Abstract: A semiconductor defect monitoring structure employs a series of electrically testable serpentine stripe patterns having different widths and spacing in order to determine the distribution of the density of defects by size. Metal stripe patterns are superposed and rotated 90.degree. with respect to diffusion stripe patterns in a semiconductor wafer. A set of four field effect transistor devices are connected to each stripe pattern in such a way that tests may be made for all defects without interference between adjacent patterns. The defect monitoring structure helps to determine defects such as opens in diffusion and metallization, shorts in metallization, shorts in diffusion, pinholes in a thin oxide, and pinholes in a thick oxide.

Abstract: A phase difference detector and display unit. A digital pulse train at the frequency to be measured is combined with a multiple-phase digital clock output having a reference frequency to produce multiple-phase signals which low-pass filters convert to dc output signals. Each output signal indicates the instantaneous phase difference between the digital pulse train and a respective one of the clocking signals.Each dc output signal controls the light from a pair of lamps. Individual lamps in each pair are diametrically opposed on a circle with all the pairs being spaced around the circumference of the circle. The lamp pairs reach maximum brightness in sequence, providing the illusion of a rotating light bar. The direction of rotation indicates whether the digital pulse train is higher or lower in frequency than the reference while the speed of rotation is proportional to the frequency deviation from the reference.

Abstract: The nonlinear properties of the ternary ferroelectric barium fluorides permit noncritical phase matching in the vicinity of 1.06 microns at room temperature. The crystals can tolerate powers of up to approximatey 10.sup.9 watts/cm.sup.2 and may be used as the essential element in second harmonic generators. These devices operate at room temperature without any need for sophisticated temperature control.

Abstract: Described is a technique for obtaining phase matched second harmonic generation in a laminar structure with the optical radiation propagating parallel to the layers.

Abstract: A network for clamping a circuit node to a voltage level when the circuit is subjected to high radiation levels. The network includes a first resistor connected in series with a first radiation responsive element between said circuit node and a first point of potential and a second resistor connected in series with a second radiation responsive element between said circuit node and a second point of potential. In response to high radiation levels, the equivalent impedance of the radiation responsive elements decreases considerably and the potential at the circuit node is clamped to a voltage which is primarily determined by the potentials applied at said first and second points and the ratio of the first and second resistors.

Abstract: The conductivity cell is utilized in a particle study device of the type wherein liquid electrolyte containing particles is caused to traverse an electrical sensing zone of small dimensions, sensing electrodes being located on either side of the sensing zone. The conductivity cell includes two electrodes situated in the electrolyte and being coupled to an electrical sensing circuit including the sensing electrodes. The resistance across the sensing electrodes and the resistance across the conductivity cell electrodes are connected in series with the power source and function as a voltage divider. The junction between the two resistances is coupled to a signal detecting amplifier so that a change in the conductivity of electrolyte will cause a change in both of the resistances whereby the voltage at the junction between the two resistances is essentially constant.

Abstract: Apparatus for obtaining automatically the distribution of volume or mass of particles suspended in a sample. The sample is analyzed in successive sequences or sections each representing a magnitude of given particles. A counter is provided for counting the particles in the sections, and a measuring circuit determines a value which is proportional to the time required by the counter to obtain the number of counted particles. The values are transmitted by a differential circuit to a display device which records directly, such as in a graph, the distribution of the particles in the sample.

Abstract: Apparatus for selecting the focal length of a camera lens which focal length will provide a desired field size, image size and angle of view. The apparatus has a housing and three lens axially aligned therein: A first lens of the converging meniscus type, a second lens of the plano-convex type, and a third lens system of the biconcave type mounted for axial movement between the first and second lenses. The biconcave lens element is formed of plastic and has a handle means preferably integral therewith which extends through a longitudinal slot in the housing to facilitate such movement. Indicia means adjacent the slot on the housing indicates focal lengths. The third lens system is configured to move within opposed, parallel inside walls of the housing smoothly.

Abstract: The method of the present invention consists in passing a pulsating current through two series-connected working phase windings of the stator of an electric motor and determining the relationship between the displacement angle and phase voltages and line voltages across said windings.This relationship is then used for determining the displacement angle of the electric motor which in this case is a synchronous reluctance motor operating in braking duty under conditions where there is no access to the motor shaft. Normally, this is the case with motors employed as an actuating means in the control and protection systems of nuclear reactors.The device for carrying out the above method comprises a voltage comparison unit and an indicating instrument.

Abstract: An illuminating device for a microscope provided with a lighting control circuit controlled by changing the firing angle for which an impedance means is inserted between the output side of said lighting control circuit and primary side of the transformer in order to obtain a gentle rising curve for the current at the time of firing, thus to reduce the noise.

Abstract: A vehicle location system is provided for determining the coordinate location of a vehicle through radio transmission radiation from the vehicle and the system includes a plurality of receiver sites at known coordinate locations each having antenna-coupler means providing first and second signals whose phase difference is approximately linearly related to the azimuth angle of the receiver signal from the radiation source. The first and second signals are processed at each receiver site to translate the frequency of the signals to a lower frequency and to remove the common frequency variations therefrom. Thereafter, the signals are passed through a phase detector which provides a binary output expression which is linearly related to the phase difference between the first and second signals.

Abstract: Self-supporting luminescent screens made by applying a releasing agent to the surface of a mechanical supporting structure, having the desired shape, which agent is bound with a binding substance that is volatile at the evaporating temperature of a luminescent screen material, the latter being then deposited in a layer by evaporation onto the prepared supporting surface, until the deposited screen layer reaches a desired thickness, and eventually separating and removing the produced luminescent screen from the supporting structure.

Abstract: A beam limiter circumscribes the interior surface of a vacuum vessel to inhibit collisions of contained plasma and the vessel walls. The cross section of the material making up the limiter has a flatsided or slightly concave portion of increased width towards the plasma and portions of decreased width towards the interior surface of the vessel. This configuration is designed to prevent a major fraction of the material sputtered, vaporized and blistered from the limiter from reaching the plasma. It also allows adequate heat transfer from the wider to the narrower portions. The preferred materials for the beam limiter are solids of sintered, particulate materials of low atomic number with low vapor pressure and low sputtering and blistering yields.

Abstract: In apparatus for measuring the electrical resistance of a liquid employing two parallel channels for the liquid, a single induction coil is located at one of the points of connection of the channels and a single measuring coil at the other of said points of connection. In this way, parasitic electric circuits in the liquid and mutual interaction between the coils are avoided. The coils are preferably arranged coaxially above respective circular passages connecting the parallel channels.

Abstract: Apparatus is disclosed for detecting and measuring peak-to-peak values in an electrical input signal, the signal comprising at least one positive-going and one negative-going peak and can include waveforms characterized by short duration and fast rise time pulses. In operation, one of the at least one input signal peaks is referenced to a predetermined d.c. voltage level, such as, for example, 0 volts d.c., and an electrical output signal is generated which is representative of the magnitude of the input signal with respect to the predetermined d.c. voltage level. The output signal is generated by electrical circuitry capable of accurately tracking fast rise time pulses and then stretching the other unreferenced at least one peaks to prevent decay thereof.

Abstract: The transistors of a differential amplifier are coupled at their common emitter electrode connection to a low voltage power supply terminal and at their collector electrodes through respective current sinks to a point of reference potential. The collector electrodes are maintained at a voltage level above the reference potential to permit input signal swings at the base electrodes of the transistors a comparable amount below the reference voltage level. Current sources are provided for satisfying that portion of the current demand of these sinks not furnished by the transistors. When the amplifier is connected to operate as a voltage follower, additional transistors may be provided to prevent an undesirable change in the polarity of the output signal, when the input signal swings substantially below the reference voltage level.

Abstract: An a-c plasma display panel including apparatus for driving the keep-alive cell sustain signal circuits in a non-fixed relation with address pulses. By constraining the keep-alive cells to be sustained in a time relation dependent on the address of a cell being addressed it is possible to increase the margins for the address signals and, in general, permit a reduction in magnitude of such address signals.

Abstract: A conductivity monitoring system including a temperature sensing means for sensing the temperature of a fluid and also providing a temperature compensated conductivity signal. Electronic circuitry is provided for detecting and indicating the inoperability of the temperature sensor.

Abstract: High-intensity arc-discharge (HID) device of the metal-halide additive type incorporates as essential discharge-sustaining constituents mercury and inert ionizable starting gas and also sodium and/or lithium iodides and/or bromides as well as scandium iodide and/or bromide. The molar ratio of alkali metal halide to scandium halide is from about 1.7:1 to about 5:1 and this greatly enhances the device efficacy for the generation of visible light, which can be enhanced by as much as 32 percent.

Abstract: The invention relates to apparatus for the testing of high circuit density devices fabricated by large scale integration techniques. More specifically, the invention is directed to a test fixture used in a test system for determining the merit or electrical integrity of small semiconductor chips, diced from a semiconductor wafer having a large number of chips. Each chip being a high circuit density device, e.g., a small monolithic semiconductor structure having a large number of closely spaced circuits thereon and therein.