Abstract: Dolby AC-3 and MPEG-2 audio permit the transmission of audio signals with more than two independent audio channels. If a reproduction device has only a two-channel audio decoder (DEC1) then an external multi-channel audio decoder (DEC2) can be used for multi-channel sound reproduction. If the audio reproduction at the same time accompanies video reproduction, then a synchronization method is required in order to achieve lip synchronism between picture and sound. According to the invention, for the synchronization of a first decoder (DEC1), which merely has two-channel compatibility, with a second decoder, which has multi-channel compatibility, a counting variable is allocated a value (F) which is produced from system parameters such as the data coding method used, the transmission speed and/or the data rate. The data are received by the first decoder and output by the latter to the second decoder, the counting variable being decremented or incremented respectively for a specific volume of data.

Abstract: A method and device in which only a single symbol is required for synchronization, and which permits the detection of appreciable deviations from the normal receiver oscillator frequency or of a deviation of the transmitter frequency from the given frequency pattern, and the correction of the oscillator frequency. The invention further includes an evaluation method for the signal which contains a multiplicity of modulated carriers. In a decoder, additional sequences are evaluated after demodulation and differential reconversion by means of a correlation.

Abstract: The circuit arrangement comprises at least two movable elements (1 to 3) which are to be monitored and which are assigned a sensor (4 to 6) in each case. The output signals of the sensors (4 to 6) are fed to an evaluation circuit (7) via a common connection. The evaluation circuit (7) has only a single input for receiving the signals of the sensors (4 to 6). Each sensor (4 to 6) emits a pulse shape characterizing the connected element. The pulse shapes of the pulses generated by the sensors are configured in such a way that the evaluation circuit can uniquely identify the individual pulses, even in the case of superimposition.

Abstract: We are familiar with etching printed circuit boards chemically by providing a copper board with a mask and etching copper away chemically at those points where the mask is not present. This is disadvantageous, e.g. from environmental standpoints, because the chemical liquid is increasingly enriched with copper, and, when the liquid has been used, it can no longer be employed and is also difficult to dispose of. The invention is based on the object of providing a method of either applying or removing conductive material electrically.

Abstract: A recording or reproduction device with a three-point scanning arrangement compatible for use with recording media having different track spacings. The invention makes it possible, without changing the setting of the three-point scanning system, to use recording media having different track spacings. According to the invention, the three-point scanning system is set in such a way that the scanning center points have a lateral spacing from one another which is within a range of a first product, formed by a first predetermined value and the first track spacing, and a second product, formed by a second predetermined value and the second track spacing, the range being less than 8 percent of the value of the first product.

Abstract: A device for reading from and/or writing to optical recording media, including a beam generator, a focus device, which focuses the beam generated onto the optical recording medium at a focal point, a displacement device, which displaces the position of the focal point on the recording medium in accordance with a first direction of movement in dependence on an actuating signal, and a detector, which detects a beam reflected from the optical recording medium and outputs a regulating signal to a regulator. The regulator generates an actuating signal for the displacement device. The invention allows a higher data transfer rate to be achieved with an acceptable outlay. This is achieved by a beam influencing device arranged in the beam path and, in dependence on a further actuating signal of the regulator, influences the position of the focal point on the recording medium in accordance with the first direction of movement.

Abstract: The key component of a digital PAL or NTSC color decoder is a quadrature demodulator for these AM modulated signals. For a SECAM color decoder, however, an FM demodulation is required which is conventionally implemented using a Hilbert filter which is followed by a CORDIC processor and a differentiation stage. It would be advantageous if for multi-standard applications a general-purpose color demodulator for PAL, NTSC and SECAM systems could be implemented on one chip having as much as possible common demodulation processing stages. According to the invention a single common quadrature mixer is used for all three color systems. A resulting bias effect caused by the use of a single mixing frequency is corrected in a clamping stage. The bias effect can also be used for line identification.

Abstract: The reduction of interfering influences in an LC resonant circuit with an integrated circuit is effected by including the interfering elements of the housing in the resonant circuit. This precludes the occurrence of parasitic radio-frequency oscillation modes. It also ensures good radio-frequency properties and a wide frequency tuning range.

Abstract: A problem in the reception of terrestrially transmitted digital multicarrier broadcast signals is synchronization in case a receiver is switched on or tuned to another channel. The time required by the receiver to reach a given tuning frequency with adequate accuracy and to determine that the currently received signal is not a system-compliant signal is reduced significantly if a characteristic value calculated from correlation values between a windowed and FFT transformed section of the received signal and a reference symbol stored in the receiver does not exceed a pre-defined threshold. In such case the receiver can go ahead to the next tuning frequency. If, however, the characteristic value exceeds that threshold, then a system-compliant signal is found, even with an offset. The multicarrier signal will be further decoded in the normal way. Such conformity check can also be carried out in the subsequent normal reception mode.

Abstract: In a tape transport for recording and/or reproducing signals by means of a recording medium using separate winding motors for driving the winding plates, the drive of the winding motors servo units is constructed as open-loop control devices and/or closed-loop control devices. Such servo units can advantageously be used for open-loop control and/or closed-loop control of the drive of the winding motor even during a braking operation.

Abstract: Recent circuit concepts inject measurement lines, for cutoff and drive control of the cathode current, into each color channel during the vertical frame blanking period. Owing to the physically dependent exponential beam current characteristic profile as a function of the cathode control voltage VK, the exponent &ggr; of the characteristic profile and the ratio of two cathode components IK1 and IK2 may be used to form control reference values for cutoff and drive control, this process being started in each case from a fixed value of the exponent &ggr; or of the ratio of the two cathode currents IK1 and Ik2. However, it has been found that, if a fixed value is assumed for the exponent &ggr; or for the ratio of the two cathode currents IK1 and IK2, it is not possible to achieve an optimum result for displaying monochrome pictures. Thus, according to the invention, the exponent &ggr; is defined as a function of the color tube 1. The aim in this case is to reduce a &ggr;-dependent DC voltage offset u0f to zero.

Abstract: The invention relates to a method and an arrangement for a compatible recording and/or reproduction device for the reproduction of information from, and/or for recording on, optical information carriers (CD) having differing information storage densities. A light source is used which is adapted to the highest storage density of the information carriers (CD) to be used as regards wavelength and light spot dimensions and the light directed onto the information carrier (CD) is defocused by a defocusing means for the enlargement of the light spot for information carriers (CD) of lower storage density.

Abstract: The bit rate control goals for applications using storage devices with the capability to process a variable bit rate data stream differ from the constant bit rate case. Therefore the encoder control strategy is adapted to this situation. For the first e.g. 80% of the total playing time an average bit rate is produced which is e.g. 95% only of the normal average bit rate. For the remaining 20% of the playing time the value for the desired average bit rate ascends to e.g. 150% of the normal value. During the first 80% the virtual buffer size is increased by a factor of e.g. 100 whereas during the last 20% the virtual buffer size descends to the normal value. Thereby an increased decoding quality can be achieved during e.g. 80% of the playing time. In the remaining playing time there is nearly no loss in the normal decoding quality.

Abstract: Method for the correction of a tracking error signal during optical scanning of a recording medium in the form of a disc. In the case of MO discs, the Kerr rotation angle is in general very small, so that so-called enhancement is used for processing. This leads to birefringence effects which are thermally induced on the WO disc during the writing process producing a noise level on the track error signal. According to the invention, an optical scanner arrangement is used to determine light intensities from two mutually perpendicular polarization planes. A noise element, which is produced by interfering polarization rotation of the light, in the tracking error signal is compensated by linking the electrical output signals of the scanner arrangement. Applicable both to MO and WO as well as CD audio, CD video and CD-ROM.

Abstract: A head drum for a magnetic tape apparatus includes a stationary lower cylinder and a rotating upper cylinder on which at least one write/read head is securely arranged and interacts with a magnetic tape with an exchange of electromagnetic signals. Also provided are at least one amplifier which rotates together with an upper cylinder and amplifies the signals coming from the write/read head, and a rotating transformer for transferring electrical signals between the stationary lower cylinder and the rotating upper cylinder. Storage means for electrical energy arranged on the rotating upper cylinder is capable of supplying electrical power to all the electronic components rotating together with the upper cylinder. A controller is securely arranged on the rotating upper cylinder for monitoring the charge state of the storage means and controlling the duration of the energy transfer as a function of the charge state.

Abstract: A circuit for controlling beam current in a picture tube, which circuit calculates current pictures for the R, G, B beam currents in the picture tube, which largely correspond to real beam currents in the color picture tube. The circuit comprises a comparator/integrator which compares a sum of these current pictures with a beam current information item for the purpose of controlling the R, G, B beam currents and/or the picture sharpness. Gamma correction is carried out in the circuit. The circuit may be of analog or digital construction and may advantageously be integrated in a video processor IC. The present circuit is particularly applicable for television sets or computer monitors.

Abstract: A method is proposed for processing transitional regions in a picture signal. The picture signal comprises a sequence of digital pixel values. A number of adjacent pixel values, which contain a processing pixel value, are combined to form a processing block. A corrected pixel value is calculated for the processing pixel value. The maximum and minimum pixel values are first determined in the processing block to define the transitional region. The transitional region is then split into a number of sections on the basis of the magnitude of pixel value. Finally, a determination is made as to the section in which the processing pixel value is located. The processing pixel value is allocated a corresponding correction value in order to increase, to reduce or to leave unchanged the processing pixel value, in accordance with a predetermined transfer function.

Abstract: A video recorder capstan drive motor is controlled for slow-motion, freeze-frame and similar operations by setting a rate of acceleration or braking. A speed parameter is measured during an initial acceleration phase and is compared to a predetermined desired value. Based on the result of such comparison, current to the drive motor is limited, or an existing current limitation value is increased or reduced, so as to alter the acceleration or braking and bring the tape speed more nearly to the predetermined value. A representative current value can be stored in nonvolatile storage and used for such current limitation control, for so long as conditions remain unchanged. The value can be changed when conditions change, for example due to loading of a different tape cassette or a change in operational temperature.

Abstract: A cache enabling architecture in which an optical storage reading and/or writing device, a caching processor and a mass writing and reading device are each connected to a data bus. The optical storage reading and/or writing device exchanges information directly with the caching processor over the data bus. The caching uses the mass writing and reading device as cache memory.

Abstract: The method according to the invention is distinguished by the fact that a transmitter identifier (SK) is contained in the received channel (EK), the program locations (P) are assigned once to the received channels (EK), and in the event of a deviation from this assignment, the microprocessor (&mgr;P) controls a search (SL) in order that the desired received channel (EK) is assigned anew to the program location (P).