Abstract: A photomultiplier tube includes a photocathode and a primary dynode having input and output apertures. A field isolating mesh is positioned at the input aperture of the primary dynode to facilitate the collection of electrons from the photocathode of the photomultiplier to the primary dynode while simultaneously electrostatically shielding secondary emission electrons from the field of the photocathode. The field isolating mesh has a central opening that is dimensioned to maximize the throughput of photoelectrons from the photocathode to the primary dynode while providing effective field isolation in the vicinity of the primary dynode. The central opening in the field isolation mesh provides the further advantage of permitting uniform deposition of photo-emissive materials on the surface of the dynode during manufacture. In an alternative embodiment, the field isolating mesh of the primary dynode is formed in two segments.

Abstract: An electron multiplier with a source for spontaneously generating electrons is used as an electron source for an ionization source in a mass spectrometer or the like. The electron multiplier can be a microchannel plate, in which case it produces a wide electron beam. The microchannel plate can be acid-leached to provide a surface for spontaneous generation of electrons, or the first strike surface can be coated with an alkali-containing material. The electron source can be tuned by providing an electrode for rejecting electrons having too high an energy and a grid for rejecting electrons having too low an energy.

Abstract: The structure is an improvement to prevent thermal cycle damage to a braze joint in a magnetron filament assembly. The filament is welded to a molybdenum filament weld ring which, in turn, is brazed to a solid iron filament support cylinder. This braze joint is sometimes broken because of the different thermal expansion coefficients of molybdenum and iron, even though slots are formed in the molybdenum cylinder to reduce the stress. The improvement is the addition of a thin yieldable cylinder along the top outer edge of the iron support cylinder to which the molybdenum cylinder is brazed. This thin cylinder can be constructed by cutting an annular groove adjacent to the top outer edge of the iron support cylinder. The groove then forms the cylinder to which the weld ring is attached, and the thin iron cylinder yields with thermal stress and therefore relieves the stress on the adjacent braze joint.

Abstract: A unitary removable shield, serving the same function as a film or coating of electrically conductive material applied over the conductive cavity of a universally adaptable corona generating or charging device, is inserted into the cavity to adsorb and desorb nitrogen oxide species produced by negative corona. The unitary removable shield has a generally U-shaped cross-sectional configuration which fits within the cavity. The shield may be retained in the housing by engaging and conforming to the shape of the conductive cavity in a tight frictional fit so as to make electrical contact with the conductive cavity. The shield may also be retained in the housing by tabs or pressure-loadable clips which engage portions of the housing.

Abstract: A photomultiplier tube is disclosed having a first dynode array and a second dynode array oriented substantially orthogonal to the first dynode to provide a shortened profile. The first dynode array is preferably a box-and-grid dynode array and the second dynode array is preferably an in-line dynode array. A focusing electrode is positioned between the last dynode of the first dynode array and the first dynode of the second dynode array. The focusing electrode is constructed and arranged to facilitate the transfer of electrons emitted from the first dynode array to the second dynode array without generating secondary electrons.

Abstract: A system for detecting motion in a video image is provided wherein the video image is processed into a statistical array in which the array elements are derived from overlapping portions of the image. The elements of the statistical array are compared with corresponding array elements derived from an earlier image. The overlapping nature of the statistical array elements allows any detected changes in the image to be correlated with a portion of the image that is smaller than the area from which the statistical quantities are derived. Such spatial correlation of detected image changes is accomplished by thresholding and/or Boolean comparisons among the elements of the statistical array. A motion detection system in accordance with this invention can be used with a video multiplexing system so that motion can be detected at a plurality of remote locations.

Abstract: The invention is a turnstile gate with a serpentine configuration instead of conventional protruding arms. Both the stationary and revolving gates are formed of a continuous configuration of pipe which loops back and forth with substantial straight sections oriented horizontally. In order for the movable gate to pass through the stationary gate, the loops of the stationary gate must be offset from those of the revolving gate by one-half a cycle, and the loops of at least one of the gates must vary in their heights so that they can be located both outside and inside of the loops of the opposing gate. The advantages of the configuration are safety, ease of manufacture and greater strength, with a unique aesthetic appearance.

Abstract: A multiple section photomultiplier tube. The tube is constructed essentially as a matrix of several independent tubes in one envelope. The photocathode of each individual section of the tube is formed into an independent surface, and the photocathode to dynode spacings are isolated by a configuration built with separator electrodes which connect to photocathode boundary dividers formed in the faceplate. The boundary dividers also isolate the independent photocathode regions. The boundary dividers can be either slots into which the separator electrodes fit or ribs with which the separator electrodes are engaged.

Abstract: A motor driven panoramic mounting for cameras which provides an automatic pan range and the ability to pan over 360 degrees. Mechanical actuators on a fixed base act upon a turnstile on a shaft on the rotating table, with the turnstile shaft also rotating two cams that actuate three limit switches. One cam acts upon a single limit switch which determines the automatic range and reverses the table motion at the ends of the automatic range. The other cam acts on two end limit switches which stop the motion. The action of the turnstile and switches brings the table back to the preset automatic range regardless of where it is directed when it placed back in the automatic mode.

Abstract: A control panel structure for electronic equipment. The structure comprises multiple layers in which an electronic chassis has attached to it, in sequence, a bezel, a PC board which fits into a cutout on the bezel, a cover inset to align and lock the other parts together, and an adhesive backed overlay to furnish labels and decorative features. The assembly is held together by split bosses extending back from the bezel. The bosses fit into holes in the chassis, with the bosses expanded so that they fit tightly into the holes by alignment pegs which extend back from the cover inset and fit tightly into the bosses.

Abstract: A photomultiplier tube in which the a semiconductor photodiode serves as the anode and receives the electrons from the photocathode. The particular geometry for the focusing electrodes in the tube involves a two part structure with one part, the anode focus electrode, in close proximity to the semiconductor photodiode. The second part of the focus structure is a grid focus electrode with two different diameters, located approximately midway between the photodiode and the photocathode and operating on a low voltage. Together the electrodes create a focusing electric field so that the electrons from the large area photocathode are efficiently delivered to the small area of the semiconductor photodiode. The mounting of the photodiode is also designed to act as a termination to furnish superior timing characteristics.

Abstract: A sealed and pressurized housing for a TV camera. The camera is mounted on a cradle which includes the sealing mechanism for both ends of the housing. Both ends are sealed with conventional "O" ring seals and end plates which are secured to the cradle. Since pressure is always equalized against both end plates and they are mechanically connected, when the housing is opened, no parts can be dangerously propelled upon release of the pressure. The cradle is also mounted so that, despite the internal pressure, it can be rotated relative to the fixed outer casing in order to adjust the angle of the camera to the horizontal.

Abstract: A multiple section photomultiplier tube constructed as a matrix of several independent tubes in one envelope. The photocathode to dynode spacings are isolated by a separator configuration built with walls which interlock in cooperating slots, and each photocathode operates with its own independent dynode cage. One dynode in each cage is maintained electrically independent, and its connection is brought out of the envelope independently. This permits independent adjustment of the gain for each of the tube's multiple sections, so they can be adjusted to the same response for a standard radiation signal. The entire tube can then be used to monitor a large area for radiation, and will yield the same response over its entire cathode area.

Abstract: A focus electrode for an elongated hexagonal faceplate photomultiplier tube. The elongated hexagonal face plate and an off-center cage assembly are made to function properly in a photomultiplier tube by the use of a uniquely shaped asymmetric focus electrode. The focus electrode has a base which is a partial circle with two parallel chords and is constructed with a side wall around the perimeter of the base. The side wall has different heights above the two parallel chords of the base and slopes down to minimum but equal heights at points on the curved perimeter which are approximately at the center plane of the tube.

Abstract: A low torque apparatus for tilting platforms. A leg attached to the platform protrudes from the bottom of the platform to a motor shaft which penetrates one of two vertical sides which form a box-like support structure for the platform. The platform pivots on supports which slide in horizontal slots near the top of each vertical side. The motor is mounted so that it slides in near vertical slots in the vertical sides of the support box to maintain the fixed distance between the motor shaft and the tilting platform.

Abstract: A lubrication retainer and distribution system for a worm gear and the mating worm. Porous pads saturated with lubricating fluid are attached to both sides of the worm gear and located so that they spread slightly and wipe the high ridges of the worm. To equalize the fluid distribution between the pads, at least one through hole is formed in the worm gear between the pads, and the hole's size is selected so that capillary action transfers the fluid between the pads as required. Also, to retain the lubricating fluid on the worm, "O" rings are fitted tightly upon the worm shaft just beyond the spiral thread of the worm to act as barriers to prevent fluid from escaping from the system along the worm shaft.

Abstract: A digital motion verification circuit for a television system. The circuit synchronizes an actual and a stored signal from an edge motion indicator with the system clock, so that the edge signals are precisely timed and do not have errors from overlapping or mistimed signals. The circuit uses an EXCLUSIVE OR circuit followed by an inverter stage to produce an output when the clock synchronized stored signal and the actual signal have a discrepancy. This EXCLUSIVE OR output signal is applied to the data input of a shift register that produces clock synchronized output signals which, when accumulated to a predetermined number, initiate a motion flag which indicates the presence of several exactly adjacent signals.

Abstract: A power supply which automatically adapts to different input power sources. A double pole, double throw, latching relay switches the primaries of the rectifier transformer to a series or to a parallel configuration depending upon the output voltage of the rectifier, thus adapting the circuit to either a nominal 220 VAC source or a nominal 120 VAC source. The control circuit also derives power from the rectifier transformer and is designed to operate even under the worst possible undervoltage or overvoltage conditions. The additional choice of 24 VDC power is available by the use of a diode OR circuit. When a 24 VDC source is connected to the DC input, it is also connected to the rectifier output through a diode, so that power is furnished to the load by whichever source has the higher voltage. In this configuration, a battery pack can be connected to the DC input to supply automatic backup power.

Abstract: A vertical phase adjust circuit with high noise immunity for line locked surveillance cameras. To prevent noise from the AC line producing false output signals, a counter is used to lock out the delayed vertical line locked output signal. The horizontal scan frequency is counted from the time a vertical output is produced, and the vertical output signal is prevented until 98 percent of the period between legitimate vertical signals has elapsed. The circuit also includes a lock detect circuit to increase the time window during startup conditions to assure initial synchronization and an increased phase adjust range to permit synchronization with any other camera.