Abstract: An optical position pick-off for proof-mass in a zero-drag satellite is obtained by placing a spherical mass shielded from all forces except gravity, between a flat screen having four equally spaced photodetectors and a light source. The mass interrupts the light beam and casts a circular shadow on the screen, the periphery of which passes through the center of each of the detectors. A shift in the mass in any direction causes its shadow to cover more of certain detectors and less of others or more of all or less of all. The unbalance of the detectors may be used to actuate small jets to change direction of the satellite until the mass returns to its null position.

Abstract: An isolation circuit with duty cycle feedback is disclosed which includes an operational amplifier with capacitive coupled negative feedback such that its output voltage varies to maintain its input terminals at the same potential, and which output is connected to the control terminal of a voltage controlled oscillator which generates a square wave voltage in which the ratio of ON time to the total period is directly related to the voltage from the operational amplifier. The output pulses of the voltage controlled oscillator are fed through a resistor to the negative input terminal of the operational amplifier. The output pulses from the oscillator are also fed through a driver transistor to control the input of an opto-coupler. The output from the opto-coupler passes through an amplifier to produce a square wave voltage with the same ON time ratio as the voltage controlled oscillator.

Abstract: The amplifiers of the present application all include at least two pairs of complementary, metal-oxide-semiconductor (COS/MOS) transistors, each pair quiescently biased to operate as a linear amplifier. An input signal is applied in one phase to the input circuit of one COS/MOS pair and in opposite phase to the input circuit of the other COS/MOS pair. The output signal appears across a load circuit which is connected at one terminal to the joined drain electrodes of one COS/MOS pair and at its other terminal to the joined drain electrodes of the other COS/MOS pair.

Abstract: A coaxial reflex photoelectric scanner comprising first and second lenses, a photoelectric light source and a photodetection device, all mounted within a housing in coaxial relationship with one another. The photodetection device is positioned between the light source and the second lens, wherein the second lens is positioned between the photodetection device and the first lens. The second lens is so positioned that the photodetection device absorbs an optimum quantity of light energy that is reflected back from an object and through the first and second lenses.

Abstract: The improved gain control circuit is comprised of an amplifier, a semiconductor device attenuator at the amplifier input, and unique control circuitry for controlling the attenuation factor of the semiconductor device. The amplifier is designed for low phase shift to minimize the time delay of its transfer function. The control circuitry responds to both positive and negative a.c. signal transitions at the amplifier output to initiate attenuator gain reduction. As with the amplifier, the control circuitry is designed for minimum response time. The combination results in an extremely fast a.g.c. attack time.

Abstract: A molded housing is formed by two opposing mating sections and includes a forward head portion projecting from a handle portion. The housing sections confine therebetween a lens barrel and a light source which have corresponding inclined axes converging toward the bottom surface of a generally V-shaped tip member projecting downwardly from the forward end of the housing. The housing sections also confine therebetween a printed circuit board forming part of an electronic amplifier for a photosensing unit supported within the lens barrel. The lens barrel and light source cooperate with the tip member so that tilting of the housing within limits does not effect accurate reading of a code during scanning. The housing is lined with a layer of metal to shield the amplifier from external electrical interference, and the lens barrel casing may be molded as an integral part of the housing sections.

Abstract: An emitter follower type power amplifier capable of changing over supply voltage and hence the load line, comprising: an amplifying transistor of saturating type; at least a first and a second supply voltage source; a switching transistor having, a collector connected to the first supply voltage source, and an emitter connected to the second supply voltage source via a diode and also to the collector of said power amplifying transistor; a load resistor connected between the emitter of the power amplifying transistor and the ground; and a biasing voltage source connected between the base of the switching transistor and the emitter of the power amplifying transistor. This power amplifier circuit arrangement allows switching-over between load lines for small signal region and large signal region thereby enabling large signal amplification and reducing the collector loss of the power amplifying transistor. This circuit arrangement is also used in a push-pull power amplifying circuit to obtain the same advantage.

Abstract: An optical imaging device divides a long thin object, such as a line of print, into several sections and arranges the sections into an overlapping image, of area form as compared to the original linear form of the object. A plurality of lenses are used, each lens associated with a particular section of the object. Each lens is tilted relative to the other lenses so that the plane of the lens is perpendicular to the line connecting the center of the related image section and object section, and also displaced in a direction normal to the extent of the line of lenses so that the center of each lens is on the line connecting the center of the related image section and object section. The lenses can extend in a curve to reduce magnification variations from lens to lens, and conveniently the lenses are rectangular and molded as a single unit.

Abstract: A radio frequency power amplifier is frequently provided with a feedback circuit to maintain the output power of the amplifier at a predetermined level. When the load connected to the amplifier changes, the feedback circuit causes the amplifier to produce the amount of power needed to maintain the predetermined level of power. If additional power is produced, it may be large enough to damage or destroy the amplifier and other circuits. A protection circuit is provided to prevent this. The protection circuit uses a differential amplifier having a first input provided by an output power sensor, a second input provided by a reference voltage, and an output for controlling the supply power to the radio frequency power amplifier. The two inputs are adjusted so that the differential amplifier becomes saturated when the sensed output radio frequency power is at some selected safe level above the normal output power level.

Abstract: An amplifier circuit suitable for use as a video amplifier in a color television circuit for driving the variable impedance load provided by a color television picture tube, in which the load impedance of the amplifier element of the circuit is also made variable. This is achieved, in one embodiment by using as the output stage of the amplifier two transistors with a complementary symmetrical configuration so that one is always substantially cut-off while the other conducts. In another embodiment a transistor in common collector configuration acts as the amplifier element and its emitter from which the output of the amplifier is taken is connected by a diode to the collector of a transistor which feeds the base of the common collector transistor.

Abstract: A broad-band radio-frequency amplifier is characterized by a gain which may be adjusted over a relatively large range, and which remains stable over the range of gain adjustments. The amplifier includes first and second transistor pairs each arranged in a cascode connection; a feedback capacitor connected across the output and input of each cascode pair; and inductance serially included at selected circuit points. Also disclosed is a hybrid circuit for efficiently implementing the amplifier.

Abstract: An ultraviolet lamp is disclosed wherein the light source is a rapid pulse unconfined xenon arc tube containing more than three atmospheres of xenon gas pressure, and providing an output limited to wavelengths greater than 320 nanometers. Associated circuitry for operating the tube and associated light transmitting means for utilizing the output of the tube are also disclosed.

Abstract: An apparatus for photoelectrically detecting the position of each of the edges of a line having the opposite edges thereof formed substantially parallel to each other on an a substrate thereby to measure the width of the line, comprises a source of coherent light, means for condensing the coherent light into a tiny light spot which illuminates the line, means for imparting to the tiny light spot a minute oscillation having an amplitude less than the width of the line, means for providing relative movement of the tiny light spot and the line so that diffracted light may be created at each of the edges of the line, a first photoelectric conversion element for receiving chiefly the diffracted light created at one of the edges of the line, a second photoelectric conversion element for receiving chiefly the diffracted light created at the other edge of the line, and a circuit for producing position signals corresponding to the edges of the line from the output signals from the first and second photoelectric conver

Abstract: An automatic gain control amplifier having a controlled recovery of gain is disclosed and includes a peak detector for generating an output when the amplifier output exceeds a predetermined level, a memory setting circuit responsive to the peak detector output, a memory controlled by the memory setting circuit, and a memory adjust circuit responsive to information derived from the amplifier output. The output of the memory controls an attenuator of the automatic gain control amplifier. Amplifier output level change detection circuitry is also disclosed and accepts the output of the amplifier for producing an output indicating amplifier output level changes exceeding a predetermined magnitude. The level change detection output controls the memory adjust circuit.

Abstract: For the lateral guidance of travelling webs, three photoelectric detectors are arranged under one margin of the web in a transverse line such that the path of light from a light source, on the other side of the web plane, to a first of the detectors is blocked by the web, the light path to a second of the detectors is partially blocked by the web, and the third detector is fully exposed to the light source, when the web is in its normal lateral position. Signals from the three detectors are combined in such a manner that a signal is derived representing the extent to which the second detector is covered by the web, the value obtained being corrected for variations in light source intensity and for web translucence.

Abstract: The invention relates to a system for detecting the height fluctuations of a surface on a recording medium in an optical recording or reproducing apparatus. A light source emits a main light beam for recording or reproducing. An optical system, including an objective lens, focuses the main light beam into a spot on the surface. A first reflecting mirror introduces a sublight beam into the peripheral part of the main light beam. The sub-light beam advances in a forward path through the objective lens to be projected onto the recording surface and reflected thereby. The sub-beam returns again through the objective lens along the peripheral part of the main light beam, but on the opposite side from said forward path.

Abstract: The method consists in generating an electrical signal B which is representative of the time-dependent variations in transparency, in generating a pulse at the initial instant of measurement, in carrying out an initial measurement of the slope of the curve at the beginning of the portion which has a steep slope, in comparing at predetermined instants the measured value of the initial slope with the slope of the curve which is representative of the signal B at these instants, in generating a second pulse when the measured slope becomes significantly different from the initial slope, and in measuring the time interval which elapses between the first and second pulses.

Abstract: A pressure actuated light pen attached to the end of an optical fibre bundle has a retractable tip in which is formed an aperture. No image is focussed onto the ends of the fibres until the tip, with the aperture, is retracted to a predetermined position. At this position, the aperture is effectively focussed onto the ends of the fibres, to give an image of sufficient brightness for detection, and processing, by associated circuitry.

Abstract: A circuit for adjusting the amplitude of a reference signal to a predetermined level so as to permit subsequent data signals to be interpreted correctly. The circuit includes an operational amplifier having a feedback circuit connected between an output terminal and an input terminal; a bank of relays operably connected to a plurality of resistors; and a comparator comparing an output voltage of the amplifier with a reference voltage and generating a compared signal responsive thereto. Means is provided for selectively energizing the relays according to the compared signal from the comparator until the output signal from the amplifier equals to the reference signal. A second comparator is provided for comparing the output of the amplifier with a second voltage source so as to illuminate a lamp when the output signal from the amplifier exceeds the second voltage.

Abstract: A feedback resistor is interposed between a reversing input terminal of an audio amplifier and at least one impedance circuit. The impedance circuit is connected to an output terminal of the amplifier to receive an amplified audio signal from the amplifier. The signal controlled in its frequency characteristic in the impedance circuit. A fraction of the signal is negatively fed back to the amplifier through a feedback resistor.