Abstract: A transformer in which the primary coil and the secondary coil are insulated from the iron laminations which form part of its flux paths by insulated covers which snap-on to the primary and secondary coils.

Abstract: An electrical connecting device having a receptacle and a two part plug inserted into the receptacle. The two part plug includes an inner part for holding a plurality of zero gap insulation displacement connectors and an outer part for receiving a corresponding plurality of insulated wires. The inner part of the plug can be inserted partially or fully within the outer part of the plug. When the inner plug part is in its partially assembled position, the insulated wires can be easily inserted into the outer part of the plug. When in its fully assembled position, the plurality of connectors within the inner part of the plug are in electrical contact with the insulated wires.

Abstract: A television receiver comprising an improved interface circuit which automatically activates a PIP display of an auxiliary input (for example a videocassette or videodisc) when such an input is detected.

Abstract: A ballast for lighting an auxiliary source of illumination whenever a primary source of illumination fails to ignite. The auxiliary source of illumination is effectively turned OFF by placing a short circuit thereacross whenever the primary source of illumination is lit. The short circuit is removed whenever the primary source of illumination fails to reach a predetermined level of illumination thereby permitting current to flow through and light the auxiliary source of light. The ballast also includes a power factor correction device for increasing the ballast power factor when the primary source of light reaches a predetermined level of illumination.

Abstract: An integrated high voltage differential sensor which uses the inverse gain of a pair of parasitic JFETs to provide a low power circuit for translating a differential high voltage signal down to a lower voltage level that can be easily sensed by the low voltage control circuitry in a power IC and without the use of a resistive voltage divider. The IC includes, between a first high voltage input and ground, a first series circuit of a first JFET, a first voltage level shifting resistor and a bias current source (I.sub.B). A second series circuit of a reference resistor (R.sub.L), a second JFET, a second voltage level shifting resistor and a bias current source (I.sub.B) is coupled between a second high voltage input and ground. A feedback circuit including an operational amplifier is coupled between a low voltage point of the first series circuit and the gates of both JFETs so as to adjust the bias voltages of the JFETs.

Abstract: A programmable transistor includes impurity regions to reduce punch-through and soft-write phenomena. In order to provide a fast operation, the impurity regions are arranged with regard to one another so that parasitic capacitances at junctions of impurity regions of mutually opposite conductivity type are minimized. For these purposes, the transistor comprises a charge storage region over a channel region in a main semiconductor zone of a first conductivity type located between a source and a drain of a second conductivity type opposite to the first. A first impurity zone of the first conductivity type, substantially laterally contiguous with the drain, extends into the channel region and is more heavily doped than the main zone. The drain includes a heavily doped third impurity region and a lightly doped second impurity region that lies at least mainly between the third region and the zones.

Abstract: A high intensity discharge ballast having an ignitor which shuts off after a predetermined time period has elapsed. The ballast is sensitive to voltage dips in power line voltage and resets a timer whenever the power line voltage drops below a level sufficient for lighting a lamp load. Restart of the lamp load immediately following restoration of power line voltage is achieved without requiring that the power line voltage be removed from the ballast or otherwise reduced to approximately 0 volts before restart can be initiated.

Abstract: In a color projection display system employing display devices operating in the reflective mode, the optical path lengths are considerably reduced by employing prism illuminators immediately adjacent the display devices to illuminate the reflective display surface and to spatially separate the incident and reflected illumination. Such color projection systems are easier to arrange and offer sufficient brightness to be useful in both home and commercial applications, such as movie theaters.

Abstract: Power transistors used as high-side power switches are typically subjected to a variety of potentially destructive conditions, such as loss of bias current or loss of a ground connection in associated control circuitry. In order to protect the power transistor upon occurrence of such a potentially destructive condition, a control electrode disable circuit is provided to ensure that the power transistor will be turned off upon the occurrence of such a condition, or when the control circuits are deliberately turned off or placed in a standby mode. Turn-off of the power transistor is ensured by shunting a disable transistor across the input of the power transistor, and providing a disable circuit for activating the disable transistor in the event of loss of bias or loss of ground in the control circuitry. Reliable activation of the disable transistor is ensured by a bootstrap capacitor circuit in the disable circuit.

Abstract: A color projection video system utilizing only a single light valve. A white light source is separated into into red, green and blue bands. Scanning optics cause the RGB bands to be sequentially scanned across a light valve, such as a transmission LCD panel. Prior to each color passing over a given row of panels on the light valve, that row will be addressed, by the display electronics with the appropriate color content of that portion of the image which is being displayed. The image is projected by a projection lens onto a viewing surface, such as a screen. The device includes circuitry to synchronize the illumination of the light valve with the video signal and to minimize video breakup when changing video sources.

Abstract: A color projection video system utilizing only a single light valve. A white light source is separated into red, green and blue bands. Scanning optics in the form of three prisms coaxially mounted for rotation cause the RGB bands to be sequentially scanned across a light valve, such as a transmission LCD panel. Prior to each color passing over a given row of panels on the light valve, that row will be addressed, by the display electronics with the appropriate color content of that portion of the image which is being displayed. The image is projected by a projection lens onto a viewing surface, such as a screen. The sequence of light bands occurs so quickly as to give the viewer an appearance of simultaneous full color.

Abstract: A high pressure discharge lamp includes a pair of arc tubes connected electrically in parallel within an outer envelope, which includes a lamp stem having a pair of stem conductors entering the lamp envelope in a common plane. The arc tubes include conductive feed-throughs at each end thereof. A lamp frame supports the arc tubes in a plane parallel with the stem conductors and is welded directly to each of the feed-throughs with all welds in a common plane with the welds between the frame and the stem conductors. The frame includes a resiliently deformable transverse member which allows for independent changes in length of the arc tubes during lamp operation due to thermal expansion/contraction. The frame is free of slip fit connections with the feed-throughs and free of additional conductive straps connected to the feed-throughs.

Abstract: An electronic high frequency supply, such as a lamp ballast, having a full-wave rectifier, a storage capacitor charged to a voltage greater than the peak of the rectifier output, and an isolating diode between the rectifier and the storage capacitor. An inverter is connected to the storage capacitor, and has a high frequency inductive load circuit connected between the inverter output and a junction between the isolating diode and the bridge rectifier. A capacitor, connected to the junction in parallel with a series circuit formed by the isolating diode and storage capacitor, forms a high frequency resonance circuit with the inductive load circuit. Current is drawn from the rectifier only as a series of pulses at the inverter frequency. To minimize variation in the high frequency load current, the inverter frequency is varied linearly with but oppositely to the instantaneous value of the rectifier output voltage.

Abstract: A video projection system using a light modulating display device having a row and column matrix of picture elements is improved by imparting an oscillatory motion to the display image in the plane of the image, to thereby reduce the visibility of the individual picture elements of the matrix. The resolution of the image can be increased by displaying different video information at different parts of the oscillatory cycle.

Abstract: Video display apparatus having multiple processors for operation in parallel, each processing a respective complete video image in the sequence of video images (fields or frames) which form a video picture, the processing being in accordance with a selected signal processing algorithm. The algorithm may be one which simulates a signal processing circuit design which is to be evaluated, so that the effect of changes in circuit design can be displayed in real time. The signal data for each of the sequential video images is assembled into data packets in successive equal time slots, which are transmitted downstream on a data bus along which are a succession of data processors. The headers of the packets for a given image identify a serially corresponding processor to which such image is assigned, and such packets are processed by the assigned processor in accordance with the selected algorithm.

Abstract: A circuit architecture suitable for use in a television receiver which effectively performs a ghost or echo cancellation procedure on post echo components and pre echo components occurring within the transmission channel. The apparatus features a filter circuit architecture which can be configured under programmed control so as to partition groups of its filter sections to form IIR filters and FIR filters. The filter architecture is suitable for use in multi-circuit configurations and can be used with clustering algorithms to increase the efficiency and optimize the use of the available circuit architecture.

Abstract: The thickness distribution of a vapor deposited layer such as an interference filter deposited on a substrate such as a glass faceplate for a projection television tube, is controlled in the plane of the substrate by employing at least one variable transmission mark to partially shield the substrate during deposition.

Abstract: A genetic algorithm is used to search for optimal configurations of a computer controlled pick and place machine, which places parts on printed circuit boards. Configurations include: assigning grippers to pipettes of the machine; assigning parts, destined for the printed circuit boards, to feeders of the machine; assigning parts to pipettes; and determining time intervals and orders in which parts are to be placed. The genetic algorithm is applied to chromosome strings representing parameters for determining machine configuration. A heuristic layout generator generates machine configurations from the chromosome strings.

Abstract: To prevent light scattering at the edges of CRT's used in projection television, emission of light is prevented beyond a desired region of raster scanning. In one embodiment, portions of the front surfaces of the CRT's outside the desired region are darkened to prevent light emission.

Abstract: A ballast stabilization arrangement is provided for minimizing or eliminating lamp current oscillation, or moding, of gas discharge lamps, such as fluorescent lamps, and a method for carrying out this arrangement is described. This is carried out by adding a frequency response zero to the current circuitry in a ballast. An example of this circuitry includes a feedback network where a sensed lamp current signal is compared with a reference signal by an error amplifier having a resistance placed in series with its feedback capacitance to implement the zero in the frequency response of the control circuit.