Abstract: A method of structuring vectorized data obtained by scanning a drawing or other document comprising the steps of displaying on a computer controlled display screen a template image comprising template lines and nodes corresponding to the acquired image data and selecting portions of the acquired image data to be designated for inclusion in a restructured image data set by using a screen cursor to select the corresponding template lines displayed on the screen. Inclusion designations are subsequently and selectively removed as desired from portions of the acquired image data from the structured data set by using the cursor to select the corresponding lines and nodes on the screen. When the desired portions of the acquired data set are selectively designated for inclusion in the restructured data set, all remaining designated data is copied into the restructured image data.

Abstract: A dead zone in the transfer function of a signal processing system, such as a VTR, is detected by impressing on the system a test signal that is formed within a predetermined interval from a sinusoidal waveform modulated by an envelope function that reduces to zero at a predetermined time. The existence of the dead zone is detected by observing whether the corresponding output signal of the signal processing system has a constant amplitude at times other than the time at which the envelope function is zero.

Abstract: A microprocessor-based apparatus for testing the electrical condition of electronic circuitry, particularly computers, employs a buffer and a latch associated with each of the address bus and the data bus to provide electrical isolation of said buses. In using the apparatus, the integrity of a central testing "kernel" comprising the testing program itself with its testing data in ROM is first verified. The testing program then evaluates, in order, the data bus, the address bus, and then such additional and addressable circuitry as may be connected to said data bus and address bus. Incorporation of analog-to-digital converters permits determination of actual circuit node voltages, in addition to digital levels or the presence of open or short circuits.

Abstract: A post-deflection accelerating and scan expansion lens system (10) is disclosed which may be used in a cathde ray tube (12). The lens system comprises an accelerating and scan expansion lens (70) of the quadrupole type including a pair of coaxial cylindrical electrodes (72, 74) and first and second compensating lenses (66, 78) on opposite ends thereof to provide a bright image of the desired size in sharp focus and great detail on a fluorescent screen in such tube. The first compensating lens (66) is supported adjacent the input of the accelerating and scan expansion lens to provide a linear magnification of the amount of electron beam deflection produced by the vertical and horizontal deflection plates (46, 48 and 50, 52).

Abstract: A Schottky barrier diode is made from a substrate of semiconductor material by forming, on a major surface of the wafer, a layer of dielectric material defining a restricted opening through which the semiconductor material is exposed. A metal which forms with the semiconductor material a single phase compound which is inherently stable at temperatures up to 600 deg. C. is deposited into the opening, into contact with the exposed semiconductor material. By heating the substrate and the metal deposited thereon, the metal reacts with the semiconductor material to form a body of the single phase compound. A layer of refractory metal which reacts with the dielectric material is deposited over the dielectric material and the body of single phase compound.

Abstract: An electromagnetic deflection circuit is disclosed. The deflection circuit includes a plurality of loss elements. These loss elements are responsible for the production of an inherent time delay between the energization of the circuit by an input signal and the generation of a magnetic flux used to deflect an electron beam within a cathode-ray tube. According to an exemplified embodiment of the invention, a DC level shift signal generator, a beam position input signal generator, and an adder for adding the DC level shift signal to the beam position input signal produce an input signal that energizes the correction deflection circuit. The introduction of the DC level to the beam position input signal effectively advances, in time, the output signal from the convergence correction signal generator. This advance compensates for the various time delays present in the deflection circuit.

Abstract: A data storage element having input and output ports isolated from a regenerative latch portion so that the data transmission path is not through the latch. The circuit arrangement provided greatly reduces the probability of a metastable occurrence and permits data acquisition at a high rate with minimal error, and thus is suitable for use in high-speed digital shift registers.

Abstract: A digital storage oscilloscope is provided with an anti-aliasing filter circuit utilizing a first plurality of switchable analog filters that bandwidth limit frequencies greater than half the oscilloscope's sampling frequency, and a digital transversal filter effective at lower sweep rates and sampling rates for also bandwidth limiting frequencies greater than half the sampling frequency. The digital transversal filter is controllable to provide a different band pass characteristic for different sweep and sample rates. Both the selection of filters and the control of the digital filter are responsive to the oscilloscope's selection of sweep rate.

Abstract: First and second transistors are connected as a differential pair, and a third, current source transistor has its collector connected to the emitters of the first and second transistors and draws a first constant current. Fourth and fifth transistors are connected as a second differential pair with the collectors of the fourth and fifth transistors connected to the collectors of the first and second transistors respectively and with the bases of the fourth and fifth transistors connected to the bases of the second and first transistors respectively. A sixth, current source transistor has its collector connected to the emitters of the fourth and fifth transistors and draws a second constant current that is much smaller than the first constant current. All four transistors of the two differential pairs are essentially identical, and the two current source transistors have the same parasitic capacitances.

Abstract: A CRT calibration system is provided having a CRT with a display screen, an electron gun system, and a plurality of feedback elements. Each feedback element has an active area disposed proximately to the display screen at a preselected location such that an electron beam from the electron gun system can strike at least a portion of the active area. In response to being struck by electrons, each feedback element provides a feedback signal related to the area of the portion struck. The system also includes a detector system for detecting each feedback signal, and an integrating analog-to-analog converter which, in response, provides a digital signal related to the portion of the active area struck and thereby to the position of the electron beam relative to the particular feedback element interrogated.

Abstract: Timing pulses are generated in response to an input signal which includes a train of nominally periodic pulses by determining whether a detected pulse of the input signal is a pulse of the train of nominally periodic pulses, employing a detected pulse of the pulse train to initiate cyclical production of pulses with a period dependent on the nominal period of the pulse train, and using the cyclically produced pulses to generate the desired timing pulses. In a gen-lock circuit, this arrangement facilitates acquiring lock to a noisy signal.

Abstract: An air assisted drop-on-demand ink jet head 10 has an ink chamber with an ink drop-forming orifice outlet 23 from which ink drops are generated in response to pressure waves caused by a piezoelectric crystal 56. The ink drops are carried by air outwardly through an external orifice 24 and toward printing medium. The internal orifice outlet 23 is centered in a projecting structure 48 which extends toward the external orifice 24. In one form, the projection 48 is of a frustoconical or mesa-like shape. Air flowing past the top of the projection prevents ink from wetting anything but the top of the projection, resulting in highly uniform ink drop formation with a single uniform dot being produced on the printing medium in response to each pressure wave.

Abstract: An electrical circuit is described that requires a reduced number of data bits for character-address and video-mode information by using a predetermined bit combination of the video-mode information as part of the character-address information. Character-address and video-mode information is output from a random access memory (RAM) to a character read only memory (ROM) and a video-mode detection circuit that produces outputs to enable video-mode circuits in the video control circuitry. One output of the video-mode detection circuit is coupled to an address input of the character ROM that has characters divided into two character sets. A predetermined bit combination of the video-mode information produces an output from the video-mode detection circuit that selects one of the character sets while the other bit combinations produce an output from the detection circuit that selects the other character set.

Abstract: A self-calibrating time interval meter including means for measuring time intervals using a dual-speed ramp technique. The time interval meter operates in a measurement mode to measure time intervals and operates in a calibration mode for calibration adjustments. In measurement mode, the time interval meter utilizes a dual-speed ramp technique to expand the time interval to be measured. A capacitor is rapidly charged by a first constant current source during the time interval to be measured, and is then slowly discharged by a second constant current source. The time required to discharge the capacitor is measured and utilized to compute a measurement of the time interval. In calibration mode, a flip-flop is alternately switched into and out of the circuit to provide two time interval measurements that differ by exactly one clock period of a known clock signal. A microprocessor subtracts the two measurements and compares the difference to the known clock period to determine a calibration error.

Abstract: A frequency domain characteristic of a system under test (SUT) is measured by using a digital signal corresponding to a swept frequency analog signal. In the case of a digital SUT, the digital signal is applied to the SUT, the output signal from the SUT is converted to analog form, and a measure of the peak-to-peak amplitude of the analog signal is derived. In the case of an analog SUT, the analog signal is converted to digital form, the analog signal is applied to the SUT, and a measure of the peak-to-peak amplitude of the output signal from the SUT is derived.

Abstract: A binary ripple counter having exclusive OR coupling elements between the counter bistables for use in a digital delay by events circuit of a display device such as an oscilloscope. The counter is programmable.

Abstract: An enchanced luminance field sequential color image display system having an image source for providing a sequence of monochrome images. The monochromatic light images are formed of first, second and third different spectral colors. A liquid crystal switching system having crossed color selective polarizers is used to transmit the second and third colors with a first direction of polarization and to transmit the first and third colors with an orthogonal direction of polarization. A liquid crystal retarder is used to rotate the direction of polarization of light incident from the crossed polarizers by ninety degrees when the retarder is in its OFF state and to transmit the light substantially unchanged when the retarder is in its ON state. The light is then coupled to an analyzing system which in one embodiment is a neutral polarizer that transmits either the second and third colors or the first and third colors, depending on the state of the liquid crystal retarder.

Abstract: A stand for a computer display terminal is described which enables the terminal to be tilted in a vertical direction, swiveled in a horizontal plane and adjusted in height. The height adjustment is accomplished by a pair of telescoping posts attached between a swivel base member and tilt carriage arms on opposite sides of the computer terminal. A gas cylinder is provided to counterbalance the weight of the terminal and is connected to the telescoping posts by flexible connectors, such as metal cables. As a result, the user adjusts the height by merely overcoming the friction of the telescoping posts the pulley system and the gas spring since the weight of the computer terminal is counterbalanced by the gas cylinder. A releasable brake is provided on the base member which also includes a glide means for enabling gliding movement of the stand over a support surface only when the brake means is released.

Abstract: A surface mount package for toroids or the like inductive elements has the element sandwiched between two non-conductive plates. Spring clips hold the sandwich together, and the element leads are connected to the clips. The assembly is potted, leaving only one end of the clips exposed for surface mounting on a circuit board.

Abstract: A switching power supply that comprises a base drive transformer, a switch device connected to one end of the transformer's primary winding, and a transistor having its base connected to one end of the secondary winding and its emitter connected to the other end of the secondary winding, also comprises a current-dependent voltage clamp connected across one winding of the transformer. The clamp circuit prevents the voltage across the primary winding from exceeding a predetermined value so long as the magnetizing current that flows in the primary winding when the switch device is opened does not exceed a predetermined value.