Patents Represented by Attorney Gerald M. Fisher
  • Patent number: 4949011
    Abstract: In a multicavity klystron amplifier, the drift-tube bore is larger (46) in proportion to the beam size (10) in the non-interacting space between gaps (28) than its size (22) at the gaps (28). This decreases the spacecharge wavelength so that the overall physical length of the klystron is shortened.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: August 14, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Joseph K. Mann
  • Patent number: 4945464
    Abstract: A DC power supply for a traveling wave tube having cathode, collector and helix electrodes responds to a DC power source and a high frequency switching source. A switch controlled by the switching source is opened and closed at a fixed frequency and variable duty cycle determined by the helix-cathode voltage. A flyback choke is connected to the switch and DC power supply so current flows between the power source via the choke to the switch and a series resonant circuit while the switch is closed. First and second capacitors in separate branch circuits of the resonant circuit are respectively connected to first and second AC to DC converter and voltage multiplier stacks; each multiplier in the stacks includes a pair of branches with oppositely poled plural signal switching diodes and a capacitor. The cathode and helix are respectively connected to output terminals of the first and second stacks, while the collector is connected to a terminal between the first and second stacks.
    Type: Grant
    Filed: September 30, 1988
    Date of Patent: July 31, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Bradley R. Gunn
  • Patent number: 4939485
    Abstract: A monolithic microwave integrated circuit switch includes a series field effect transistor having a source drain path in series with an inductive transmission line including plural taps. Source drain paths of plural shunt field effect transistors are connected to the taps. The source drain paths of the series and shunt transistors are biased so that the series and shunt source drain paths have complementary low and high impedance states. The high impedance state is capacitive, having a value on the order of magnitude of the inductive transmission line. During a first time interval, the capacitive and inductive impedances form a matched low pass filter to supply current from a microwave source to a load. During a second time interval, current from the microwave source flows through the shunt field effect transistors to be decoupled from the load.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: July 3, 1990
    Assignee: Varian Associates, Inc.
    Inventor: John A. Eisenberg
  • Patent number: 4938992
    Abstract: Thermal transfer between a semiconductor wafer and a platen during vacuum processing is provided through a soft, thermally-conductive polymer layer having a thin, hard surface film. The soft polymer layer, which is preferably silicone rubber containing thermally-conductive particles, conforms to surface irregularities on the wafer and has low thermal resistance. The surface film is preferably silicon dioxide in the form of a multiplicity of flat plates integrally formed on the silicone rubber. Adherence of the wafer and of foreign matter to the polymer layer is prevented by the surface film. In addition, the underlying polymer layer is protected by the surface film. A high purity polymer layer is fabricated by evacuating the mold cavity and the resin container prior to injection of resin. The mold for the polymer layer utilizes a hard, smooth mold release surface and a resilient gasket between the platen and the mold release surface.
    Type: Grant
    Filed: October 25, 1989
    Date of Patent: July 3, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Eric L. Mears
  • Patent number: 4931776
    Abstract: A flow sensor for regulating the air flow rate to a cooling system can be formed as a housing for channeling the flow through a retangular cavity and a one piece vane of bent metal strip which deflects and closes an electrical contact at a predetermined air flow rate and opens when the air flow rate falls below a preset threshold level.
    Type: Grant
    Filed: May 19, 1988
    Date of Patent: June 5, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Leo V. Klos, Richard J. Hertel
  • Patent number: 4929867
    Abstract: Shown is an integral two-stage vacuum tube with means for efficient optical coupling of the light from an output screen of the first stage into the photocathode of the second stage.
    Type: Grant
    Filed: June 3, 1988
    Date of Patent: May 29, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Kenneth A. Costello, Hugh F. MacMillan
  • Patent number: 4927438
    Abstract: A load chamber of a load lock is provided with a vertical air curtain which isolates the load chamber from the general clean room environment. Horizontal air flows generated in the load chamber bathe wafers held horizontally in the chamber with filtered air. These horizontal air flows are captured by the air curtain and recirculated to filters which provide horizontal and vertical air flows in the load chamber. If desired, the vertical and horizontal flows may be driven by the air supply mechanism of the clean room itself.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: May 22, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Eric L. Mears, Robert E. Jennings
  • Patent number: 4917556
    Abstract: A modular wafer processing machine is provided which is based on interconnected handling units having wafer handling arms. Each unit can pass a wafer to another unit in the same vacuum environment to a processing module.
    Type: Grant
    Filed: May 26, 1989
    Date of Patent: April 17, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Lawrence R. Stark, Frederick Turner
  • Patent number: 4918714
    Abstract: An X-ray tube exposure monitor for recording the emissions from a diagnostic X-ray tube. A photo diode is mounted inside the X-ray tube bulkhead and detects radiation from the X-ray tube. The photo diode is connected to a high gain amplifier and, in response to radiation being detected, the output of the amplifier sends an electronic signal to a microprocessor. The microprocessor records the emission duration and the temperature of oil around the X-ray tube and increments an exposure count. The recording and exposure count is stored in non-volatile memory which is read later by a service technician.
    Type: Grant
    Filed: August 19, 1988
    Date of Patent: April 17, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Joseph R. Adamski, Richard L. Barrett, Ted Bakowski
  • Patent number: 4916418
    Abstract: A multiply tuned bird cage results from the combination of low pass and high pass filter elements to yield a band reject network behaving as a low pass network at a low frequency and a high pass network at a high frequency. A band pass bird cage coil is obtained by adding a parallel LC combination to each leg of a bird cage coil to create additional poles in the impedance curve z(f).
    Type: Grant
    Filed: March 31, 1989
    Date of Patent: April 10, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Alan R. Rath
  • Patent number: 4916398
    Abstract: The invention demonstrates remote tuning of an NMR probe over a length of transmission line while retaining very high efficiency relative to the equivalent locally turned coil. Fixed capacitances for partial tuning are employed at the load such that a desired range of efficiency is achievable for a selected range of capacitance values at both load and source for the intervening transmission line.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: April 10, 1990
    Assignee: Spectroscopy Imaging Systems Corp.
    Inventor: Alan R. Rath
  • Patent number: 4909314
    Abstract: In a vacuum chamber wafer treating apparatus, a wafer is heated or cooled by introducing a gas at a pressure of approximately 100 to 1000 microns in a region between the wafer and a heating element or heat sink. The gas conducts thermal energy between the wafer and heating element or heat sink.
    Type: Grant
    Filed: April 16, 1987
    Date of Patent: March 20, 1990
    Assignee: Varian Associates, Inc.
    Inventor: Lawrence T. Lamont, Jr.
  • Patent number: 4906953
    Abstract: A broadband interconnection between a microstrip and a coplanar waveguide is provided without use of via holes by using anisotropic etching to form a sloped surface between connection points. The sloped surface is then metallized to provide the interconnection.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: March 6, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Chia-Geng Li, Steve G. Bandy, Majid Riaziat
  • Patent number: 4899059
    Abstract: A mechanical scanning system for a batch ion implanter includes a disk for mounting wafers at sites near its periphery and a disk drive assembly for rotating the disk. The disk and the disk drive assembly are supported in an end station vacuum chamber by a scan arm which extends through a sealed opening in an access door. A scan drive assembly attached to the access door scans the scan arm and the disk in an arc-shaped path. Simultaneous rotation and scanning of the disk cause the ion beam to be distributed over the surfaces of the wafers mounted on the disk. A pivot drive assembly rotates the scan arm and the disk about a pivot axis between an implant position and a load/unload position. The implant angle can be changed without opening or venting the vacuum chamber by loosening the attachment of the scan drive assembly to the access door and rotating the scan drive assembly, the scan arm and the disk about the pivot axis. The access door can be moved on rails to an open position for access to the disk.
    Type: Grant
    Filed: June 9, 1989
    Date of Patent: February 6, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Avrum Freytsis, Richard J. Hertel, Eric L. Mears
  • Patent number: 4895809
    Abstract: A method and apparatus for quantitatively analyzing, in a flowing stream, materials in a biological or chemical sample utilizes immobilized antobodies reversibly precharged with fluorescently labeled antigens. The labeled antigens are competitively displaced by unlabeled antigens in the sample, after the sample antigens have been segregated into zones by a chromatographic device, such as the reverse phase high performance liquid chromatograph. Displaced labeled antigens are measured by a fluorescence detector. A plurality of antibody species may be concurrently utilized, thereby allowing quantification of a plurality of antigens from a single sample.
    Type: Grant
    Filed: January 9, 1984
    Date of Patent: January 23, 1990
    Assignee: Varian Associates, Inc.
    Inventors: Timothy D. Schlabach, Fred E. Regnier
  • Patent number: 4888553
    Abstract: Synchronous apparatus capable of a variety of operational states responds to a sequence of digital control words, each specifying a desired state and persistence time of the state. The control words are furnished to the apparatus from a self-clocked FIFO in accord with the persistence code. A selected sub-sequence of digital control words in ROM is placed in an auxiliary FIFO upon detection of a corresponding token in the main sequence and control is passed to the auxiliary FIFO to furnish the sub-sequence to the apparatus. At the conclusion of the sub-sequence control is returned to the main FIFO and the main sequence is resumed.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: December 19, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Robert S. Codrington
  • Patent number: 4881979
    Abstract: In order to increase the efficiency of solar cells, a monolithic stacked device is constructed comprising a plurality of solar sub-cells adjusted for different bands of radiation. The interconnection between these sub-cells has been a significant technical problem. The invention provides an interconnection which is an extremely thin layer of gold formed between the sub-cells by organometallic chemical vapor deposition. Such a layer tends to form beads which serve as a low resistance shorting interconnect while passing a large fraction of the radiation to the lower sub-cells.
    Type: Grant
    Filed: March 22, 1988
    Date of Patent: November 21, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Carol L. R. Lewis
  • Patent number: 4878235
    Abstract: Several different embodiments of high-intensity rotating-anode X-ray are shown which use a liquid or fluid-cooled rotating-anode. No ferrofluid-type rotating joints or O-ring gasket-type seals are required so that the interior of the tube maintains a high vacuum without pumping. A bellows permits mechanical coupling to interior structures of the tube while providing a completely vacuum tight enclosure. All joints may be hard soldered or brazed together so the entire system can be baked at a high temperature during pumpdown.
    Type: Grant
    Filed: February 25, 1988
    Date of Patent: October 31, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Weston A. Anderson
  • Patent number: 4876687
    Abstract: A free-electron laser has a wiggler for a linear electron beam comprising two sets of magnetic polepieces 26, 28 periodically spaced along opposite sides of the beam. The polepieces of one set 28 are displaced along the beam from the other set 26 by one-half period. A uniform longitudinal magnetomotive force generates fields between polepieces having transverse components 22 alternating between the sets 26, 28, providing a very short periodicity and hence, high frequency wave radiation.
    Type: Grant
    Filed: February 13, 1989
    Date of Patent: October 24, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Joseph Feinstein
  • Patent number: 4875487
    Abstract: A wide bandwidth compressional wave transducer array obtains information concerning tissue of a subject being treated and supplies hyperthermia compressional wave treating energy to a treated region of the subject. The array transducers are pulsed on and off with an on duty cycle portion of less than one. An array of compressional wave imaging transducers is in the center of the array of compressional wave hyperthermia focused far field transducers used to analyze and treat. The power and duty cycle of the compressional wave hyperthermia focused far field are varied to control the energy incident on certain regions in a treated subject. The ultrasonic frequencies of hyperthermia beams derived from individual transducers are randomly angle modulated so the energy of adjacent far field focused beams overlaps to a greater extent than focused coherent beams.
    Type: Grant
    Filed: May 2, 1986
    Date of Patent: October 24, 1989
    Assignee: Varian Associates, Inc.
    Inventor: Edward J. Seppi