Abstract: In a linear tracking pickup arm type automatic record player, the position of the pickup arm is opto-electrically detected by the use of a multi-window scale and a photo-coupler unit, and the pre-assigned position signals stored in a memory are compared with the detected position signal to control the movement of the pickup arm. Therefore, the reproduction and the precisely repeated reproduction of any part of a record disk are made possible.

Abstract: A low inductance resistor comprising a metalized, planar silicon wafer, positioned beneath the emitter tabs of an RF power transistor to provide dc balancing and stabilization and thus eliminate the need for more costly collector feedback circuits.

Abstract: A sound motion picture camera with sound recording equipment rendering it possible to record sound accompaniments by way of a magnetic track on the picture film and provided with an automatic gain control circuit operating with attack and recovery times automatically controlled in accordance with variation of the dynamic range of the sound accompaniment.

Abstract: An imaging detector system for improving the lock-on stability of an optical system and in particular a multi-dither coat system. A quadrant non-coherent detector is disposed beneath a variable stop iris for receiving focused light from a target. The quadrant detector generates a signal in each quadrant sensor region which has a value proportional to the intensity of the light impinging on that sensor region. The signals so generated are processed in a signal processor to generate x-y steering command signals which drive a motor which in turn drives a slewing mirror so that the area of the quadrant detector upon which the greatest light intensity occurs is centered relative to the iris aperture when viewed in the direction of the return optical energy. When the high-intensity region is centered, the aperture of the variable stop iris is decreased to prevent the problem of glint jump.

Abstract: A curve-following device having an optical sensing head which senses a guide zone containing the guide line to be followed and having at least a substantial transverse component, and which is movable along the guide zone at a substantially slower speed than the sensing rate and is connected to a control instrument which forms, from the signals delivered by the sensing head, control signals for the movement of the sensing head along the guide line. Marks associated with the guide line and detectable by the sensing head are detected for tripping further control commmands. At least one separate code zone which is sensed separately from the guide zone is provided at the side of the guide zone.

Abstract: An amplifier comprised of a field effect transistor whose gate electrode is adapted to receive an input signal. An impedance converter couples the input signal to the gate electrode of the field effect transistor, the impedance converter being formed of n impedance converting stages, each stage having a relatively low output impedance. A voltage limiting circuit is connected between the source of input signal and the gate electrode of the field effect transistor so as to limit the forward biasing of the field effect transistor. This voltage limiting circuit includes m voltage-limiting elements, wherein n and m are integers (1, 2, 3, . . . ) and n is equal to or greater than m. In a preferred embodiment, the amplifier is formed of two field effect transistors connected in push-pull relation, each field effect transistor being provided with an impedance converter and a voltage-limiting circuit as described above.

Abstract: An automatic ambient light compensating circuit for use in conjunction with a light sensing device to render the light sensing device insensitive to variations in ambient light conditions and which is particularly adapted for use with reflective sensor systems. An optical sensor, including a source of light and a first photodetector, is disposed to detect the presence of an object in proximity thereto. The optical sensor provides an output signal which is a function of the amount of light received by the first photodetector and includes light from the source of light and ambient light. The output signal of the optical sensor is provided as an input to a signal level detection means. A second photodetector responsive only to ambient light is operatively connected in parallel with the output of the optical sensor to the level detection means to compensate the output signal of the optical sensor for ambient light conditions.

Abstract: A high-speed voltage subtractor circuit suitable for use in a serial-parallel A/D converter uses differential current switches to select a predetermined reference voltage value as one input to a precision current matching circuit whose other input is an applied analog input signal. An output buffer circuit coupled to the current matching circuit produces an output signal equal to the difference between the analog input signal and the reference voltage value.

Abstract: Operational amplifier circuitry is provided which comprises an operational amplifier having a first input port and a second input port, and a compensating circuit for making a voltage difference between the first and the second input ports of the operational amplifier substantially equal to the offset voltage of the amplifier, compensating the bias currents of the operational amplifier. The compensating circuit may include a series of a first resistor and a second resistor connected between the first and the second input ports of the amplifier. The node connecting the first and the second resistors is coupled to a predetermined voltage, the resistances of the first and the second resistors being selected so that a voltage difference between the first and the second input ports of the amplifier is substantially equal to the offset voltage of the operational amplifier.

Abstract: An amplifier circuit is provided with a first transistor receiving at the base an input signal and a second transistor related to its first transistor in complementary fashion. A first load resistor is provided between the base and the collector of the second transistor. A second load resistor is provided between the junction of the collector of the first transistor and the emitter of the second transistor and a power source. An output signal is taken out from the junction.

Abstract: An apparatus is described for reading a record carrier with an optical information structure, in which apparatus errors in the focussing of a read beam on the information plane are detected with an astigmatic focussing-error detection system.By including a beam splitter in the path of a beam which has been reflected by the record carrier and by including an astigmatic focussing-error detection system in each of the paths of the two sub-beams thus obtained, the astigmatism of the one detection system being opposed to that of the other detection system, a focussing-error signal can be derived which is independent of optical faults in the read apparatus.

Abstract: A common emitter amplifier having a resistor in series with its emitter and a resistor in series with its collector is temperature stabilized by providing a current source in parallel with the resistor in series with the collector. The current source provides additional emitter current to the transistor to decrease the transistors internal AC emitter resistance. Cascoded transistors are also used to improve the performance of the amplifier.

Abstract: A buffer amplifier suitable for being driven by a differential amplifier having a differential-to-single ended converter is disclosed. The buffer amplifier includes a multi-collector input transistor of a first conductivity type and an emitter-follower output transistor of a second conductivity type. The base of the output transistor is connected to a first collector of the input transistor. A bias circuit for the output transistor is connected to the first collector of the input transistor and to the base of the output transistor. A negative feedback network is connected between the emitter of the output transistor and the base and second collector of the input transistor to stabilize the quiescent output voltage. Current sources are utilized for maximizing the amplitude of the dynamic output voltage and for facilitating temperature independence.

Abstract: A line scanning apparatus employing a multiplicity of linear arrays, the linear extent of which is less than the length of the scan line. To permit an entire line to be covered, the arrays are offset from one another in the direction of scan with adjoining array ends overlapped. To correct for the misalignment and redundancy introduced, the image data from the arrays is buffered until a line is completed when readout, is initiated. During readout, cross over from one array to the next is effected within the overlapped areas and the redundant data discarded.

Abstract: Illumination control apparatus for supplementing light from solar radiation with light from an artificial light source to compensate for periods of insufficient levels of solar light to maintain a desired illumination level within an interior space comprising an artificial light source connected to an electrical power source with switch means for selectively energizing said light source, actuator means for controlling the on-off operation of the switch means, a light sensor connected to the actuator means for controlling the actuator means in response to the illumination level of the interior space, and a limit switch carried adjacent the actuator for limiting the movement of the actuator within a predetermined range so as to prevent further movement thereof during detection of erroneous illumination conditions.

Abstract: An active filter, capable of being electronically controlled over a 50:1 or greater frequency range, while maintaining a fixed filter characteristic and a constant, nearzero DC offset voltage. The filter utilizes passive element-multipliers, either capacitor-multiplier or resistor-multiplier circuits, as the frequency determining networks, depending upon whether the filter is a low-pass or a high-pass filter. Tuning is accomplished by varying the gain of a variable gain amplifier connected in series with the capacitive or resistive element of the multiplier networks. Also disclosed is an implementation of the variable gain amplifier which permits the filter's cut-off frequency to be controlled digitally. The filter may be designed to have any desired type of filter characteristic. Several filter sections may be connected in cascade to provide any desired number of filter poles.

Abstract: An amplifier device comprises a pair of cascode connected transistors wherein the base of the first transistor is connected to an input terminal, the emitter is grounded through a resistor, the collector is connected to the emitter of the second transistor, the collector of the second transistor is connected to a source through a resistor and to an output terminal, and the base of the second transistor is connected to the emitter of the first transistor via a biasing circuitry. The voltage drop between the collector and the emitter of the first transistor is kept constant irrespective of the input signal voltage. The amplifier operates stably with a small deformation of the waveform.

Abstract: Amplifier device for the UHF-TV band, assembled from cylindrical conductors which are coaxially arranged with respect to one another and connected to a tetrode. The screen grid is grounded and the control grid is provided with dc voltage connecting terminals required for setting the tetrode.

Abstract: A circuit useful in replicating the current produced in a photo diode operated as a current source at zero bias. A second scaled area photo diode is used to bias the circuit to maintain the zero bias over a wide range of illumination levels. The circuit operates in the picoampere range and is linear over at least six orders of magnitude.

Abstract: A cone optical system comprising:(a) a convex conical mirror having a symmetry axis,(b) a refracting element having at least one conical surface, with a common symmetry axis with said convex conical mirror, said mirror and refracting element having apex angles selected such that a first paraxial light beam impinging said convex mirror in a direction substantially perpendicular to said symmetry axis is reflected toward said refracting element, traverses same and emerges therefrom as a second paraxial light beam, and(c) a collecting lens on the side of said refracting element opposite said mirror and adapted to focus said second light beam onto an image point located on said symmetry axis.