region which is referred to as a neutral region and in which the filler material is neither mechanoelectric nor potentially mechanoelectric.
    Type: Grant
    Filed: September 11, 1992
    Date of Patent: September 15, 1998
    Assignee: U.S. Philips Corporation
    Inventors: Gilles Bailleul, Patrick Coville
  • Patent number: 5670753
    Abstract: The invention relates to a disc-shaped transducer (10) for a weighing system, comprising surfaces (14) which extend parallel to one another and in a direction of application of a force (F) to be measured, at least one of said surfaces being provided with a sensing element (13) for converting a force-dependent deformation into a useful signal. Transducers (10) of this kind usually exhibit a material-dependent, significant hysteresis effect which adversely affects their calibration possibilities; therefore, the transducer (10) comprises four sub-faces (21) which are formed by a centre line (17) parallel to the direction of application of the force (F) and a centre line (20) which is orthogonal thereto, at least two of said sub-faces which adjoin one another in only one point comprising a respective area of reduced cross-section or reduced thickness, so that the hysteresis can be compensated for.
    Type: Grant
    Filed: October 4, 1993
    Date of Patent: September 23, 1997
    Assignee: U.S. Philips Corporation
    Inventor: Matthias Krause
  • Patent number: 5650201
    Abstract: A process for depositing carbon nitride films on substrates or work pieces by means of plasma assisted energy controlled ion beam deposition. The process produces microscopically smooth, nearly stress free, insulating and transparent carbon nitride thin films at room (or elevated) temperature. In the process the substrate, tool or other component to be coated is placed in a vacuum chamber at room temperature and is acted upon by a source of negative carbon ions and a high flux plasma source of nitrogen radicals. The source of C.sup.- ions is hydrogen free and provides particle energies suitable for the production of films of high quality carbon nitride. The source of the nitrogen flux provides a high density of nitrogen radicals to interact with the C.sup.- ion beam and coat the substrate with carbon nitride. In a further embodiment of the process, which provides an even higher deposition rate, a source of N.sup.+ is added which provides charge neutralization and surface nitridation prior to deposition.
    Type: Grant
    Filed: August 14, 1995
    Date of Patent: July 22, 1997
    Assignee: Structured Materials Industries Inc.
    Inventor: Gary Steven Tompa
  • Patent number: 5637258
    Abstract: A process for the production of metal oxide nanocrystalline phosphors activated with a rare earth, line emitting, element. The nanocrystal oxides are produced by a sol-gel like process. The process begins with an n-butoxide solution of the host and activator which is first subject to acetolysis which will cause the pH of the solution to change from basic to acidic. This is followed by the addition of water in a hydrolysis step which forms a host/activator hydroxide solution. To the host/activator hydroxide solution, sodium hydroxide, which is very basic, is added, which will cause the precipitation of host oxide nanocrystals activated with the activator. The host/activator n-butoxide precursors may be synthesized by azeotropic distillation.
    Type: Grant
    Filed: March 18, 1996
    Date of Patent: June 10, 1997
    Assignee: Nanocrystals Technology L.P.
    Inventors: Efim T. Goldburt, Rameshwar N. Bhargava, Bharati S. Kulkarni
  • Patent number: 5592138
    Abstract: The device comprises a winding support (1) which is made of an electrically insulating material and which comprises a coil former (3), provided with a through-opening (9), and a core of a soft magnetic material which consists of two parts (15) and which comprises a limb (19) projecting through the opening of the coil former and a yoke (17) at least partly enclosing the winding support. The two core parts are attached to one another by means of a clamping bracket (21) which is made of a resilient material and which is formed as a closed ring. The construction of the clamping bracket (21) is very inexpensive and it can be very simply mounted on the assembly formed by the core (15) and the winding support (1) in that the clamping bracket consists of one piece of a resilient material which is shaped as a strip comprising barb-shaped free ends (23), which strip is bent so as to form a ring, the facing free ends engaging one another so that the ring is closed.
    Type: Grant
    Filed: January 26, 1994
    Date of Patent: January 7, 1997
    Assignee: U.S. Philips Corporation
    Inventor: Johannes H. Tobben
  • Patent number: 5470805
    Abstract: A novel type of lead-free glass for use in glass components of electric lamps, such as stems (1) for incandescent lamps and fluorescent lamps and lamp envelopes for compact fluorescent lamps. The glass does not contain PbO, F and B.sub.2 O.sub.3. The glass has favorable physical properties as regards meltability, softening, expansion, electric resistance, transparency, strength and chemical resistance.
    Type: Grant
    Filed: November 17, 1994
    Date of Patent: November 28, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Bartholomeus Filmer
  • Patent number: 5442676
    Abstract: Measurements are made on a sample (1) to obtain an experimental profile (2) having structural features (3, 4) determined at least in part by the given characteristic and an expected profile (5) calculated for the sample using selected parameters. A degree of smoothing is applied to the experimental profile (2) to reduce the structural features (3,4) thereby producing a smoothed experimental profile (21 a) and the same degree of smoothing is applied to the calculated profile (5) to produce a smoothed calculated profile 51 a. The smoothed calculated profile (51 a) is compared with the smoothed experimental profile (21 a) to determine the difference between the smoothed profiles. The calculated profile is then modified by varying at least one of the parameters until the smoothed modified profile fits the smoothed experimental profile.
    Type: Grant
    Filed: December 16, 1993
    Date of Patent: August 15, 1995
    Assignee: U.S. Philips Corporation
    Inventor: Paul F. Fewster
  • Patent number: 5387837
    Abstract: A low pressure discharge lamp having a tubular discharge vessel (1). At each of its end portions (2, 3) the vessel (1) is fused to a respective metal tube (5) having an uncovered outer surface outside the vessel. A sealed glass tube (6) is fused to the metal tubes (5). Ignition aids (18, 28, 40) may also be present. The simple construction of the lamp permits manufacture and high lamp quality, even at long lengths and/or small diameters of the discharge vessel. The lamp may have an ionizable filling of rare gas or may also contain mercury. A fluorescent powder may also be present in the discharge vessel. The lamp (72) and a luminaire (70, 71) mounting the lamp may be used for display or signalling purposes.
    Type: Grant
    Filed: March 2, 1993
    Date of Patent: February 7, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Bauke J. Roelevink, Paulus Q. J. Nederpel, Franciscus A. S. Ligthart