Abstract: An error amplifier receives an on/off signal and supplies an error signal to an integrator. The latter provides a ramp output, which is fed back to the error amplifier whereby the error signal therefrom further is dependent upon the ramp output. The error signal is selectively clamped positively and negatively whereby the resulting ramp output has a constant ramp time, with no ramp on/off delay.

Abstract: An improved control apparatus and method for servo system control is disclosed wherein a generally increasing or decreasing control signal is supplied to a source of energy when a desired parameter of interest produced by said source of energy is not equal to a desired value, and a constant control signal when the parameter of interest does equal the desired value. The constant control signal is determined by the previous constant control signal plus the product of the difference between the peak value of the generally increasing or decreasing control signal and the previous constant control signal multiplied by a constant.

Abstract: A supply reel servo for a tape transport in which a motor-driven capstan of low inertia draws tape past a cylindrical scanning drum includes a tension servo arm which provides a signal denoting tape tension in a loop adjacent the supply reel. This signal is compared with a reference to develop an error signal to control the supply reel motor. The reference is modified in response to a signal which represents the energization of the capstan motor and accordingly the torque output thereof so as to provide automatic compensation for variation in tape tension at the scanning drum.

Abstract: An operator is provided with a continuous display, on a single convenient monitor, of the extent of progress, the status, etc., of each camera in a multi-camera system, during a microprocessor controlled automatic setup procedure. The display is superimposed on a video picture generated by the selected camera, which corresponds to one of various video signals selectable by the operator.

Abstract: The scanning process of a television camera is modified so that scanning is inhibited for N successive scan periods and is enabled during the next scan period, in a repeating cycle of (N+1) periods duration. The signal output generated during the N inhibited scan periods is zero but, during the enabled scan period, is (N+1) times greater than the corresponding signal which would be generated by conventional scanning action.

Abstract: An auto chroma filter averages the value of successive color burst amplitudes on a line-by-line basis over many video frames, by fetching a burst value from memory and loading it into an up/down counter, and also into a D/A converter which provides the chroma filter output signal. A comparator compares an incoming new burst value with the output signal, whereby the counter increments or decrements the value toward the incoming new burst value in response to the comparator. The updated value then is loaded back into memory in the same location from which it was fetched, and the cycle continues for each video line and successive frames.

Abstract: A power fail circuit provides protection for tape such as used in the tape transport apparatus of a video recorder in the event of a failure of the external power supply. The tape transport apparatus includes as a feature the provision of an electrical error signal used to govern drive motors to maintain substantially constant tape tension when the system is operating normally. After power failure occurs, the power fail circuit continues to respond to the error signal by coupling current from the drive motors to provide dynamic braking. Further, current taken from the drive motors selectively is coupled to an energy storage device operatively associated with the system power supply, to provide augmenting energy from the kinetic energy of the motors for continued control of the power fail circuit as the drive motors are caused to decelerate under control to stop.

Abstract: Vertical-rate and horizontal-rate sawtooth generators are coupled at a common input to a conventional focus control voltage and then to the centering circuits of an image tube via respective potentiometers. The amplitudes and polarities of the generator outputs are selected such that when driven simultaneously by the electrical focus control voltage supplied to an image tube, generates an image rotation which just cancels any image rotational error inherently induced by an electrical focus adjustment.

Abstract: One or more input signals to be processed are summed with a pseudo random noise signal to preserve the signal phase, are placed on a carrier, are processed by a one-dimensional optical spectrum analyzer, and a time history thereof is stored in a digital corner-turn memory in a time/frequency domain. The memory is read with an address map that corner-turns the stored data, where the resulting frequency/time signal then is fed to a second one-dimensional optical spectrum analyzer. Since signal phase is preserved, a two-dimensional analog signal in a frequency/frequency plane is provided.

Abstract: A change in direction of a moving member is detected on the first edge of a quadrature tach pulse which is out of a given sequence, and a clock pulse is supplied whose rising edge always occurs after the direction change.

Abstract: A digital chrominance signal in a digital component television system is digitally filtered to obtain sampling values intermediate the sampled values obtained during analog to digital conversion of the chrominance signal, such that the resultant number of chrominance samples per second in the digitized chrominance signal corresponds with the number of luminance samples per second in the digitized luminance signal. The samples values of the digitized chrominance signal including the computed intermediate values may also be modified by said digitized filter to minimize the alias created by the analog to digital correction sampling process, to compensate this signal for sine x/x losses existing in the digitized chrominance signal, to compensate for Gaussian filter attenuation of the chrominance signal prior to analog to digital conversion thereof, and to compensate for other deficiencies in the chrominance signal.

Abstract: A pattern recognition circuit integral with a checkerboard diascope pattern used for spatial and shading error measurement and correction, performs detection in the time domain. A locator time window is provided to positively locate and distinguish white-to-black transitions of coarse locators selectively placed within the diascope pattern from, for example, checker white-to-black transitions, or from white-to-grey transitions, even under adverse scanning conditions. The circuit includes narrow time windows for identifying specific valid locator transitions, to thereby prevent triggering due to checker transitions, short noise pulses, etc. During one field interval, each locator is scanned a number of lines, but only the middle line scan is used to describe the locator coordinates, i.e., is used to generate a locator strobe output for latching the coarse locator positions into a system memory for subsequent comparison with the diascope pattern to determine the coarse scan errors.

Abstract: Selected additional voltages are utilized to modify the respective horizontal and vertical sawtooth waveforms which generate the horizontal and vertical electron beam scans in a photoelectric tube. The added voltages are selectively applied during the respective horizontal and vertical blanking intervals, whereby the speed of the scan is doubled, tripled, etc., during the blanking intervals. Since the time available during blanking is still the same, increasing the speed of the beam scan causes the beam to scan correspondingly further into the non-scanned target portion. Thus, corresponding greater distances into the surrounding target are discharged which, in turn, circumvents charge bleeding into the active picture area, thereby precluding edge hooking.

Abstract: An open loop tension servo uses digital circuitry to automatically control motor torque and thus tape tension in, for example, a tape recorder, without the need for a tension sensor. To this end, the tape pack diameter of a tape takeup or supply reel is digitally computed, thus determining the motor torque required to maintain the requisite tension on the tape during the record or replay operating mode. A binary number indicative of the instantaneous tape pack diameter is generated and stored until a new number is available. Each stored number is supplied to D/A converter means formed of selected parallel or series resistor, arrays, wherein specific resistor combinations are successively selected to provide a corresponding change in resistance commensurate with the changing pack diameter represented by the changing size of the binary number.

Abstract: Conventional border, drop shadow and/or matte outline generating signals are selectively gated through an offset amplifier of less than unity gain and then fed back into the existing delay lines, to selectively modify the horizontal and vertical trailing edge of the waveform generated by the loop, which, in turn, modifies accordingly the selectively switched composite video signal, i.e., provides for selectively increasing the size and/or varying the configuration of the luminance key signals.

Abstract: A circuit for suppressing the effects of excessive highlights is automatically enabled in response to highlights in the viewed scene which exceed a given threshold. The circuit is used in combination with a special pickup tube or tubes which include excessive highlight protection elements and a corresponding mode of operation. The circuit allows the continuous operation of the pickup tubes with improved resolution at a heretofore prohibitive, but preferred, high voltage level (e.g., 950 volts), rather than the generally accepted and recommended operating level (e.g., 750 volts) therefor, while prolonging the lifetime of such tubes. Detector means generates the circuit enable signal in response to the presence of highlights in excess of the given threshold. Control circuit means are conditioned thereby to drive the tube into the corresponding mode of operation during the line flyback period corresponding to the horizontal blanking interval.

Abstract: A hologram, produced by illuminating an object via a coherent light source and associated optics, or by digital components or photographic components, is imaged onto, for example, a television camera to selectively provide either a real time, or a non-real time, system. When written directly onto the camera, the hologram is used in a real time system, whereas the digital or film input to the camera provides the combination for a non-real time system. The image is converted into a corresponding electrical video signal via the camera, and the signal is supplied to a selected spatial light modulator. Subsequent illumination by a read coherent light source reconstructs the hologram into a three-dimensional image of the original subject matter, which then may be viewed via a selected optics system.

Abstract: In this controlled decay envelope detector, a capacitor is used to hold the momentary peaks of the input signal. Its only discharge current path is controlled by a circuit which simultaneously monitors the capacitor voltage and the input signal such that the discharge current from the capacitor is proportional to the voltage difference between the capacitor voltage and a conventional exponential RC decay voltage provided in the control circuit. The resulting discharge from the capacitor, in response to a negative-going step input voltage, is an increasing current starting from zero at the time of the transient. The resulting detector output describes an upwardly convexing voltage decay curve which holds its level essentially equal to that of the initial peak input voltage until the next estimated peak input occurs. Only when the next peak input does not come, or is lower than the last one, will the output start dropping at an increasing rate, which provides a correspondingly precise detection of the envelope.

Abstract: The phase of an output subcarrier signal may be varied over a range of 360.degree. with respect to the phase of an input subcarrier signal. A ramp generator which generates a ramp at one-half the subcarrier frequency, is coupled to a very fast differential comparator means whose output causes a subsequent tuned circuit to ring at the subcarrier frequency. Continuous oscillations, recycled every second subcarrier cycle, are generated as determined by the threshold set on the differential comparator means. A crystal filter reproduces the output subcarrier as a clean sinewave. Remotely controlled phase adjustment of from zero to 360.degree. is provided by varying the threshold of the differential comparator.

Abstract: A method and apparatus for measuring vertical surface variations of a specimen is disclosed wherein the specimen is mounted in movable relation to an objective lens assembly, a reticule being arranged at a focal plane of the objective lens assembly, movement between the objective assembly and the specimen necessary for maintaining the reticule in focus upon different surface portions of the specimen providing an indication of vertical spacing between the surface portions. Another embodiment of the invention contemplates a three-dimensional reticule arranged at or adjacent a focal plane of an objective lens assembly for simultaneously focusing portions of the reticule upon different surface portions of the specimen, the reticule being adapted to provide an indication that the vertical spacing between the different surface portions of the specimen is within acceptable limits.