Abstract: A device for determining the frequency range and chirp rate of chirp radars or other sources of frequency-modulated signals includes a compressive receiver (16, 22, 24) for time-compressing single-frequency signals and a discriminator (26) for generating an output that represents the instantaneous frequency of the compressive-receiver output. For narrow-band signals, the frequency-modulated components in the output of the compressive receiver do not last long enough to cause a response from the discriminator (26). When the input of the compressive receiver is a chirp signal, on the other hand, the resultant compressive-receiver output lasts long enough to cause a discriminator response, and its time of occurrence and rate of frequency change are indications of the frequency range and chirp rate of the compressive-receiver input. The discriminator (26) accordingly generates an output whose slope is an indication of the chirp rate of the compressive-receiver input.

Abstract: A multicolor electrostatic plotter is disclosed and includes an image head for imparting a charge pattern to a web medium to be imprinted and a plurality of toner means associated with different colors in which different colors are successively applied to portions of the medium by repeatedly driving and rewinding a portion of the medium past the image head and the plurality of toner means for charge and toner application to imprint multiple color rasterized images on the medium by the use of electronic circuitry which imprints a reference track on the medium during the first color pass and then optoelectronically detects deviations, generally perpendicular to the directional movement of the medium, of the medium during successive color passes substantially instantaneously with the deviations and which electronically adjusts the input data from a remote rasterizer by an amount equal to the substantially instantaneous offset so that lines of raster data are shifted by an amount substantially equal to the instan

Abstract: A simulator for simulating the response of a network of predefined processing elements to a set of input stimuli. The network processing elements are arrayed in a plurality of rows and columns and a representation of each element is stored in a storage location in a symbol memory, the storage locations of which have row and column addresses corresponding to the rows and columns in the network array. A control circuit iteratively receives representations from the symbol memory identifying a processing element at a location in the network and controls an arithmetic and logic unit to generate an output signal representative of the output of the corresponding processing element in response to input stimuli which are represented by data signals from a data memory and an intermediate storage register. The control circuit then controls the storage of the output signal from the arithmetic and logic unit in the data memory and the intermediate storage register.

Abstract: A pneumatic time delay valve primarily adapted for use in the ejection system of electronic or optical countermeasure devices and the like wherein an explosive squib is employed to create a momentary charge of high pressure gas used to depress the firing pin on the device to activate the device and also to push the device out of an ejection tube. The invention comprises means for splitting the pressurized gas into a first conduit communicating with the firing pin and a second conduit communicating with the device to apply the ejection pressure thereon and a time delay valve disposed within the second conduit for delaying the application of the gas to the device. During the time delay period, a piston is forced down a cylindrical bore forcing metering fluid through an orifice.

Abstract: A circuit is provided which receives pixel data and pixel addresses from a graphics processor and effectuates rapid clipping of image information lying outside of a corresponding window, and also provides a template memory for storing information corresponding to all areas of that window which are obscured by a higher priority window. The pixel addresses are simultaneously applied to an image memory, the template memory, and the window clipping circuit. A write control circuit enables a write signal produced by the graphics processor to be applied to a write input of the image memory only if the present pixel is located within the present window, as determined by the window clipping circuit, and is not in an obscured area of that window, as determined by the read-out of the template memory.

Abstract: An optical system to permit two detectors to see the same field of view includes an angle converting cone, for mixing radiation from a field of view so that it can be applied to two detectors, and a lens for focusing the radiation onto the cone.

Abstract: A vertically polarized omnidirectional antenna adapted for use in airborne, Very High Frequency (VHF) applications is disclosed. The antenna is configured as a conductive patch spaced over its virtual image. The addition of a number of switching devices allows operation over a five-to-one bandwidth while maintaining a two-to-one Voltage Standing Wave Ratio.

Abstract: An assembly for positioning a print head so as to transfer ink from an ink ribbon to a printing medium positioned on a movable platen adjacent to said ribbon supports the print head on a rocker member which enables the head to be swung between a print position wherein it engages the ink ribbon and a feed position wherein the head is spaced from the ribbon enabling ribbon to be moved. The rocker is rocked to move the head between its two positions by a rotary cam driven by a small low-power electric motor. When the cam engages the rocker member at selected angular positions, the head is maintained in its retracted feed position; otherwise, the head resides in its print position. The assembly also includes provision for detecting the angular position of the cam so as to produce signals to facilitate repositioning the cam and head promptly.

Abstract: The invention concerns an application of linear system parameter estimation techniques to finite amplitude sonar devices, to extract fine grained angular position information about echo sources. The invention makes use of the fact that the waveform return by a reflecting object within the sonar's beam varies according to its relative angular position from the receiver, and a discovery that this variation may be fit to a linear system model using autoregressive estimation theory to extract the nature of the variation. In all cases, the information is extracted without the mechanical or electrical steering of the sonar transmitting beam.

Abstract: A surveillance system for simultaneously identifying the directions and frequencies of a plurality of electromagnetic-radiation sources includes an irregular array (10) of antenna elements and employs a two-dimensional compressive receiver (14) that receives at its input ports (18) the individual element signals. Each output of the two-dimensional compressive receiver (14) is modulated in an associated modulator (20) by one signal of a composite ensemble of signals. The composite ensemble is the sum of a plurality of individual ensembles, each of which is an ensemble of signals of a frequency uniquely associated with that individual ensemble and individually modulated to favor a direction associated with that individual ensemble. The results are added together in summation circuit 22 and applied to a Bragg cell (24), which segregates the results of modulation by the individual ensembles.

Abstract: A laser which discriminates against a high gain transition in laser materials allowing a low gain transition to oscillate is provided by using more than two mirrors in the laser cavity which are highly reflective at the frequency of the high gain transition.

Abstract: A method and apparatus for simulating a network comprising a plurality of processing elements useful in simulating, for example, complex digital combinatorial electronic logic circuits. Each type of digital logic element is assigned a symbol, and the symbols are stored in an array pattern in a memory, with the row and column addresses of the symbols in memory corresponding to their position in the network. The simulator sequentially retrieves each element in the network starting from an input and determines the element response to an input signal based on the type of element and the signals input to it. After all of the elements in the network have been processed, the simulated output of the network is available at the network output elements.

Abstract: An optical power distribution system for supplying power to low power electrical devices includes an electrically powered source of optical radiation the output of which is applied to a photovoltaic cell array arranged on the device to be powered and electrically connected thereto.

Abstract: A cutter assembly (82) for cutting web material such as paper (80) includes a circular cutter (100) having an endless peripheral blade (102) mounted on a frame (92) on which also is mounted a tension roller in the form of a pulley (94). A smaller pulley (98) is mounted on and co-axial with the circular cutter 100, and a belt (96) is trained around the pulleys (94 and 98). The portion of the belt (96) on the tension roller (94) provides an engagement surface adapted to engage the paper (80) so that movement of the cutter assembly (82) causes rotation of the tension roller (94) and thus faster rotation of the circular cutter (100). This results in efficient cutting of the paper (80) and high cut quality because the tension roller (94) prevents bunching of the paper (80) in the vicinity of the endless blade (102).

Abstract: A decimation-in-frequency fast-Fourier-transform butterfly circuit for performing a radix-four butterfly operation includes a first group of adders (86, 88, 90, and 92), a second group of adders (70, 72, 74, and 76), and a group of twiddle-factor multipliers (78, 80, and 82) that are interconnected in such a way as to perform the radix-four fast-Fourier-transform algorithm. Additionally, bypass lines (102, 104, 106, and 108) bypass the first group of adders, and switches (94, 96, 98, and 100) switch between the signals on the bypass lines and those from the first group of adders. As a result, the circuit performs a radix-four FFT operation when the switches are in one state, and it performs two radix-two FFT butterfly operations simultaneously when the switches are in the other state.

Abstract: A signal source in the general form of a phase-locked loop (12, 20, 22, and 24) has its output fed to a phase modulator (32) controlled in response to the output of the phase-locked-loop phase detector (20). This provides feed-forward error correction that gives the signal source a faster response than a conventional phase-locked-loop arrangement would have.

Abstract: An optically pumped solid-state laser system includes a rod (50) of laser material and a plurality of flashlamps (66) for pumping the laser. A surface for reflecting radiation from the flashlamp (66) to the rod (50) follows a set of curves (96). Each curve (96) is the locus of points whose distances outside the rod (50) and the lamp (66) to a pair of starting points on the other side of a base line (74) are a constant value such that the locus includes a lamp cusp (70).

Abstract: A control system for controlling a turret head in a pen plotter wherein the turret head and pen holder move in combination with the pen carriage to provide turret selectability at the writing site. Sensors and associated logic are provided for detecting the presence of a turret on the pen carriage, for sensing the presence and absence of pens in the turret and in the pen holder, for detecting the type of pen or other writing device being used and taking appropriate action responsive thereto, and for applying varible damping constants to the movement of the turret head. Control logic is disclosed for assuring reliable and optimum operation.

Abstract: An interactive simulation system for simulating an analog or a digital system defined by mathematical model representing the operation of the system. The mathematical model is represented by a network of function blocks specified by an operator, each function block providing an output corresponding to a primitive mathematical or logical operation on an input. The system iteratively steps through the network to simulate the system at sequential points in time. At least some of the function blocks represent delay functions in which their outputs are in response to the inputs during the previous iteration. The simulation system first receives from an operator the identification of the function blocks to be used in the network, the function blocks being entered from the input of the network to the output, except that any delay blocks are entered last.

Abstract: A user-friendly ribbon cartridge to house and to facilitate handling a wide thermal transfer ribbon for a thermal color printer is composed of first and second casing sections which define a slotted let-off tube and a slotted take-up tube and turnbar. A pair of casing end pieces connect the corresponding ends of the casing sections so that they are juxtaposed with their axes parallel to one another so as to define a plane and the turnbar is spaced parallel to that plane so that a stretch of ribbon wound about cores rotatively mounted in the tubes can extend out through the tube slots and over the turnbar creating a large unobstructed planar ribbon area that is accessible from both sides for printing. A handle and latch member integral to one of the end pieces facilitate positioning the cartridge properly in the associated printing apparatus and locking it in place during printing.