Abstract: A method for convergence correction in a television receiver and to a television receiver, in particular a projection television receiver having in each case one monochromatic picture tube for the three primary colours, red, green and blue, improves the quality of convergence correction. Each picture tube is assigned a correction device which comprises a convergence circuit. The convergence circuit is assigned a memory in which correction values for the convergence correction of the three picture tubes are stored. In accordance with the correction values, the convergence circuit generates output signals, which are output to a correction device, which in each case comprise at least one correction coil and, for each correction coil, one driver circuit. A correction current is applied to the associated correction coil in order to correct image defects of a picture tube.

Abstract: A method for coding digitized frames of a stroboscope-like special effects film is proposed, in which alternately a first number of frames of a first film scene and a second number of frames of a second film scene is shown. Two frame buffers (30, 32) are available for coding the frames. The method is characterized by the fact that the two frame buffers (30, 32) are operated separately so that in each case one of the frame buffers (30) is permanently used for predicting frames of the first film scene and the other frame buffer (32) is permanently used for predicting frames of the second film scene. In addition, a corresponding method for decoding frames coded in this manner and devices for coding and decoding digitized frames of a stroboscope-like special effects film are also proposed.

Abstract: A method and apparatus for dynamic contrast improvement in video pictures. There is a strong demand for picture contrast but each video display has a limited dynamic range. The picture contrast can't be increased by simply increasing the video signal amplitude because exceeding the display dynamic range in some video scenes causes unwanted disturbing effects. According to the present invention the video pictures are analysed framewise in real time and the parameters of a transfer function for contrast improvement are adjusted depending on the analysis results for the best subjective picture quality.

Abstract: A device for writing to and/or reading from optical recording media having different structures is described, for example, a device which is suitable both for writing to/reading from digital videodisks (DVD) and conventional CD's. Provision is made for measuring the intensity of each peak in the mirror signal while the objective lens is moving to the recording medium. The intensity e.g. at the instant of the positive-negative crossing of the focus error signal is taken in this case. The type of optical recording medium is determined from the time characteristic and/or the height distribution of the peaks. In order to identify the type of optical recording medium, different properties of the optical recording medium are taken into account, such as reflectivity of the corresponding reflective surface, reduced intensity modulation due to spherical aberration, time characteristic and the like.

Abstract: The invention relates to a television receiver, in particular a projection television receiver having red, green and blue monochromatic picture tubes, the images of which are projected onto a picture screen. Each picture tube is assigned a correction device comprising a convergence circuit. The convergence circuit is assigned a memory in which correction values for the convergence correction of the three picture tubes are stored. In accordance with the correction values, the convergence circuit generates control signals, which are output to at least one correction coil where each correction coil has one driver circuit. A correction current is applied to the associated correction coil to correct image defects visible on each picture tube.

Abstract: For audio coding, the MPEG-2 standard provides for a spatial representation by multi-channel reproduction. In order to ensure backwards compatibility with MPEG-1 signals, the signals of the multi-channel sound channels are matrixed. Before being matrixed, the audio signals generally have their levels reduced in order to prevent overdriving. In order to balance again the reduction at the encoder end, an option that is provided in the MPEG-2 standard is for a decoder to raise the output levels again. If, however, a transmission error then occurs in the multi-channel section, the decoder cannot carry out the reverse matrixing. In that case, only the MPEG-1-compatible signal component will be decoded. The auditory impression can therefore be disturbed in various ways during the changeover to MPEG-1 decoding.

Abstract: Head arrangements for appliances for longitudinal multitrack recording and/or replay of signals using a recording medium in the form of tape have stationary multitrack heads which have a large number of individual heads. The head arrangement according to the invention is formed with a first and a second head-mounting device, in which case the first head-mounting device is intended for engagement with the recording medium and has tape guides for the recording medium as well as in each case one recess for the arrangement of a magnetic multitrack head and for the arrangement of the optical scanner of a magneto-optical multitrack head which is arranged in the second head-mounting device.

Abstract: According to the invention, parts of the setting mechanism are integrated into the housing and/or setting mechanisms are arranged in such a way that they assume not only the setting function of one axis but also the guiding function of a further axis. The setting mechanisms are formed by eccentric bolts. Guiding pins serve for guidance in one axis. Clamping screws serve for fixing the adjusted axes. Slots serve as guiding aids in the various axes.

Abstract: In a method for fractal coding of signals, in which a domain block d is investigated for a range block r to be transmitted from an original signal, so that, after using the calculation rule r*=v·d+b, an approximated range block r* is generated, v·d being a linear function and b being an offset vector, the offset vector b in general has different components b=(b1, b2, . . . , bn) the offset vector b preferably being composed of weighted orthogonal basic functions of an orthogonal transformation.

Abstract: The present invention relates to a device for reading from and/or writing to optical recording media, which has a tracking unit, a four-quadrant detector, two summation points and a phase comparator for tracking in accordance with the differential phase detection method, and also two variable delay elements which can be set by a control unit. The device has improved compensation of the error in the track error signal and thus in the tracking signal. The error is caused by lens movement. An interference signal generating unit whose output is connected to the tracking unit and to a first input of the control unit, the second input of which is connected to the output of the phase comparator for providing error compensation.

Abstract: The invention concerns an apparatus for reading or writing optical recording carriers, the apparatus using the differential phase detection process for tracking purposes. This process exhibits shortcomings when optical recording carriers of different pit depths are to be used. The object of the invention is to design an apparatus of this type which can also be used with said optical recording carriers. This object is achieved in that delay members are disposed between the photodetector and phase detector. The apparatus according to the invention is used as a playback or recording apparatus for optical recording carriers, such as CDs, CD-ROMs, CD-Is, CD-Rs, DVDs, DVD-ROMs, DVD-Rs, etc.

Abstract: A method and arrangement for automatically setting a gain in a control loop using a tuning signal provides in a one method step, measurement of existing gain while a tuning signal is input, and then calculating consequent gain changes, which is to be carried out in the control loop, from a measured value for the gain. The reciprocal of the measured gain is calculated and the reciprocal of measured gain is used to calculate a gain change to automatically re-establish the gain.

Abstract: Circuits for driving a switching transistor (T3) with a driver stage (T2, T4, T5, L1), as are used for example in horizontal deflection stages of television sets or computer monitors, are known in a wide variety of embodiments. The invention specifies a power-efficient and cost-effective circuit of this type which contains a comparator circuit (T1), which monitors the voltage (UC) across the current input of the switching transistor (T3) for the purpose of monitoring saturation by comparing the said voltage with a reference voltage (UR), thereby effecting regulation. The comparator circuit may be realized, e.g. by a simple transistor circuit (T1), the reference voltage (UR) being applied to the control input of the said transistor circuit, the current input of the said transistor circuit being connected to the drive signal (US) of the driver stage, and the current output of the said transistor circuit being connected to the voltage (UC) via the current input of the switching transistor (T3).

Abstract: A stand alone CD player for reading data from a recording medium having data formatted in accordance with CD-like recording formats, for example, CD-ROM, CD-I and CD-V, stored thereon. According to the present invention, the playback of data from a recording medium having data in such a recording format is made possible by a virtual table of contents generated by the stand alone CD player. The virtual table of contents also enables sequential access to data stored on the recording medium that has a table of contents that cannot be read by the present CD player.

Abstract: A power transmission system with a gearwheel and a toothed rack, having an engagement securing system that ensures increased power transmission and protection of the toothing in the end region of the rack. According to the invention the engagement securing system comprises a lug disposed on the rack, which lug engages a guide connected to the gearwheel. In the exemplary embodiment the guide comprises a groove disposed on a disk coupled to the gearwheel. Advantageously, no additional individual parts are required. The range of applications includes an automatic transport securing system in recording or playback equipment for optical, magneto-optical or other recording media, as well as other rack drive systems that require increased power transmission in the end region of the rack.

Abstract: The present invention relates to a recording or replay device, and to a method for recognizing a focussing status. The object of the invention is to provide a method of this type and a recording or replay device, with the facility of producing significant astigmatism in the reflected light beam (15) simply and cost-efficiently without elaborate alignment. This object is achieved by the use of a birefringent element (23, 24). The invention is, in particular, suitable for use in a recording or replay device for writing to or playing back optical recording media (11) such as CDs, video discs, DVDs and the like.

Abstract: Method and arrangement for controlling the data stream in a vibration-resistant playback device. In vibration-resistant playback devices, it is known to write the data to a buffer memory continually at a doubled rate and to read out the said data at a normal data rate. If no vibrations occur, artificial returns must be effected. This leads to an increased power consumption. The present invention enables a reading rate which can be adapted to the averaging of the periods of time when the information medium can and cannot be read. In order to enable processing of the data stream with such a variable reading rate, reading from a memory is switched over between a normal and doubled data rates and the processing stages are likewise correspondingly switched over. As a result, only information data is stored in a downstream buffer memory, so that a lower capacity is sufficient or, with the existing capacity, a longer time span can be bridged during which no data can be read.

Abstract: The IEEE 1394 bus communication protocol has three layers: physical layer, link layer, and transaction layer. Typically, the transaction layer is realized by firmware whereas the other layers are implemented using chip sets. The link layer IC usually contains a FIFO having a capacity of e.g. 32k or 64k bits. Therefore, the link layer chip is the most costly part of a complete IEEE 1394 interface. Due to these cost reasons most ICs on the market are not bi-directional although the IEEE 1394 bus specification supports this feature. Incoming or outgoing data packets are intermediately stored in the FIFO. The current solution to this problem is to have two separate IEEE 1394 bus nodes assigned to the same application, the two nodes including two physical layer ICs and two link layer ICs.

Abstract: A method for monitoring and adjusting a motor current in a disk data drive allows to adjust a rotation speed of a disk to be as high as possible in order to increase an overall performance of the disk data drive. It comprises measuring the value of the motor current fed to the motor for an actual value of the disk rotation speed, comparing the value of the motor current with a nominal value of motor current at the actual value of the disk rotation speed, increasing the disk rotation speed to a new actual value of the disk rotation speed if the value of the motor current is substantially equal to the nominal value of motor current.

Abstract: A method for replacing parts of a digitally coded picture (11) is proposed. The digitally coded picture (11) may correspond to a sub-picture which is displayed on the screen of a television set (10). In the method, each line of the picture (11) is run length-coded. The replaceable parts of a line of the picture are run length-coded separately. The part which replaces the replaceable, original part of a line of the picture (11) is run length-coded in such a way that it has the same number of data units (data bytes) as the original part of this line of the picture (11). The replacement of the data for the run length coding words is carried out in a memory device (51). The replacement is possible in a simple manner by virtue of the fact that the original part of a line of the picture and the new part of the line of the picture have the same number of data units. Moreover, a device for carrying out the method is also proposed.