Abstract: A method for the remote control of at least one electronic device (10 to 25) is proposed in which the control data are transmitted from a remote control device (27) to the electronic device (10 to 25). In the method, information data at least regarding the remote control functions of the electronic device (10 to 25) to be controlled are transmitted to the remote control device (27). These information data are stored in the remote control device (27) and called on during a control operation in order to select and transmit the control data necessary for the respective control operation. At least the device identification number (GID) and the device type are transmitted to the remote control automatically, for example after the connection of the electronic device to the power supply system.Furthermore, an apparatus for the remote control of an electronic device is proposed, as well as an electronic device.

Abstract: A device for corrected-focus scanning of information while recording on and/or replaying information from a recording medium is based on a radiation source which provides a scanning beam, a focusing objective lens and a radiation-sensitive detector system. A diffraction element for deriving a focus error signal is arranged in the space between the focusing objective lens and the detector system, at a predetermined, fixed distance, the diffraction element being designed such that two focus planes result which are physically separated from one another. The detector system is located between the separate focus planes such that the size ratios, which change in the event of defocusing, of the symmetrically imaged focus spot can be used to derive the focus error signal.

Abstract: In the case of various recording systems based on the helical-scan method for magnetic tapes, a pilot-tone principle is used for tracking control, generally using two pilot tones which are recorded on the helical tracks respectively in series of four: pilot tone F1, no pilot tone, pilot tone F2, no pilot tone. Known methods for determining the pilot-tone amplitudes use narrow-banded band filters, a control signal being generated by forming the difference between the amplitudes. On account of the weak pilot tones, this requires very narrow-banded filters with good dynamic properties.According to the invention, a quadrature mixing has the effect of converting the two pilot tones into the baseband, whereby the filtering is performed in the low-pass range and a control signal can be derived from the difference between the pilot-tone amplitudes thus determined.

Abstract: In a switch-mode power supply, a transformer is used to transmit power during the forward-sweep time. The transformer is also used to transmit a control or regulating variable during the flyback time.

Abstract: A digital detector circuit for recovering the bit timing of a data stream with a PLL includes a digital phase detector and a digital pulse length detector whose output signals are added and integrated, and the result is used for controlling the oscillator frequency. The output signal of the pulse length detector is determined by a corresponding algorithm, one slow and two fast, with direction-dependent output signals of the pulse length detector being generated.

Abstract: A control unit sets a first reading speed and a second reading speed of the information stored on the information medium as a function of a predetermined occupancy of the buffer below its storage capacity. The drive motor, which produces the reading speed, is connected via a switch to the driver which drives it and, during a reduction of the reading speed to a predetermined value or until the occupancy of the buffer falls below a predetermined occupancy, the power supply to the drive motor which produces the reading speed, is reduced by means of the switch for the purpose of reducing the power consumption.

Abstract: There is disclosed a communications terminal, including a video telephone, for transmitting and receiving video and audio. The terminal includes video recording apparatus and video reproduction apparatus with the video recording apparatus being switchable into an "off" mode by operation of a flap. In order to use the transmission capacity of the communications terminal even when the flap is closed, an image which already exists in a video memory is transmitted. A changeover is automatically made to the video memory by operation of the flap.

Abstract: Apparatus for interposing additional optical elements in the optical path of an optical read/write device includes said additional element mounted on a carrier pivotally mounted on a lens carrier which is subject to lateral translation. Stops on the carrier to which the additional element is mounted engage actuators arranged at the limits of lateral travel of the lens carrier, which limits are beyond the recordable areas of the recording medium. The engagement of the actuators with the carrier causes the carrier to pivot and either insert or remove the additional optical element in the optical path of the apparatus. Magnetic retainers are included to prevent the additional element from moving from the desired position.

Abstract: In digital, magnetic and optical storage systems for audio/video/data, a Viterbi detector is extended by a control output, and a PLL is controlled by a variable delay line at the output or inside of the PLL.

Abstract: A videophone system having an electronically controlled shutter to vary the amount of light falling onto the target by a shutter, e.g., for a greater or lesser length of time during a short exposure time rather than b y means of a controlled mechanical aperture. Data reduction is used for the transmitted signal, a control circuit is used for the exposure time, and the mains power supply, which produces ambient light, are coupled by means of a PLL circuit so that the exposure time occurs at the same phase of the mains voltage. In this way, interference occurring when data reduction is used for the signal to be transmitted is avoided and macroblocks are not formed when no difference signal is present.

Abstract: The present invention to provides for information carriers of different storage densities, a recording and/or playback device which is compatible or can be used for different optical information carriers despite a functional relationship which to be satisfied between the size of the information memory location or pit size and the size of the light spot, without changing the wavelength of the laser used or changing the numerical aperture of the objective lens. In order to operate optical information carriers of different storage densities, use is made of an optical system which has a wavelength and numerical aperture matched to the highest storage density, provides a plurality of secondary beams matched to the respective track width, and has a number of secondary beam detector pairs which corresponds to the number of different information carriers.

Abstract: A method for the production of picture sequences for a fast search operation in a film play-back device (10, 40) is proposed. In this case, the video data of the individual pictures of the film are stored in digitally coded form in a storage unit (11, 41). The method is distinguished by the fact that 1. the video data of the pictures are read out from the storage unit (11, 41) at an increased speed, that 2. the read-out video data are decoded at an increased speed in a decoder (18, 43), that 3. only the video data of specific individual pictures are selected from the decoded video data and are fed to an encoder (21, 45) which operates at a regular speed.

Abstract: The invention relates to a method for recording longitudinal track bundles on an information medium. The method involves recording tracking information in special tracks in said track bundles. The special tracks are contiguous between each other. When recording a new track bundle a recording and/or reading head may be positioned using tracking information contained in special tracks of a previously recorded track bundle. Several examples of patterns used for coding tracking information in the special tracks we described.

Abstract: A reproducing and/or recording device for reproducing, or for recording on, an optical recording medium, having a tracking sychronization circuit (1), which has a variable center frequency generator (12, 13). The tracking synchronization circuit (1) can be operated with different center frequencies depending on application, and this has the advantage that identically designed tracking synchronization circuits (1) can be used for different purposes. It is advantageous that adaptive adjustment of a center frequency once prescribed is additionally possible during operation, thus increasing the capture range of the tracking synchronization circuit.

Abstract: The invention relates to a method and a device for producing a scanning device, also termed a pick-up, for optical recording media, which can be produced with a low outlay and thus cost-effectively, and in comparative terms has a low tilt of the objective lens and improved guidance properties. According to the invention, during the connection of an objective lens holder and actuator base plate, a prestress is applied to wires provided as elastic support of the objective lens holder on an actuator base plate. Scanning devices produced according to the invention for optical recording media have a low tilt of the objective lens and improved guidance properties.

Abstract: Electronic circuit having a digital controller operation of a synchronous motor.Precision motors for driving, for example, a video head drum in video recorders are normally designed as externally commutated synchronous motors. These motors are driven with square-wave voltages by a digital controller (CON), whose circuitry can easily be implemented.The object of the present invention is to specify an electronic circuit of the type mentioned initially for controlling a synchronous motor, which enables good synchronism and the motor to be operated with little electrical noise.This object is achieved in that the synchronous motor is driven by sinusoidal signals, a separate control signal from the controller (CON) influencing the amplitudes of the drive signals (U1, V1, W1). A regulating signal for regulating the synchronous motor is produced by a sensor (GE) which is arranged on the synchronous motor, which regulating signal produces a fixed phase relationship between rotor revolution and drive signals.

Abstract: In order to produce synchronous control signals of a video recorder, in particular of a digital video recorder, a position pulse of the scanner motor, which coincides with the beginning of the video frame, is used as time zero point. Time markers in which changes in the control signals take place are calculated starting from this time zero point. These time markers and the bit patterns occurring at these time markers are stored as data words in a data field and, for corresponding time markers, the corresponding data word is output in parallel, that is to say synchronously. A realization is possible by means of a microcontroller and a controllable output memory, the microcontroller containing the functions of capture register, timer, calculation unit and comparator.

Abstract: A control unit, stores addresses of a write pointer of a buffer in the case of the last valid subcode information and starts with a synchronization byte following an interruption. The synchronization byte is provided for the synchronization of the data stream in the buffer, an item of address information which identifies the interruption location in the data stream, the starting point of the synchronization being formed by a valid subcode, the address information being used as a reference both for the location of the interruption on the information medium and for the last valid data in the buffer and the writing in the buffer. This is done so that uninterrupted reproduction of information is provided despite vibrations in the playback device.

Abstract: For the transmission of additional data on a television channel the lines of the vertical blanking interval are used. It is intented to improve program information by so-called electronic program guides, which are based on the transmission of a large database. For these EPGs the additional data shall be broadcasted within the teletext data stream in a compatible manner. The EPG data are splitted into two data streams, wherein the transmitted data are organized in data blocks. Data blocks from different streams may interrupt each other. According to the invention the data pages (A, B) are stored sequentially in two different buffers (PA, PB) and processed alternatively. The blocks of the pages transmitted in the first stream are stored in a first block buffer (BB1) and the blocks of the pages transmitted in the second stream are stored in a second block buffer (BB2).

Abstract: A device for reading from or writing to an optical recording medium is disclosed which has at least two information carrier layers spaced apart from one another, as well as a light source, an optical unit and a detection unit. The device permits a plurality of information carrier layers to be read from and/or written to simultaneously using light of a single wavelength. A partial beam generating element emits two polarized beams which differ in terms of polarization direction and propagation behaviour.