Abstract: A tracking filter system including a phase locked loop and a tracking filter is receptive of an input signal of frequency A and undesired frequency X from a signal source such as a frequency modulated/continuous wave radar range measuring system. The phase locked loop circuit receives the input signal and produces a control signal corresponding to a frequency intermediate frequencies A and X. The tracking filter is set by the control signal to pass frequencies above or below the intermediate frequency and thus to pass frequency A and to reject frequency X.

Abstract: A video disc player apparatus having a signal pickup stylus secured to a stylus arm for recovering recorded signal from a disc record, wherein the stylus arm is mechanically biased by a spring force to produce a positive stylus-disc pressure, includes apparatus cooperating with the stylus arm to maintain the stylus-disc pressure generally constant in the presence of stylus-disc displacements normal to the disc surface. A permanent magnet is secured to the stylus arm with its interpolar axis transverse to the stylus arm and substantially parallel to the disc record. First and second coils, coaxially aligned are disposed on either side of the magnet and arranged with their axes parallel to the interpolar axis of the magnet. Energizing currents are applied to the first and second coils creating respective magnetic fields which produce forces repulsive to the pole of the permanent magnet proximate thereto.

Abstract: Markedly increased optical efficiency for a first diffraction order of incident wave energy, such as light, is derived from a layer of transparent material having effectively two serially spaced sinusoidal phase gratings of the same line spacing, each formed as a surface relief pattern thereon, by prescribing the thickness of the layer, the amplitude of the gratings, the respective indices-of-refraction of the layers and of transparent materials bounding the phase grating surfaces thereof, and the angle of incidence of the wave energy.

Abstract: A tri-state logic circuit which, upon failure of its operating potential, produces a high impedance between its output terminals. The tri-state logic circuit includes first and second complementary conductivity type transistors each with a control electrode and with a conduction path. The paths are connected in series to the operating potential. The control electrode of the first transistor is connected to an intermediate point in a series switching circuit the ends of which are connected to the operating potential. The series circuit is responsive to the presence of the operating potential and to binary data and control signal inputs of given values for causing the conduction path of the first transistor to assume a low impedance state. The series circuit also includes on both sides of said intermediate point devices responsive to a loss in the operating potential for causing the first transistor to assume a high impedance state irrespective of the value of the data and control signals.

Abstract: A measuring gauge, suitable for measuring the plastic record caddy for a video disc, uses a transducer and a driver assembly. The transducer includes a plunger which will trigger a detector if a force of less than one gram is applied thereto. The transducer is coupled to the driver assembly. The driver assembly includes a stepping motor for moving the transducer and a target and sensor for providing an indication of a reference position.

Abstract: A power amplifier circuit includes an output complementary emitter-coupled transistor pair driven by a second pair of complementary transistors having a parallel resistor diode combination serially connected between their emitters to establish idling currents. Base drive for the output transistors flows through the resistor of the resistor-diode combination until the potential thereacross exceeds the diode forward breakdown potential after which all increases in drive current pass through the diode. The use of the diode limits the bucking potential in the base current drive circuit thereby enhancing available output power.

Abstract: Milling machine apparatus and method for controlling the relative movement between a working surface and a cutting edge in which said relative movement approximates a mathematically definable path and occurs in a series of line segments each intersecting said path at first and second points with the second point of each line segment being the first point of the next successive line segment. The system comprises first means for determining a maximum distance d' between each successive line segment and said path measured along a line extending from a predetermined reference and passing between said first and second points, where d'=d+.DELTA.d, a predetermined range of value. Also provided are second means responsive to the determination of d' for each successive line segment to then establish the first point of intersection of the next successive line segment, and control means responsive to the determined points of intersection to generate prime moving control signals.

Abstract: A lifting-lowering assembly for a stylus arm employs two flat portions having a pivot axis in the vicinity of the intersection of the two portions, a stylus arm rest on the first portion, and, an upwardly extending member on the second portion. The upwardly extending member cooperates with an electromagnetic device to rotate the assembly about the pivot axis. Air trapped under the first and second flat portions tends to permit gentle lifting and lowering operations by damping the rotational motion of the assembly.

Abstract: A signal to be delayed is applied to a frequency selective path including an inverting active bandpass filter and to a non-frequency selective path including a voltage-to-current converter. The paths are coupled to a signal combiner which produces an output current having a first component proportional to the output current of the converter and a second component directly proportional to the filter output voltage and inversely proportional to the value of a gain control resistor. The resistor is selected to provide a predetermined ratio of the output current components to provide an overall allpass characteristic for the delay circuit and biased to conduct no current under quiescent signal conditions thereby reducing power dissipation. Several circuits may be cascaded for such purposes as peaking and delay equalization in television receivers, video disc players or the like.

Abstract: In a system for recording digital information on a video disc and for playback of the digital information therefrom, the digital data is recorded in synchronism with the color subcarrier signal on a horizontal line adjacent to a constant luminance line. This arrangement facilitates a video disc player having a simple, efficient, video-to-digital interface for separating the prerecorded digital information from the video signal. The player apparatus is responsive to the color subcarrier signal and the chrominance-related output signal of a comb filter, both of which are normally available during video signal processing. Prerecorded digital information representing field number and type of program content is used by a microprocessor controller to provide player features such as locked groove detection, program elapsed time display, and end of program indication.

Abstract: A bistable solid-state device, substantially immune to long term, low level radiation comprises, in combination with memory storage elements, means comprising P-type devices responsive to enabling and disabling signals for conducting signals to and from the memory storage elements only during the presence of read and write signals, and which are substantially immune to the effects of long term, low level radiation, thereby substantially increasing the reliability of solid-state memory cells. Also provided are means for generating a control signal having first and second levels and logic means responsive to said control signals of a first level to generate and supply said enabling signal to said P-type device and further responsive to said control signal of a second level to generate and supply said disabling signal to said P-type device. Sensing means for sensing the state of said bistable memory elements during a time period between successive level changes of said control signals is also provided.

Abstract: A stylus arm assembly is formed by heating the stylus to about 250.degree. F., and then inserting it into a section of heat shrink tubing. The subsequent heating of the joint causes the portions of the heat shrink tubing surrounding the stylus to shrink to fixedly hold the stylus in place.

Abstract: A composite video signal including a timing component and a caption video signal having no timing component are combined to form a resultant video signal for application to a television receiver. The caption signal is produced by a character generator that is normally synchronized with the timing component of the composite video signal. A substitute timing signal is supplied to the character generator and also added to the player output signal under conditions which interrupt the timing component of the composite video signal whereby captions may be continuously displayed on the television receiver notwithstanding partial or total interruption of the composite video signal.

Abstract: An authenticating device comprises a transparent material, such as a plastic, having a thickness no greater than 100 micrometers embossed on one side with a lenticular array of lenslets having focal lengths substantially equal to this thickness, and embossed on the other side with a reflective relief pattern forming a periodic structure periods smaller than 100 micrometers, which periods are of a width that at least approximates that of the lenslets. The reflective relief structure of the authenticating device is secured to a viewable surface of the authenticated item sheet material and each period of the relief structure is comprised of a set of juxtaposed elements having significantly different reflective characteristics from one another.

Abstract: A threshold comparator for use with a dual slope A/D converter has its input potential established at its threshold potential during auto-zeroing. Potential offset means is included in the auto-zero feedback loop around the integrating and output amplifiers of the A/D circuit. Bias current applied to the potential offset means substantially tracks current passed in the comparator so that the potential developed by the potential offset means substantially tracks the threshold potential of the comparator.

Abstract: An FM transmitter linearity test equipment includes an amplitude modulation generator signal source producing an amplitude modulated signal of known varying amplitudes changing at a known rate and a demodulator for demodulating the resulting frequency FM signal from the transmitter. The test equipment also includes a commutating filter operating at said known rate and which is receptive of the demodulated signal for producing a signal of varying amplitude which is compared with the signal produced by the signal source to determine the linearity of the FM transmitter.

Abstract: An adaptive video disc record stylus kicker system for inducing limited stylus translation radially across the disc record. Control circuitry responsive to track identification signals recorded on the disc and to player commands evaluates the error between actual kicker induced stylus translations and the programmed kicker induced stylus translations to calibrate the stylus kicker drive signals.

Abstract: A frequency synthesizer of the phase-locked loop type, having an output circuit circuit which produces an output signal at any of a plurality of alternating frequency values depending on the value of a command signal applied to the output circuit. The synthesizer includes a storage apparatus for storing, for each frequency value, an indication of the precise command signal value which causes the frequency to be produced.

Abstract: An expandable scaler for scaling an N bit digital word. The system comprises first and second scalers each of which comprises N input terminals for receiving an N bit word, N output terminals, and (x+1) corresponding groups of first switching logic to form (x+1) corresponding pairs of groups of first switching logic with each group having input terminals and output terminals and being arranged in successive manner with the output of each of the first (x) groups being connected in parallel manner to the input terminals of the next successive group and where 2.sup.x =N, and leads for supplying the N bit digital input word to the input terminals of the group of first switching logic and further with each pair of corresponding groups of switching logic means responsive to an enabling signal to selectively shift the N bit digital input word by one of 2.sup.o, 2.sup.1,-2.sup.x =m bit positions.

Abstract: A signal source continuously produces a horizontal timing signal proportional to the line rate of a recovered composite video signal. A vertical timing unit coupled to the source continuously produces a vertical timing signal proportional to the field rate of the video signal. An error detector processes data words present in the vertical interval of the composite video signal to provide a data status signal indicative of the validity of each processed data word. The data status signal is applied to the vertical timing unit for synchronizing the vertical timing signal with the vertical synchronizing component of the composite video signal and rendering the vertical timing signal substantially immune to noise which might accompany the composite video signal.