Abstract: Mid and deep ultraviolet light transmitting pellicles for protecting photomasks from particle contamination during a projection printing process. The pellicles are manufactured from polyglycidyl-methacrylate-ethacrylate copolymer, from polyvinyl butyral polymer or from nitrocellulose. The polyvinyl butyral pellicle is sandwiched between two layers of an antireflective coating of poly-1H, 1H Pentadecafluorooctyl methacrylate or poly-1H, 1H Pentadecafluorooctyl acrylate. The nitrocellulose pellicle includes two double layers of antireflective material with the first double layer positioned on one side of the nitrocellulose layer and comprising a layer of the thermoplastic phenolic resin novalac and a layer of either poly-1H, 1H Pentadecafluorooctyl methacrylate or poly-1H, 1H Pentadecafluorooctyl acrylate.

Abstract: Flyback converters can generate multiple voltage levels by rectifying and filtering multiple windings on a single power transformer. Different voltages should be related by the turns ratio of the respective windings. Transformer leakage inductance causes leading edge voltage spikes on some windings causing the filters to peak charge to a higher value than expected. The addition of a small coupled inductor between two or more windings will block the leading edge spike allowing the filter to charge to the correct voltage. The turns ratio of the coupled inductor is selected to cancel the leading edge voltage spike on the desired winding. The coupled inductor can be used to correct the voltage of a winding used for feedback purposes as well as improving the cross regulation between multiple converter outputs.

Abstract: A transistor configured as a capacitor is connected between the gate and drain of an output, pull-down transistor to limit the rate of change (di/dt) of the current conducted through the pull-down transistor during the turn-on of the transistor to limit ground bounce (transients). Drive for the pull-down transistor is provided, in part, by a NOR gate, the transistors of which are sized to provide a finite resistive to the pull-down transistor. Additional drive for the pull-down transistor is provided by a transistor connected to function as a resistive pull-up between the gate and the drain of the pull-down transistor.

Abstract: In a ballast circuit for producing a DC signal with a high voltage amplitude, a capacitor is connected to a circuit output. The capacitor stores a charge which provides the high voltage amplitude of the DC signal. Current from an inductor is used to charge the capacitor. A current gate, when it is turned on, drains current from the inductor. A control circuit turns the current gate on and off so that the amplitude of the current drawn from the incoming AC voltage signal is in phase with the amplitude of the voltage of the incoming AC voltage signal. The control circuit includes a ramp generator which generates a pulse modulation reference signal with a varying voltage amplitude and a comparator which compares the pulse modulation reference signal with the incoming AC voltage signal after the incoming AC voltage signal has been rectified and the voltage divided by a voltage divider. The comparator produces a first modulated signal.

Abstract: An apparatus and method for determining the location of a concealed conductive object. The method includes the steps of determining the lateral position of the object by using an antenna array to detect a signal propagating on the object. The antenna array is comprised of at least one center antenna positioned perpendicular to a surface concealing the object and at least two antennas symmetrically positioned about the center antenna at angles not equal to ninety degrees. The depth of the concealed object is determined by using a bottom sensor to detect the signal propagating on the object as a first signal. A vertically displaced top sensor then detects the signal as a second signal which is amplified by a variable gain amplifier until it equals the first signal. The depth of the object is calculated from the gain increase required to achieve equality between the first and second signals.

Abstract: Disclosed is a (4T-2R) SRAM cell and method which achieves a much reduced cell area through the combined use of vertical trench pull-down n-channel transistors and a buried-layer ground plate. The reduced cell area allows the fabrication of a higher density SRAM for a given set of lithographic rules. The cell structure also allows the implementation of a (6T) SRAM cell with non-self-aligned polysilicon p-channel pull-up transistors without appreciably enlarging the cell area.

Abstract: An apparatus and method for detecting vertically or horizontally oriented underground electrical conductors such as electrical wiring or rails in tunnels thin conducting ore veins surrounded by less conducting rock, or boreholes filled with conductive water or lined with a conductive casing. The apparatus includes a surface or downhole transmitter and a downhole receiver connected to a coherent frequency source unit by fiber optic cables. The source unit generates two phase synchronized frequency signals in the range of one hundred to three hundred kHz. The receiver includes a vertical or horizontal magnetic dipole antenna, e.g. a ferrite rod antenna, and the transmitter includes a vertical or horizontal magnetic dipole antenna in the downhole configuration or at least one long cable or loop antenna in the surface configuration.

Abstract: A chemical vapor deposition (CVD) reactor and method are disclosed wherein a chamber, preferably configured for receiving a single wafer as a deposition substrate, has multiple gas inlet orifices and exhaust ports which are independently adjustable for dynamically varying and controlling directionality of local gas flow vectors toward and past the deposition substrate. The injection angle of reactant gas being introduced into the chamber is adjusted by baffles for statically deflecting gas flow entering the chamber. Adjustment of the gas inlet orifices and/or exhaust ports and adjustment of the injection angle for the reactant gas is selected for achieving enhanced coating uniformity, and conformality of deposition if necessary or desired, on the substrate.

Abstract: Disclosed is a (4T-2R) SRAM cell and method which achieves a much reduced cell area through the combined use of vertical trench pull-down n-channel transistors and a buried-layer ground plate. The reduced cell area allows the fabrication of a higher density SRAM for a given set of lithographic rules. The cell structure also allows the implementation of a (6T) SRAM cell with non-self-aligned poly-silicon p-channel pull-up transistors without appreciably enlarging the cell area.

Abstract: A portable warming container having an electric heating element, a temperature sensor, a battery, a wire loop, and a control circuit. The wire loop is arranged to charge the battery through the control circuit, and the temperature sensor ultimately controls the current delivered to the heating element from the control circuit and battery.

Abstract: A first and second conduit are connected together by a screw thread attachment. A gasket hermetically seals the first and second conduit together. The first conduit has a seal member which is shaped to engage a sealing surface of the first conduit. Spring washers force the seal member against the sealing surface. The seal member has an extension which engages the gasket such that when the conduits are screwed togther, the seal member is lifted off of the sealing surface.

Abstract: Circularly polarized light is used to detect an end point of a thin film layer. Collimated light is passed through a polarizing filter and a polarizing beam splitter resulting in light which is almost entirely linearly polarized in a first direction. This first direction polarized light is passed through a quarter wave retarder and is converted to circularly polarized light. The circularly polarized light is reflected off of a surface having a thin film layer and passes back through the quarter wave retarder. This reflected circularly polarized light is converted by the quarterwave retarder into linearly polarized light having a second direction. This second direction polarized light is easily isolated by passing it back through the beam splitter. The light may then be analyzed by end-point detection circuitry and the end-point of the film layer detected.

Abstract: To reduce error introduced by the local oscillator in the velocity calculations, the receiver has two "tracking channels" and a microcomputer. With numbers required to, simultaneously, lock each of the "tracking channels" each to a respective satellite signal, the microcomputer employs a differential doppler technique to calculate the receiver velocity. The microcomputer calculates a number which represents the difference between the apparent doppler frequency shift of the carrier signal which is transmitted by the first "tracking channel" satellite and which is measured over a specific time period and the apparent doppler frequency shift of the carrier signal which is transmitted by the second "tracking channel" satellite and which is measured over substantially the same time period.

Abstract: A carriage assembly for use with high track density flexible magnetic disk drive systems that comprises a base carriage, which supports a permanent magnet, driven by a stepper motor used to achieve course positioning of the carriage assembly. A fine position acutator is attached to the base carriage by a pair of flexible metal strips that permit movement of the actuator relative to the base carriage for fine positioning of a pair of magnetic heads. The fine position actuator comprises a voice coil bobbin, an upper arm which supports an upper magnetic read/write head, a lower arm which supports a lower magnetic read/write head and a hinge which connects the upper and lower arms. An optical servo tracking assembly mounted on the actuator senses optical servo tracking information on a surface of a magnetic disk and generates a signal which activates the voice coil bobbin causing movement of the actuator relative to the base carriage.

Abstract: A method for remotely monitoring conditions such as carbon monoxide for methane gas concentration, longwall roof support pressure, machine parameters or uncut coal, trona or potash layer thickness in a natural resource mining system such as a longwall or continuous mine system. The method utilizes a plurality of sensors connected to low magnetic moment transmitters, e.g. 0.1 ATM.sup.2, or high magnetic moment transmitters, e.g. 2.5 ATM.sup.2, that transmit collected data during multiple short burst transmission periods. Prior to transmission, the data is converted to a digital word format. An algorithm in the transmitter microcomputer ensures that random time intervals exist between data transmission bursts thus preventing a data transmission clash at the central receiver. A microcomputer algorithm in the central receiver protects against data contention caused by simultaneous transmission from several sensors.

Abstract: A cable pulley transmission has a plurality of pulleys with flight receiving pockets, an endless cable trained about the pulleys, and a plurality of flights located at spaced intervals along the cable. The flights on the cable fit into the flight receiving pockets of the pulleys for transmitting motion between the pulleys and the cable. Each of the flights are formed by two half-sections that are mounted together about the cable. Such a transmission can be used as a lift for liquid. One pulley is located in a source of liquid and at least one pulley is located above the liquid source. The cable has an ascending section and a descending section. The flights are spaced to maintain a column of liquid surrounding the ascending cable section.

Abstract: A magnetic information storage medium, such as a floppy or rigid magnetic disk having a plurality of indelible grooves inscribed on a surface of the medium to function as optical servo tracks. The grooves can be in the form of a plurality of continuous or noncontinuous concentric circles. The grooves can also be a continuous spiral or a plurality of continuous concentric circles having non-constant widths and/or depths.

Abstract: An optical servo head and method for reading position information on a medium, such as a magnetic disk, having a plurality of optical servo tracks in the form of relatively nonreflective regions on a reflective surface of the medium. With a magnetic disk, the nonreflective regions comprise concentric grooves etched in the disk surface and the reflective regions comprise the land areas between the grooves. The optical servo head is mounted on a carriage/head assembly of a disk drive and comprises an infrared light emitting diode, a collection lens, a routing mirror and a multicell photodetector.

Abstract: A lamp reflector includes a light reflecting surface having a transverse cross-section with at least one spiral curve therein beginning behind a light source and curving thereabout with an every increasing radius of curvature. Light striking the spiral curve is reflected around the light source in the direction of the increasing radius of curvature to a location forwardly of the light source. Such a reflector can be adapted for use with light sources of cylindrical, toroidal and spherical shape. The reflector can be adapted for use with a light source enclosed within a transparent or translucent envelope.