Abstract: Incoming data from one of two data channels is coupled through a multiplexer to a ping pong memory. While data is being read into one section of the ping pong memory from the data processing equipment, it is being read out of the other side of the ping pong memory. Since part of the header information constitutes marks and spaces, i.e., groupings of all ones or all zeros, if a data word contains all ones, it could be misconstrued. Therefore, any data word which contains all ones is converted to a data word which is one bit less than all ones. Once this conditioning is done, of each group of 13 input words, each word representing a pixel and each word being ten bits long, the first, fifth, and ninth words are extracted using programmable logic arrays. The 30 bits obtained by this extraction are broken down and appended, in groups of three, to the existing bits of the remaining ten words of each group of 13 input words.

Abstract: Four pairs of paper drive rollers are provided which may be individually adjusted so that proper balancing of the bite pressures result. The same springs employed for this purpose are also utilized to maintain the mechanism locked and to provide rapid and easy opening of the mechanism to widely separate the rollers for the purpose of cleaning and preventing the rollers from being flattened due to continued application of bite pressure when the machine is not being used.

Abstract: A method of fabricating a controlled harmonic grating having both binary magnitude and phase transmissions in which specified harmonics are enhanced and/or suppressed. The summing of a number of binary pulse trains produces a controlled harmonic grating transmission function. The binary grating is readily fabricated by applying strips of light blocking material corresponding to the occurrence of a zero value of the transmission function, and by forming light-transmissive strips coincident with the portions of the transmission function having an absolute value of 1. Strips of phase retarding material are also deposited having a relative phase shift of pi radians.

Abstract: The invention provides a means for determining rapidly and accurately frequency information of electromagnetic radiation. It combines the operation of an Instantaneous Frequency Measurement receiver with the operation of an Instantaneous Fourier Transform receiver which utilizes a Laser-Bragg cell-photodetector array. The operational characteristics of the two receivers are such that, when they are controlled by signal processing elements, including a programmable frequency memory screen to enable or inhibit data transfers, they complement each other to provide the combined advantages of both receiver types, namely broad RF bandwidth, rapid response, ability to deal with high pulse densities, multiple CW signals, combined CW and pulse signals. The complementary IFM/IFT system operates under conditions for which either receiver operating separately would fail.

Abstract: A silicon wafer is provided which does not employ individually bonded leads between the IR sensitive elements and the input stages of multiplexers. The wafer is first coated with lead selenide in a first detector array area and is thereafter coated with lead sulfide within a second detector array area. The described steps result in the direct chemical deposition of lead selenide and lead sulfide upon the silicon wafer to eliminate individual wire bonding, bumping, flip chipping, planar interconnecting methods of connecting detector array elements to silicon chip circuitry, e.g., multiplexers, to enable easy fabrication of very long arrays. The electrode structure employed, produces an increase in the electrical field gradient between the electrodes for a given volume of detector material, relative to conventional electrode configurations.

Abstract: First and second rotatable edge guide rollers are provided having precision roller positioning means for preventing skewing of sheets of predetermined widths, such rollers being laterally shifted in position to accommodate various widths by means of a roller actuation device which controls a counter which counts the extent of travel of a recording head between a reference position and a position indicative of the guide roller position. The count within the counter is examined by logic circuitry which determines whether the rollers are properly positioned across the width of sheets. The sheet reference platen has a plurality of apertures which receive a fiducial referencing projection mounted upon the roller actuation device and when the actuation device and hence the roller is in one of the predetermined positions the projection device will pass through a particular aperture to permit the sheet referencing platen to be lowered into position.

Abstract: Groups of electromechanical actuators affixed to a movable mirror are coupled to the mirror along radial lines extending from the central portion thereof. The actuators in each of such groups have variable sensitivity of mechanical response per volt applied, such sensitivity increasing for each actuator which is positioned further and further away from the central portion, and thus for any desired motion, only one control voltage is required to drive all actuators in a particular group. Variable sensitivity is preferably attained by constructing all actuators to have the same number of piezo-electric layers and connecting more and more electrodes associated with the layers to the single control voltage for actuators positioned further and further away from the central portion of the optical element.

Abstract: Apparatus for measuring the velocity of a moving image or object including a first array of sensors extending in a first direction transverse to image motion for sensing a primary set of image elements; a second array of sensors extending generally in the first direction and spaced a known distance from the first array for sensing successive sets of image elements; a device for correlating the primary set of image elements with each of the successive sets of image elements and for producing a correlation level indicating the level of correlation of the primary set with each of the successive sets; means for selecting one of the correlation levels which indicates an optimal level of correlation; and means for determining the time interval between the sensing of the first array of the primary set and the sensing by the second array of the successive set corresponding to the selected correlation level; in addition, the means for correlating may include means for comparing with the primary set each successive set

Abstract: An automatic printed wiring board (PWB) defect detector is described. The detector comprises an array of optical sensors for optically inspecting a printed wire circuit. The array forms a binary image pattern of the PWB which is tested for compliance with logical rules of correctly printed PWB's regarding unterminated conductors; minimum specified lined width; line spacing width; presence of insulators on conductors and vice versa; and maximum line width. The detector comprises a plurality of CCD arrays arranged to form a series of pixels consisting of electronic binary signals corresponding to the instantaneous image viewed by each element in the CCD array. These pixels are formed in an image data stream of sequential pixels line-by-line of the CCD array, i.e., pixel sequential line sequential digital image data. The digital pixel data is formatted in an "N" by "N" bit matrix of points in proper image orientation. All such points are available for sampling.

Abstract: A wavefront sensor employs a novel DC shearing interferometer which produces four interferograms which are 90.degree. phase shifted with respect to each other. The incoming wavefront is replicated into two beams, a portion of each being reflected off of a beamsplitter and the remaining portion being transmitted therethrough, at first and second portions of the beamsplitter. After leaving the beamsplitter the transmitted and reflected beams are reflected back 180.degree. by a pair of retroreflectors, and directed at third and fourth portions of the beamsplitter. The retroreflectors are adjusted to produce four shearing interferograms and a quarter wave plate is positioned in the path of one of the beams to cause the four interferograms to have a 90.degree. phase shifted relationship with respect to each other.

Abstract: Apparatus and method for encoding and decoding a signal which is divided into a plurality of signal lines, each of which is a successive line of pixel signal values taken from a two-dimensional informational field. The apparatus for encoding includes the following elements: means for deriving a neighborhood value representing the pixel signal values taken from the two-dimensional field in the neighborhood of a pixel signal value to be encoded, which neighborhood value is based, at least in part, on a pixel signal value in another signal line than that in which the pixel signal value to be encoded is located: means for deriving the difference between the neighborhood value and the pixel signal value to be encoded; and means for outputting the difference as the encoded representation of the pixel signal value to be encoded.

Abstract: A long period buried optical grating is fabricated by polishing a number of single crystal silicon wafers to identical thicknesses and flat figure, applying a light reflective metallic coating to the wafers, thereafter bonding the wafers together in a stack, and thereafter lapping the resulting stack of bonded layers at an acute angle with respect to the major planar surfaces of the wafers to form the buried grating, such grating having optically flat reflective sawtoothed elements. The grating period may be readily controlled by changing the acute angle and/or the thickness of the silicon wafers.

Abstract: A simple, reliable heater-fuser station for fusing toner images upon relatively stiff, resilient and moist printing plates includes a curved heater-platen positioned between a pair of entrance squeegee rollers and a pair of exit rollers. The angles between the plate material and the surfaces of the heater-platen due to roller orientations are such that the high beam strength and resiliency characteristics of the wet plates are advantageously employed to maintain intimate contact between the leading and trailing edge portions, as well as centralized portions, of the plates and the heater-platen.

Abstract: A first apertured shutter rotates almost a full revolution in a first direction, and a second apertured rotary shutter rotates almost a full revolution in an opposite direction before the apertures of both blades are present at the optical axis to effect exposure, thereby to reduce dynamic disturbances owing to the reduced blade accelerations required.

Abstract: An array of electromechanical actuators are positioned beneath a movable mirror and have movable contacts which are affixed to the upper surface of a resistive mat having a single voltage gradient applied across the mat to control the tilting of the mirror. The adjustability of the contact points of each actuator enables the use of actuators which have a substantially varying sensitivity with respect to the application of particular voltages.

Abstract: Circuitry for converting interlaced video data to non-interlaced video data at 30 frames per second, real time video rate, where rows of successive lines of video data applied to a single frame memory are provided having data control means including readin and readout means for initially sequentially loading each row of memory with lines of interlaced video data of the first frame sequentially applied to the memory and thereafter reading out successive memory rows of the first frame from memory, while replacing each line readout by whatever line of the second frame is applied to memory in real time just after readout, until all lines of data of the second frame are inserted into memory.

Abstract: A technique for reproducing an image in a set of grey scale steps is disclosed including: providing a plurality of superpixels for providing an output representative of an image; providing a set of threshold levels for each pixel in a superpixel, which set is different from each of the sets of threshold levels of the other pixels in that superpixel and different from the set of greyscale steps; identifying the position of a given pixel in a superpixel and designating a particular set of threshold levels corresponding to the position of that given pixel; comparing the output of the given pixel with its particular set of threshold levels; and indicating the greyscale step in the set of greyscale steps in response to the output of the given pixel equal to or in excess of at least one of the threshold levels in the set of threshold levels corresponding to that pixel position.

Abstract: A sensitive wavefront sensor combining attributes of both a Hartmann type of wavefront sensor and an AC shearing interferometer type of wavefront sensor. An incident wavefront, the slope of which is to be detected, is focussed to first and second focal points at which first and second diffraction gratings are positioned to shear and modulate the wavefront, which then diverges therefrom. The diffraction patterns of the first and second gratings are positioned substantially orthogonal to each other to shear the wavefront in two directions to produce two dimensional wavefront slope data for the AC shearing interferometer portion of the wavefront sensor. First and second dividing optical systems are positioned in the two diverging wavefronts to divide the sheared wavefront into an array of subapertures and also to focus the wavefront in each subaperture to a focal point.

Abstract: An optical data recording system and method for receiving an input data stream to be recorded on a recording medium; dividing the input data stream into a series of data sections; compressing each data section in the series into a period shorter than the period of the original section and providing data gaps between each compressed data section; recombining the compressed data sections including the data gaps into a gapped output data stream; and recording the gapped output data stream on a recording medium.

Abstract: A beamformer device for forming at least one beam from the outputs of a sensor array, including: a plurality of radiation sources; means for providing to each radiation source a signal from an associated one of the sensors in the sensor array; a detector array of radiation-sensitive means for providing a series of spaced signals representing radiation incident from each of the radiation sources; and means for varying the delays between the spaced signals for optimizing the response of the device to a signal from a predetermined direction.