Abstract: An improvement to a baseband system having a plurality of down converters feeding a single baseband receiver for assuring the same mean time to intercept while maximizing the probability of intercept as a multi-band, autonomous receiver. All channels of the converter unit are operated simultaneously and a unique tag is added to the output signal from each of the down converters whereby the signal can be identified by the balance of the system as to its associated converter. In one embodiment, the tag comprises an amplitude notch appearing on the output signal at a different time following the receiver threshold being exceeded. In a second embodiment, the tag comprises a frequency step added to and/or subtracted from each output signal at the same time following the exceeding of the receiver threshold. In a third embodiment, the tag comprises a phase shift applied to the output signal.

Abstract: A directional antenna system having a passive arrangement for reducing the amplitude of signals received in the direction of one of the side lobes of the antenna pattern. The system includes a main directional antenna and two or more auxiliary antennas, each of which has less directivity than the main antenna. The auxiliary antennas are aimed in the direction of a selected side lobe of the main antenna whose effect is to be diminished. The outputs of all the antennas are combined in a network having appropriate amplitude and phasing adjustments to cause the combined outputs of the auxiliary antennas to interfere destructively with the energy received by the main antenna in the direction of the selected side lobe.

Abstract: An improved wire grid glass tablet for digitizing graphic information which includes a glass plate with a resin layer bonded to one side and having orthogonal grids of wires, made of a ductile material which is stretched beyond the yield point, embedded in the resin layer near the surface thereof to maximize signal-to-noise ratio coupling to the wires.

Abstract: A liquid toner applicator includes a hollow housing or manifold divided into two channels. A wall of the housing common to both channels is composed of a multi-layer lamination of thin sheet layers, such as etched metal foils. The outermost wall layer constituting the bearing surface for the recording medium is formed with a pattern of slots for applying toner to the exposure surface of the medium. The innermost wall layer is formed with two sets of holes, each set being open to different housing channels. The remaining wall layers between the innermost and outermost layers are each formed with an array of slots or holes which combine and interconnect in the wall lamination to provide a first network of precisely defined toner feed pathways between one of the housing channels and one end of each of the slots in the outermost wall layer and a second network of precisely defined toner recovery pathways between the opposite end of each of the slots in the outermost layer and the other housing channel.

Abstract: A releasable pen block guide for releasably holding the pen block carriage of an X-Y plotter against the track during horizontal traverse movement. A first pair of wheel sets disposed in 90.degree. relationship are rigidly attached to one side of the pen block so as to guide the pen block carriage along the track when held in contact with one of the edges of the track. A pair of second, double, bogey-mounted wheel sets similarly aligned are carried by the pen block carriage and adapted for movement between a first position in contact with the other of the edges of the track and a second position out of contact with the other of the edges of the track and spaced from the first wheel sets sufficiently to allow the pen block carriage to be removed from the track.

Abstract: A user interface device for interfacing with a microprocessor driving a video display. The device is particularly adapted for the use of small children in interfacing with a microprocessor operating to drive a video game or a personal computer. The device comprises a hand puppet adapted to be worn on the user's hand. Pressure-sensitive switches, a light pen, a motion detector, and a speaker are included within the puppet's head and body to allow input by the user through the devices within the puppet and output by the microprocessor at the puppet over the speaker.

Abstract: A pen for use in a graphics plotter employing a turret head with optical scanning of the pens. The upper portion of a cylindrical pen body having a centrally located guide ridge for positioning the pen in the gripping arms is provided with a retaining ridge, a support ridge, and a stop shoulder over which a sleeve is removably snap fit. The sleeve is provided with a reflective tape outer surface heat-bonded to the sleeve.

Abstract: A pen capping mechanism for use in an X, Y graphics plotter, or the like, having a plurality of pens with writing tips requiring sealing between periods of use. A flat bar of plastic is provided as a slider member with an upper surface adapted to sealably mate with the tips of the pens. The slider member is supported for longitudinal movement on a support track and is moved between positions by an operator connected thereto. The member has a plurality of bores therethrough through which respective ones of the pen tips can pass in order to write. The bores are positioned such that as the member is moved through the various operative positions, respective ones of the bores come into alignment with a pen tip such that only one pen tip at a time is in alignment with one of the bores.

Abstract: A slitting apparatus employing safety features and particularly suited for use in slitting strip paper as employed in a graphics drum plotter. A housing is provided which is adapted to be releasably attached to the frame of the plotter adjacent the takeup roller for the strip paper. The housing has a box-shaped top with a hinged opening rear portion. A plurality of knife blades are mounted in housings disposed in a slot in the wall of the box portion for adjustability as to their position along the width of the paper. The knife blades are spring-biased to a retracted position and adjustable actuators in the hinged portion extend the blades selectably only when the box is closed. A releasable latch is provided for holding the box in a closed position. A releasable latching assembly connects the housing to the frame of the plotter. The latching assembly is activated by opening the box which, in turn, retracts the knife blades.

Abstract: A long-life pyrotechnic lamp particularly suited for use in a compact, low-cost laser employing a solid-state laser rod which is pumped by the optical radiation of a pyrotechnic lamp employing the direct combustion of a metal in a flowing oxygen-containing atmosphere. The metal is supported on and heated to ignition by a graphite rod. The metal comprises a cylinder having a centered longitudinal bore adapted to receive the rod therein and has its outer surface serrated or finned to greatly increase the surface area. In one embodiment, the fins are helical about the outer surface. In another embodiment, the outer surface of the metal is longitudinally slit. In both cases, the metal is subsequently sliced into segments.

Abstract: A high-frequency, high-power generator of the type in which energy is stored in the capacitance of a transmission line and then discharged into a load by the action of a spark discharge device. The load is connected between one end of a transmission line conductor and ground and the other end of the same conductor is grounded. The line is folded and both ends of the other transmission line conductor are connected to the spark discharge device. A charging circuit applies a voltage to the latter conductor and when it reaches the discharge potential of the spark discharge device, the latter discharges to connect both ends of that conductor to ground. This provides relatively well-defined positive and negative pulses to the load.

Abstract: An electronic writing pen which induces electromagnetic signals in conductors which are disposed in a writing table and are connected to digitizer circuitry is disclosed. The pen has a writing cartridge which is movable within the pen housing and includes, in one embodiment, a thin, deformable, stainless steel dome switch element which functions as an electrical contact in a normally-open switch which is utilized to provide an electrical indication of the up/down status of the pen to the digitizer and tactile feel of change of pen position to the pen user. In another embodiment, the switch includes an insulating strip having a conductive layer thereon to provide status indication with low application of force to the pen and without tactile feel.

Abstract: A microwave antenna is made of a pair of parallel ground-plane conductors (12 and 14), one of which forms a generally cruciform aperture (18). A pair of T-shaped feedlines are disposed with their cross pieces (22 and 34) in registration with the respective arms (20 and 36) of the aperture 18 and are independently driven from stems (26 and 32) disposed between the ground-plane conductors.

Abstract: Apparatus for assisting in the loading of strip roll paper in a graphics drum plotter having a vacuum column disposed between a strip paper supply roller and a drum wherein insufficient space is available between the drum and the beam/writing head above it for reaching through to grasp the paper on the supply roller for pulling it through. A hook-shaped wire guide is hingedly attached through a slot in the center of the back wall of the vacuum column. The guide wire is biased by a counter weight to a position within the vacuum column and is moved out of the vacuum column through the slot from the force of paper descending into the vacuum column. The hook is shaped to guide paper being rolled off the supply roller across the space between the front and back walls of the vacuum column and to direct it into a position between the drum and the beam/writing head where it can be grasped.

Abstract: An optical radar is disclosed in which fine vernier range and angular displacement accuracy is achieved by projecting a burst of coherent pulses so as to strobe a target passing through the field of view of the projection apparatus. The use of the pulse burst permits the most recent information to be utilized in obtaining the target track. Prior to projection, the pulses in the burst are sampled. The resulting signal is delayed by an amount corresponding to course range and is directed down one of a pair of oppositely directed delay lines. The signals returned from the target are detected by a sectorized receiver, with an electrical output signal from a detector in one of the sectors being applied to the other delay line in the corresponding pair, such that the signal corresponding to the returned pulse propagates in a direction opposite to that of the sampled signal corresponding to the transmitted pulse.

Abstract: A turret head for use in a graphics plotter for holding a plurality of liquid ink pens adjacent the point of writing and for selectively changing the pens to be the writing pen. Automatic pen tip capping and uncapping is included. A plurality of spaced radial arms are mounted on a turret driven by a stepping motor between main positions. A pen holder assembly is mounted for vertical movement between raised and lowered positions and carries a pen gripping arm thereon. The pen gripping arm is adapted to move vertically between the radial arms of the turret and beneath them as the turret is rotated. The arms are provided with facing releasable gripping fingers for exchanging pens between arms upon contact.

Abstract: Control is provided to conventional gun-fired projectiles by substituting for the standard fuze thereof a device comprising a canard frame and a main housing, which threads into the fuze well of the projectile, with the canard frame being rotatable with respect to the main housing and having deflectable canards thereon for providing vernier correction on the trajectory to the projectile.

Abstract: A convertible platen for use in a graphics plotter to allow its selective use as either a cut paper plotter or a roll paper plotter. The platen is formed from a specially designed aluminum extrusion and a pair is mounted with one on either side of the drum of a drum plotter between the drum and the supply/takeup rollers. The platens can be raised and held adjacent the drum and spanning the vacuum columns in the plotter to create a table having curved outer edges to support cut paper. They can be released and dropped into the vacuum columns whereby they lie against the outer surfaces and form the upper inner wall with curved upper edges over which paper smoothly is guided between the vacuum columns and the supply/takeup rollers.

Abstract: An improved wire grid glass tablet for digitizing graphic information which includes a glass plate with a resin layer bonded to one side and having orthogonal grids of wires, made of a ductile material which is stretched beyond the yield point, embedded in the resin layer near the surface thereof to maximize signal-to-noise ratio coupling to the wires.

Abstract: LORAN-C navigation apparatus is disclosed wherein digital circuitry and a microprocessor .[.is.]. .Iadd.are .Iaddend.used to automatically identify LORAN transmitting stations and .[.makes.]. .Iadd.make .Iaddend.standard hyberbolic navigation measurements. The equipment operator manually enters the group repetition rate into the apparatus for a LORAN-C chain covering the area within which the navigation apparatus is being operated. Initially, the apparatus searches all incoming signals .Iadd.as they are received .Iaddend.until signals from a master station are received regularly at the stored group repetition rate.