Abstract: An apparatus for electron beam deflection in a cathode ray tube, in particular in a picture tube of a television set, comprises a deflection coil arrangement for horizontal and vertical deflection of the electron beam, an auxiliary deflection coil arrangement, by means of which the electron beam can be influenced for the purpose of convergence correction, and a compensation coil arrangement for producing a magnetic compensation field. The compensation coil arrangement is arranged and designed such that the compensation field essentially compensates for the stray magnetic field of the deflection coil arrangement in the physical region of the auxiliary deflection coil arrangement.

Abstract: It is known in the case of digital helical track recording and replay apparatuses for audio, video and general data to be recorded for pilot tones to be interleaved in the data tracks, for tracking. The interleaving can be carried out simultaneously with the data by frequency decoupling (a) or by superimposition (b). The invention is based on the object of providing a helical track recording and replay system which carries out tracking in a simple manner. According to the invention, the ATF signal is obtained in a filter module, which also carries out the rectification of the filtered-out pilot tones. The two DC voltage levels are interrogated and processed in the servo microcontroller, with A/D converters. Coupled to the rotation of the head drum, pulses are produced by the servo system which switch the ATF conditioning over between direct operation and tracking operation, so that evaluation is achieved by the microcontroller during the fast ATF burst phase.

Abstract: In the case of the OFDM method, a large number of modulated carriers are transmitted using frequency division multiplexing, a spectrum having a virtually rectangular shape being produced as a result of the large number of carriers. In order to separate the carriers from one another again in the receiver, a Fast-Fourier-Transformation is carried out, it then being possible to separate each carrier cleanly from the others provided the carriers are exactly orthogonal with respect to one another. The carrier orthogonality can, however, be disturbed by various causes. Furthermore, the wanted signal must be separated from the undesired adjacent channel signals by analog or digital filtering in the receiver. In order to improve carrier and channel separation, the selectivity of the FFT filtering can be increased by enlarging the number of FFT components. However, this normally leads to an undesirably sharp increase in the computation complexity.

Abstract: A switched mode power supplier having an improved power factor, that is to say a reduced harmonic load on the mains comprising a switch mode power supply with a reduced harmonic load on mains, comprising a mains rectifier being coupled to a charge capacitor and to a series circuit, the series circuit comprising a decoupling element, a primary winding of a transformer, a switching transistor, and an energy storage capacitor coupled in parallel with the primary winding and the switching transistor, with the voltage thereacross being a smoothed DC voltage, the charge capacitor being further coupled to a tap of said primary winding via a second series circuit comprising an inductor and a diode, and the inductor and the diode being connected via a second diode to a point with a fixed voltage.

Abstract: A current supply circuit for an electronic apparatus having standby, normal and economy modes of operation includes a remote control receiver which responds to a remote control signal from a remote control unit to select either mode of operation. A voltage source provides a main voltage which is detected to produce a switching voltage when the main voltage is present. The switching element of a voltage responsive switch is connected to a first input contact in the presence of the switching voltage and to a second input contact in the absence of the switching voltage. The output contact of the voltage responsive switch is connected to an input terminal of the remote control receiver and to a first input terminal of the filter.

Abstract: Tracking error signal in an optical read/write device, such as a CD ROM, are fine tuned for deviations in the positions of the lens structure normal to the recorded medium to provide more precise tracking control. Track error signal is developed by means of DPD-TE circuitry, using for example, signals from a four quadrant photodetector. Selected pairs of the signals from the photodetector are summed and the sums are differenced to develop an intermediate signal. The intermediate signal is amplified with a gain proportional the reciprocal of the intensity of light received by the photodetector, and thereafter combined with the track error signal to provide a corrected track error signal.

Abstract: The coding or decoding of video data with the associated audio and/or other data can be performed, for example, on the basis of the standards ISO/IEC 11172 (MPEG1) or ISO/IEC 13818 (MPEG2). Such coding and decoding can include the conversion of a primary bit stream coded on the basis of such standards into a secondary bit stream with a different data rate. Since the information content of the motion vectors from the primary bit stream retain their validity in the secondary bit stream, it is not necessary to recalculate motion vectors for transcoding. Instead, encoding of the secondary bit stream is performed with the aid of the motion vectors from the primary bit stream which are reused. In such a case, the encoding of the secondary bit stream is carried out in a restricted prediction mode, i.e. only those prediction modes which are described by respective block type or the motion information of the primary bit stream are allowed in the secondary bit stream.

Abstract: A method of controlling track following in a recorder which uses recording in oblique tracks of a magnetic tape without inactive areas between the tracks and wherein data gaps occur in the useful data sequence due to the change of tracks includes the step of filling the time period containing the data gaps with a predetermined sequence of cyclical modifications of code words representing amplitude and degree increments of a symmetrical train of oscillations. A sequence of code words is used to produce incremental portions of the train of symmetrical oscillations whereby a number of incremental portions forms a complete train of symmetrical oscillations. The code words are modified in synchronism with the clock rate at which the useful data of the recorder are clocked.

Abstract: A method is proposed for obtaining signals in electronic devices by means of interpolation between interpolation point values (W0 to W12), the interpolation point values (W0 to W12) being distributed linearly over a region. A number of interpolation values are calculated in each case at a specific interval between the interpolation point values (W0 to W12). The calculation of the interpolation values is then performed as follows: Firstly, a correction step value (a to 1) is determined in each case for an interval bounded by two interpolation point values (W0 to W12) by linear interpolation between these interpolation point values (W0 to W12) . These correction step values (a to 1) are calculated for all intervals. The calculation of the interpolation value in the current interval is then performed such that apart from the correction step value (a to 1) for the current interval use is also made at least of the correction step value (a to 1) of the preceding and/or of the following interval.

Abstract: An apparatus for processing a sequence of control commands for a unit (40) to be controlled is proposed. In this case, the apparatus has first decoding means (22) which are designed to decode a predetermined set of control commands. In this case, this predetermined set of control commands also contains an end command (CMD.sub.-- END), which indicates the end of a control command sequence. In order also to be able to process control command sequences having control commands which are not contained in the predetermined set, the apparatus has further decoding means (23) which are designed in such a way that when an unknown control command (SET.sub.-- BAREA) arrives, they react in the same way as when the end command (CMD.sub.-- END) from the predetermined set of control commands arrives. Undefined states are thereby prevented.

Abstract: The invention concerns a device which comprises a device for displacing to transversely position a multitrack tape in front of a reading and/or writing head. The magnetic tape carries a plurality of elementary tracks which are grouped in several bundles. These bundles are selectively accessed using the device for displacing. The writing and/or reading head can write and/or read information from elementary tracks contained in one bundle at a time. The device for displacing comprise a tape guide acting on longitudinal edges of the tape and transversely translating the tape. Furthermore they comprise either a movable tape reels platform or movable pins to accommodate for the transverse tape displacement.

Abstract: A circuit for controlling the picture tube in a television receiver. In order to generate a high peak white on the screen of the picture tube, it is desirable to drive the output amplifiers at full output. Because of tolerances, for example in the cutoff calibration, the transparency of the picture tube glass, fluctuations in the input signal etc., driving the video output stages to full output may drive the output stages into saturation and disturbances in the form of so-called smears can occur in the picture. The present invention permits the output stages to be driven to full output as far as the highest peak white without the output amplifiers going into saturation and causing disturbances in the form of smears in the picture.

Abstract: A method for digitally transmitting/recording component-coded color television signals includes the step of, upon transition from a first picture aspect ratio to a second picture aspect ratio obtaining at least part of an additionally required transmitting/recording capacity for coding an additionally formed area of pictures with the second picture aspect ratio by vertical sub scanning of one or more chrominance components.

Abstract: Recording or playback devices for optical recording carriers have a servo control circuit which controls the tracking and the focus of an optical scanning unit 1 with reference to an error signal. According to the invention, the error signal is non-linearly amplified upstream of the servo controller, in order to process strong external mechanical effects, normally referred to as shocks, in such a way that the tracking and the focus are retained or adjusted. If there is a defect, such as a scratch on the disc etc., a defect detector and a linear amplifier connected in parallel with the non-linear amplifier are additionally used, the linearly amplified or non-linearly amplified error signal being fed to the servo controller as a function of the output signal of the defect detector. The sign of the error signal, which includes direction information, is retained in the case of the non-linearly amplified error signal.

Abstract: Method and circuit arrangement for commutation of a multiple winding electric motor. Particularly when they are operated with square-wave signals, multiple winding electric motors require effective interference voltage suppression for many applications. The invention specifies a method and a circuit arrangement by means of which trapezoidal waveform control signals are produced upstream of the respective output amplifiers, so that the motor is driven with low impedance, as a result of which there is no need for additional suppression means. The trapezoidal waveform control signals are composed of an operating voltage or a corresponding signal, a reference potential and a triangular waveform ramp voltage, using switching means.

Abstract: The invention relates to a device for positioning a first element relatively to a second element. The device according to the invention uses lifting means comprising a cam element and actuator means to actuate the cam element. The cam element has a plurality of contiguously arranged sectors with machined edges belonging to first and second interleaved groups. The machined edges are shaped such that a response of the lifting means to the actuator means has different values for sectors of said first and second group thereby providing alternately a coarse positioning and a fine positioning. The device may for example be used to position a multitrack magnetic tape and a magnetic writing/reading head relatively to each other.

Abstract: A telecommunications device having a remote controller, which device contains a circuit arrangement for automatic identification of additional information in a program channel by means of which circuit arrangement a transmission of the program channel is classified into a first type for a desired transmission and into a second type for additional information. An additional button on the remote controller gives a user of the remote controller the capability to correct an incorrect classification of the transmission by means of the circuit arrangement. The circuit arrangement can be equipped with automatic-learning logic which, when a button is operated, revises previous decisions relating to the classification and redefines its criteria for the correct changeover time.

Abstract: An arrangement which can produce a stereoscopic image simply and cheaply. An optical unit views an object and a stereoscopic image is provided onto a recording device or a display device by differentially polarizing the beams.

Abstract: Switched-mode power supplies having a switching transistor and a transformer, with whose primary winding the switching transistor is connected in series, usually require a starting circuit, which is connected to an input voltage. Since a current continually flows through the starting circuit even during normal operation, it is endeavoured to keep the said current as small as possible. The switched-mode power supply comprises a threshold value circuit, for example a Zener diode connected in series with a resistor, which keeps the driver circuit turned off after the switching-on of the switched-mode power supply, until the operating voltage for the driver circuit has exceeded a specific threshold value which is referred to one end of a winding on the primary side. As a result of this, it is possible to charge a charging capacitor via the starting circuit with a low current, without currents flowing away.

Abstract: A system for equalizing an input signal including a datastream modulated on a carrier, with respect to both transmission channel distortions and local receiver distortions, includes a network for frequency downshifting the input signal, a controlled non-recursive filter (20) responsive to the downshifted input signal, and a demodulator (30) for receiving an output signal from the controlled filter. A signal processing network, including a filter network with a transfer function (40, 60, 80, 100) which is the inverse of the transfer function of the controlled filter, responds to an output signal from the demodulator for producing output control signals. The control signals are coupled to a coefficient control input of the non-recursive filter for equalizing the signal with respect to both transmission channel and receiver distortion.