Abstract: A switched RF signal, formed of modulated RF and blanking level signals, is selectively phase inverted on alternate pairs of television lines to provide, after FM detection, a video signal containing alternating positive and negative offset errors. The video signal is integrated to average and thus, in effect, minimize the alternating errors.

Abstract: An improved clock recovery system for use in digital rotary scan magnetic playback devices utilizing a phase locked loop. The clock signal recovered from the playback data has a phase error with a periodic component caused by time base variations in the playback data and a random noise component due to playback channel noise. The phase locked loop of the invention tracks the periodic component, while it suppresses the random noise component. The improved system is suitable for tracking wide bandwidth dynamic time base variations in the playback data without introducing phase errors caused by random noise into the recovered clock signal.

Abstract: A plurality of magnetic blocks is integrally joined side-by-side with a nonmagnetic material therebetween to provide a monolithic block defining parallel transducing gap planes, each pertaining to one multichannel transducer stack. A plurality of first parallel slots in the monolithic block intersects the gap planes to define a plurality of partitions, each partition forming pairs of magnetic pole pieces defining respective transducing gaps pertaining to respective stacks. The transducing gaps of each partition define interlaced transducing channels of the multichannel assembly. Second parallel slots provided along the gap planes have apexes defining transducing gap depths. The resulting transducing channels have uniform gap azimuth and gap depth while uniform internal stack alignment between all the respective stacks is obtained.

Abstract: An arrangement for a linear motor which uses a shorted turn as a shield for the magnet of the motor to thus provide a substantial reduction in the introduction of particulate matter into the Head Disk Assembly environment associated with the linear motor, without substantially increasing the reluctance of the magnetic circuit of the motor.

Abstract: A video transformation and filtering system generates for each source image data point a plurality of target image addresses indicating a displacement between a point at which the source image data point maps into the target image and each data point of the target image which is affected by the source image data point. By providing either sequentially or in parallel a separate processing for each target image data point that is affected by a current source image data point values for all of the target image data points can be generated from a single pass of the source image data points. By effectively providing the filtering in the domain of the target image instead of the source image a single filter function with a fixed number of points in the target image domain can be used to attain low pass filtering of the resulting target image irrespective of the degree of size compression of the video image.

Abstract: For each magnitude of charge stored on a section of a target of a photoelectric tube due to the action of incident light thereon, there is a specific value of cathode voltage which ensures the discharge of the section in one pass of the scanning beam. It follows that if the cathode receives a voltage whose instantaneous value is proportional to the magnitude of the charge stored on the corresponding portion of the target, the complete discharge of the target is effected in one pass of the scanning electron beam. Since the output voltage of a camera preamplifier at any instant is directly related to the magnitude of the charge stored on the corresponding portion of the target of the same tube or a different tube viewing the same scene, the preamplifier output voltage herein is selectively applied to the tube cathode, preferably with an appropriate transfer function, whereby lag in the tube is eliminated.

Abstract: An error detection and correction system locates and corrects double errors in a received data block word digitally encoded in a Reed-Solomon code (n,K) as coefficient terms of an n-order codeword polynomial in the form ##EQU1## where the coefficients are powers of the primitive a of a Galois field, which codeword is divisible by a code generator polynomial in the form of a product of a plurality of different factors in the form (x+a.sup.i). Four syndrome signals are derived, each corresponding to a respective first order syndrome equal to the remainder upon dividing a received data block word by a respective factor. An error locator responsive to the four syndrome signals derives a reference signal corresponding to the position h of a reference term in the received data block word equally spaced relative to the two terms containing errors, and a relative position signal k corresponding to the number of terms by which the terms containing the errors are spaced from the reference term.

Abstract: A phase detection control apparatus is disclosed for detecting any variable where the phase is discretely measured, as for example, in a motor having a tachometer of an optical type. The phase detection apparatus eliminates direction sensitivity and does not suffer from the misposition of any upper and lower limits. The apparatus achieves a phase lock without excessive overshoot and eliminates the possibility of reverse run away under any condition. Moreover, the circuitry is easily implemented with a relatively few number of circuit components and therefore accomplishes the desirable functional capabilities at relatively low cost.

Abstract: A signal comparison circuit is described which is implementable by a logic gate array structure without introducing the possibility of the large, incorrect error signals possible with phase comparators implemented by logic gate array structures. The circuit has particular applicability to phase-locked-loop circuits because it compares the frequency and phase of a first input signal with the frequency and phase of a second input signal in an error-free manner. A first master flip-flop triggered by the first input signal produces negative pulses, under the control of a NAND latch. A second master flip-flop is triggered by the second input signal to produce negative pulses, under control of the same NAND latch. The NAND latch is responsive to the outputs of the first and second master flip-flops. The first and second input signals are each delayed, and the delayed input signals are respectively used to trigger first and second slave flip-flops (which are slaves to the two master flip-flops).

Abstract: A range of digital values is assigned to represent a digitized composite signal, while a selected digital value of the range is assigned as a unique dropout sample to represent only a dropout in the signal to the exclusion of signal data. In the event of a dropout, the unique dropout sample is loaded into memory in place of the corresponding incorrect signal data. The unique dropout sample is detected upon read out of data from memory and used to initiate the process of dropout compensation.

Abstract: A control system for a motor which drives a tape capstan includes a capacitor (91) which holds a sample of a ramp signal which is sampled and restarted in response to tachometer pulses. The output of an amplifier (90, 100) which amplifies the difference between the stored voltage and a reference is integrated by a passive integrator (106, 92) coupled to the capacitor (91). The arrangement provides prediction of change of a discontinuous speed signal and is useful for slow running motors of low inertia.

Abstract: An uncorrected composite color television signal, including frequency-modulated luminance and frequency-transposed chrominance components is recovered from a storage medium and separated by filters into its luminance and chrominance components. The chrominance component is coupled to a frequency converter for converting it back to its nominal frequency, i.e., its frequency prior to the frequency transposition. The frequency and phase of the output provided by the frequency converter is determined by a chrominance subcarrier reference signal provided by a generator. The uncorrected luminance component is employed to adjust the frequency and phase of the signal provided by the generator so that the provided reference signal is coherent with the uncorrected luminance component. This causes the frequency converted chrominance component to be stabilized to the reference signal and to be coherent with the uncorrected luminance component.

Abstract: A tape transport of the U-coiling type having a takeup reel that rewinds in a clockwise direction is provided with a switch reversing this direction to anti-clockwise for rewinding a Z-coiled reel, and the switch is provided with a coordinating portion that clears the tape path only for the coiling direction that corresponds with the switch setting.

Abstract: Plated magnetic recording material, such as magnetic tape, composed of a thin layer of ferromagnetic metal and a base film layer are made by plating a passivated smooth continuous surface such as the surface of a cylindrical mandrel or an endless belt with a plate of ferromagnetic metal, applying the base film layer to the plated surface, and stripping the resulting laminated composite from the surface. The smoothness of the surface of the ferromagnetic metal layer depends on the smoothness of the continuous surface rather than on the smoothness of the surface of the base film stock.

Abstract: In a system for comparing the ratio of two numbers to a threshold, the bits of each number are compared in groups comprising less than the total number of bits. The most significant group of bits are first compared, and if they contain sufficient information to make the comparison, the result thereof is indicated. If the most significant group of bits does not contain sufficient information, the comparison is made based upon the next higher order group of bits that does contain sufficient information. In some situations, it is desirable to obtain information about the next lower order group of bits in order to verify whether a determination is correct. Each of these situations has a unique address in a memory unit dedicated to the next lower order group of bits.

Abstract: An electroless plating bath tank with air sparging and bath heating attachments is provided with a workpiece rack on which multiple horizontal spindles bearing workpieces are rotated about their own axes while also being rotated eccentrically about a horizontal axis, so as to expose the workpiece more uniformly to the action of the bath.

Abstract: A gray scale test chart for television cameras, in the form of either a transmittance chart or reflectance chart, includes one or more regions having selected gray values for calibrating or adjusting the output signal of the television camera, each gray value region being formed by an array of uniformly black dots arranged on a uniformly white background in a spatial frequency selected with respect to the resolution capability of the camera to produce an integrated output signal while being within the resolution capability of a photographic or other chart reproduction technique, the size of the dots in each region determining its gray value in combination with the spatial frequency or center-to-center spacing of the dots.

Abstract: A font recall system stores a font of alpha-numeric characters in a video display format for selective insertion as a caption into a video image. Characters are stored on a video disk in digital pixel form with full dynamic resolution. Low pass filtering is employed to preserve high image quality and eliminate jagged edge aliasing at character boundaries. A first frame store receives selected characters from the video disk through an image size reducer to store the characters at selected display positions with a selected size to form a caption under control of a central processing unit. A keyer receives the caption video data from the first frame store as well as a background image to form a composite image, which is stored in the second frame store before being output as a continuous television video signal.

Abstract: A YIQ computer graphics system includes a data processing system having a data tablet for receiving inputs from an artist and a video processing system connected to the data processing system. The video processing system includes a two component expandable frame store with the first component storing video intensity information for each pixel of a visual image and with the second component storing two video color components each for one-half of the visual image.