Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Abstract: The present invention provides gas discharge laser systems capable of reliable long-term operation in a production line capacity at repetition rates in the range of 6,000 to 10,0000 pulses power second. Preferred embodiments are configured as KrF, ArF and F2 lasers used for light sources for integrated circuit lithography. Improvements include a modified high voltage power supply capable for charging an initial capacitor of a magnetic compression pulse power system to precise target voltages 6,000 to 10,0000 times per second and a feedback control for monitoring pulse energy and determining the target voltages on a pulse-by-pulse basis. Several techniques are disclosed for removing discharge created debris from the discharge region between the laser electrodes during the intervals between discharges. In one embodiment the width of the discharge region is reduced from about 3 mm to about 1 mm so that a gas circulation system designed for 4,000 Hz operation could be utilized for 10,000 Hz operation.

Abstract: A gas discharge laser having a laser chamber with two elongated erodable electrode elements, each having an erodable section and an electrode with support configured to minimize discharge region laser gas turbulence and with the electrode elements being configured to permit gradual erosion over more than 8 billion pulses without causing substantial changes in the shape of electrical discharges between the electrode elements. A pulse power system provides electrical pulses of at least 2J at rates of at least 2 KHz. A blower circulates laser gas between the electrodes at speeds of at least 2 m/s and a heat exchanger is provided to remove heat produced by the blower and the discharges.

Abstract: Apparatus and methods in which one or more taggants that are intrinsically located—or extrinsically placed—in an object, such as a personal identification device like a badge. The taggants are detected by x-ray fluorescence analysis to identify or verify the object or its point of manufacture. The taggants are manufactured as part of the article or the taggant is placed into a coating, label, or otherwise embedded within the object for the purpose of later verifying the presence or absence of these elements by x-ray fluorescence, thus determining the unique elemental composition of the taggant within the object.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: The present invention provides an excimer laser capable of producing a high quality pulsed laser beam at pulse rates of about 4,000 Hz at pulse energies of about 5 mJ or greater. A preferred embodiment is an ArF excimer laser specifically designed as a light source for integrated circuit lithography. An improved wavemeter with special software monitors output beam parameters and controls a very fast PZT driven tuning mirror and the pulse power charging voltage to maintain wavelength and pulse energy within desired limits. In a preferred embodiment two fan motors drive a single tangential fan which provides sufficient gas flow to clear discharge debris from the discharge region during the approximately 0.25 milliseconds between pulses.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: An accordion-fold laptop computer, comprising, a first housing having a first edge and an opposing second edge, comprising at least one each of a processor, a hard disk drive and a display screen; a second housing, attached to the first housing proximate the first edge, comprising a keyboard; a third housing, pivotally attached to the first housing proximate the opposing second edge.

Abstract: An improved power source system, which utilizes power from an external source and is adapted for use with a portable electronic device, comprising, a carrying case, for the portable electronic device, having one or more structural components; a battery charge controller integrated into one or more of the structural components; an AC power supply module integrated into one or more of the structural components, connected to the battery charge controller and adapted to receive power from said power source; one or more rechargeable batteries integrated into one or more of the structural components and connected to the battery charge controller; and a DC Output regulator integrated into one or more of the structural components and connected to the battery charge controller.

Abstract: A tangential fan and cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential position of blade members can shift monotonically or reversibly between ends. Blade members are stiffened by optimally selecting the number and placement of hub members to control the natural vibration frequency of the fan. Methods of forming tangential fans include casting, and machining from a solid block. Monolithic structures can be joined, typically by electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Tangential fans produced have mechanical rigidity, accurate tolerances, and low contaminant concentrations. Blade members can be formed into air foil shapes.

Abstract: A method and apparatus is disclosed for heating metal billets or other separate pieces of metal in a continuous furnace using two different burner systems. The primary burner system provides the majority of available heat at relatively high flame temperatures. The secondary high velocity burner system extrains how furnace products of combustion that impinge around on the load. Thus, heat transfer and temperature uniformity is improved by forcing hot gases between the metal pieces.

Abstract: The described DC to AC inverter efficiently controls the amount of electrical power used to drive a cold cathode fluorescent lamp (CCFL). The output is a fairly pure sine wave which is proportional to an input control voltage. The output waveform purity is ensured by driving a symmetrical rectangular waveform into a second-order, low pass filter at the resonant frequency of the filter for all conditions of line voltage and delivered power. Operating stress on the step-up transformer is minimized by placing the load (lamp) directly across the secondary side of the transformer. When configured to regulate delivered power, the secondary side may be fully floated which practically eliminates a thermometer effect on the operation of the lamp. All of the active elements, including the power switches, may be integrated into a monolithic silicon circuit.

Abstract: A tangential fan and cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential position of blade members can shift monotonically or reversibly between ends. Blade members are stiffened by optimally selecting the number and placement of hub members to control the natural vibration frequency of the fan. Methods of forming tangential fans include casting, and machining from a solid block. Monolithic structures can be joined, typically by electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Tangential fans produced have mechanical rigidity, accurate tolerances, and low contaminant concentrations. Blade members can be formed into air foil shapes.

Abstract: A gas discharge laser with fast response gas temperature control to maintain laser gas temperature within desired limits during burst mode operation. Preferred embodiments include a passive temperature stabilizer having fins with surface areas exposed to flowing laser gas at least equal to the surface area of the cooling fins of a laser gas heat exchanger. Preferred embodiments utilize heating elements and coolant flow control to regulate laser gas temperatures using processors programmed to anticipate idle periods.

Abstract: A tangential fan with cutoff assembly for recirculating a lasing gas mixture has blade members, which vary in circumferential position stepwise from end to end, and/or a tapered anode assembly. The number of blade members can be constant or variable between ends. The circumferential positions of blade members can shift monotonically or reversibly between ends. Blade members can be formed into air foil shapes and are stiffened by one or more transverse annular hub members. Processes for making tangential fans include soldering, casting, and machining from a solid block. Monolithic structures can be joined, typically by soldering or electron-beam welding. Casting, welding, and machining processes introduce no additional contaminants. Soldering produces substantially silicon-free assemblies. Tangential fans produced in accordance with the invention have improved mechanical rigidity, accurate tolerances, and low contaminant concentrations.

Abstract: A flat flame burner is disclosed having flow passages for admitting fuel and air to a burner tile. A structure for producing a rotational flow cooperates with a divergent burner tile in order to produce a radially-divergent flame with a very small axial component and a high degree of entrainment of inert combustion products in a furnace. A portion of the fuel is injected into the entrained furnace products, in order to suppress the rate of combustion, so as to produce an ultra low NOx flat flame burner. The present invention also permits greater versatility and improved operability over previous flat flame burners.

Abstract: A method and system is provided for controlling a selected zone in a fuel fired furnace of the type used for heating work as it moves through the zone from an entrant end to an exit end. The method and system includes providing a fuel fired burner at the exit end for propelling a flame toward the entrant end of the zone, controlling the firing rate or capacity of this flame in accordance with the temperature of the work adjacent the exit end of the zone, continuously establishing a gas temperature for the entrant end of the zone corresponding to the firing rate of the flame and then continuously controlling the length of the flame to obtain the established gas temperature at the entrant end of the zone. The combined adjustment of capacity and flame length in accordance with the measured temperature at the entrant end of the zone controls the heating profile through the zone and increases the efficiency of the heating zone.

Abstract: The improvement in a walking beam oil country tube reheat furnace comprises a first row of burners positioned in spaced relationship and transverse the furnace hearth with each of the burners containing a refractory housing positioned in the limited space between the walking beam pass line and the hearth of the furnace. The burner includes a burner body and a centrally disposed fuel tube so as to define an annular air chamber thereabout. The burner includes a 90.degree. bend so as to fire in parallel relationship to the pass line. The method of retrofitting a top fired walking beam furnace includes inserting at least one unitized bung of said spaced burners through the furnace floor and into the space between the pass line and floor and firing the burners in parallel relationship with the pass line.