Abstract: A system for compensating misalignment between information represented by transitions in a data bearing medium and a played back signal, the played back signal having consecutive opposite-polarity peaks corresponding to said data transitions, which system comprises a low-pass filter, which receives a signal from a non-linear element, preferably a pulse forming circuit, into which has been introduced the misaligned played back signal, and circuitry for converting the filtered signal to a series of pulses representative of the data transitions, which pulses have reduced misalignment with respect to the data transitions.

Abstract: A tapped delay line (38) terminated with its characteristic impedance at both ends is connected to receive a differential input signal in intermediate taps (27, 29) of a delay line. Delay line taps (25, 27, 29, 31), as well as ends (21, 23) are connected symmetrically to two pair of summing networks (59, 61 and 83, 85) where voltage signal components having different delays from the input signal are linearly combined. One pair of summing networks (59, 61) produces a balanced differential output signal which is an amplitude equalized and differentiated version of the input signal, while the other pair of summing networks (83, 85) produces another balanced differential output signal which is a different amplitude equalized version of the input signal. Each version is needed in one of the channels of a dual channel signal detector for detecting the peaks of the variable amplitude input signal.

Abstract: A logic clock signal generator implemented with delay lines having a plurality of taps, wherein the taps are selectively feedback coupled to the input to produce a clock signal having a plurality of selectively variable time periods.

Abstract: A crossed light beam position indicator includes orthogonal arrays of paired light emitters and detectors for covering a display surface with crossed light beams and scanning means coupled to the emitters and detectors for electronically scanning the orthogonal arrays such that a single emitter at any one time is emitting light. Improved initialization means detect the first occurrence of an interrupted light beam and in response to the first detection, reset the scanning means to the initial reset position to thus avoid transmitting an address that might represent only the edge of an object placed in proximity to the display screen and caught by the scan only after the scan had passed the position occupied by the main body of the object.

Abstract: A rework layer for a multi-layer printed circuit board comprised of a reference layer and a wire network containing a plurality of conductors tailored to match the impedance characteristics existing between the internal layers of the printed circuit board, wherein the conductors can be selectively terminated after fabrication of the printed circuit board.

Abstract: A circuit for controlling the charge and the voltage of a substrate for use with integrated circuit devices.

Abstract: The present invention comprises a low gain amplification circuit for amplifying the output of a light detecting transistor and producing a logic outputstrong enough to drive standard transistor logic circuitry. One or more bipolar non-symmetrical transistors are arranged in a cascade connected circuit to produce an amplification gain less than that of a single conventional transistor. The bipolar non-symmetrical transistors are reverse connected between the high level and low levels of the power supply and all feedback lines are eliminated while the frequency response is substantially increased.

Abstract: An AC to DC power supply having a multi-channel, flyback inverter output section regulated via a fixed frequency, pulse width modulation controller. The controller indirectly regulates each channel by regulating an auxiliary channel, whereby the duty cycle of a switching transistor in the flyback inverter section is varied to maintain a constant DC voltage on the auxiliary channel and correspondingly on each output channel.

Abstract: A graphic forms overlay apparatus to be used with non-impact printers requiring the use of a movable light sensitive medium such as laser printers is disclosed. Laser printers use a sweeping laser beam and a movable light sensitive medium to image data from a data processing source for printing. A graphic forms pattern is overlayed on the data imaged on the light sensitive medium for simultaneous printing of the data and pattern. To accomplish this a negative of the pattern is mounted on a hollow rotatable forms drum, and inside the drum a fluorescent tube is fixedly mounted for illuminating the negative. A linear portion of the light image of the negative formed thereby is reflected by an optical system of lenses and mirrors onto adjacent linear portions of the light sensitive medium being swept by the laser beam for imaging of data.

Abstract: The output signal of a voltage-controlled oscillator of a phase-locked loop has its phase compared with the phase of incoming data in a phase detector producing a first signal. This first signal is then passed through a non-inverting amplifier to produce an amplified signal of the same polarity. The first signal is also passed through an inverting amplifier otherwise similar to the non-inverting amplifier to produce an amplified signal of opposite polarity. The inverted and non-inverted amplified signals are then filtered in respective low pass filter circuits and combined differentially in an amplifier which produces an error voltage for the voltage-controlled oscillator. Differential combining of the inverted and non-inverted amplified signals eliminates undesired D.C. voltage components caused by temperature drifts and the like by mutually cancelling such components while effectively doubling the amplitude of the desired error voltage.

Abstract: A crossed light beam position indicator includes orthogonal arrays of paired light emitters and detectors for covering a display surface with crossed light beams, scanning means coupled to the emitters and detectors for electronically scanning the orthogonal arrays such that a single emitter at any one time is emitting light. Improved scanning means include means for scanning the detector associated with a particular emitter and in addition scanning one or more adjacent detectors during the time that a single emitter is activated to provide plural light paths from a single emitter and thus more precisely define the position of an object placed in proximity to the display surface.

Abstract: An improved shielded ribbon cable arranged to expedite termination of the shield for grounding the shield. There is an isolator strip placed during fabrication of the cable between the conductor array and the shield; the isolator strip prevents flow of plasticized insulating material between the cover sheet and the conductor array, which usually occurs through the interstices in the shield, so that the shield can be readily separated from the conductor array to permit termination of the shield without jeopardizing the integrity of the insulation on the conductor array.

Abstract: A power driver control circuit (38) provides control signals (44, 46, 48, 50, 52, 54) for switching transistors in a power driver (56) for an electromagnetic actuator (11) of the type used for controlling a servo head (12) in a closed loop servo system. The control circuit includes variable time delay circuits (70, 71) connected to threshold detectors (74, 84) so that dead zones can be created when the servo error signal changes polarity thereby isolating the switches and preventing switch burn-out.

Abstract: A mixtureand method are disclosed for growing bismuth lutetium iron garnet crystals via liquid phase epitaxy on a gadolinium gallium garnet (GGG) substrate wherein the crystals exhibit a relatively high Faraday rotation and an improved optical absorption.

Abstract: The present invention switch comprises a pair of electrodes separated by resilient resistive material which changes resistance several orders of magnitude in response to light pressure. Sensing and amplifying means are provided to detect a predetermined change in resistance. An array of a plurality of such switches may be arranged in a switching matrix to provide any desired form of switch controls or a keyboard for numerous electronic applications.

Abstract: A light emitting source and a light sensing device are permanently fixed on one side of a moving object substantially separated one from the other. The light rays from the source are bent or reflected in a predetermined path so that the light rays to be sensed passes through at least two holes in said moving object before being sensed, thus enhancing the light to dark ratio and reducing the probability of false readings.

Abstract: The present invention comprises selectively locating electrical shorting rings on the male section of an optical cable connector. The particular locations of the rings chosen is commensurate with the length of the cable and provides a basis for amplifying the signals being transmitted along the optical cable. On the female section of the cable connector there are electrical contact devices which can be shorted by the rings on the male section if such rings are present. There is a selectable amplifier circuit connected to the optical cable and the contact devices, and depending upon which contact devices are shorted the amplifier circuit provides the proper amplification to the optical signals which are being converted into electrical signals.

Abstract: There is described a map memory system with a time-multiplexed memory address bus wherein the mapping function is performed on the high order address bits in parallel with the output of the low order address bits on the time multiplex bus.

Abstract: A memory system which already includes an address register, a randomly accessible memory unit, a data-in register and a data-out register is converted to also include a one word buffer memory with the addition of only a few components. A plus one adder is included for incrementing the address contained in the address register and the result is then stored in an address plus one register. The randomly accessible memory unit may be accessed with the address plus one register when it has completed the normal access with the address register pending a new request. The resultant memory data from this access at the incremented address is stored in a one word internal register which is a buffer to the randomly accessible memory unit. Since such access is noninterfering with and overlapped in time with the overall memory system communication with a requestor, and pending any new request to the randomly accessible memory stores, it serves to efficiently create a buffer store only for the next consecutive address.

Abstract: The present invention provides a means for readily monitoring the optical densities of colors which make up a display or particular arrangement (such as pictures in a magazine which are printed with colored inks), and includes means for automatically detecting which of the basic colors predominant in a color is being monitored. In addition the present invention includes means to indicate to the user that the optical density of a predominant basic color detected is satisfactory with respect to, or different from, a desired reference value and provides information to enable the user to correct the optical densities of the basic colors being used prior to creating future displays, for instance the system provides information to enable the user to readily adjust the ink flow in a printing press during a printing "run.