Abstract: The invention concerns a high storage capacity ROM-RAM disk and a process for reading and writing to the ROM-RAM disk. T he aim of the invention is to devise a ROM-RAM disk and a process making it possible to read ROM and RAM simultaneously, to read the ROM area and at the same time write to the RAM area and to provide the largest possible volume of memory. The invention comprises two alternative designs. In a first design a ROM-RAM disk contains an area having both ROM and RAM memory structures as of a certain radius or diameter, establishing therein, at a constant rotational speed, a scanning/writing speed which ensures a reading/separation of the data stored in the ROM-RAM structures. In a second design, the available storage area is taken up entirely by a ROM-RAM storage area, where RAM memory structures have a reduced data rate in order to form, a length of memory structures necessary for separating the data stored in the ROM-RAM storage area.

Abstract: In a plasma display screen them is a circuit which alternately applies a positive and negative voltage to the general capacitance of the screen or panel for a reset process. In the current path there is an inductance to ensure the recovery of the energy to the total capacity. The aim is to improve the drive and the erase process of a pixel in such a circuit The capacity (Cp) is cyclically connected via a third switch (T3) to such a third operating voltage that the voltage (UCp) at the capacitance (Cp) has a period of zero voltage between those of positive and negative voltage. Especially for a control circuit for a plasma display screen for a television receiver.

Abstract: A reproduction and/or recording device for optical recording media which is compatible in respect of varying storage density, despite an interdependence between pit or domain size, and the light spot size. Use is made of a track guidance signal generation device which can be changed over according to the storage density type and is connected to a detector which can be used for recording media of varying storage density, i.e. in the form of the standardized CD, minidisk or MOD, and for optical recording media, which have a comparatively higher information storage density, or smaller track spacings and smaller dimensions of the pits or storage structures.

Abstract: A television receiver or video monitor of the back-projection type, in which a projector forms an image which can be observed on a visual display screen by rear illumination after reflection on a deflecting mirror. The projector includes in immediate proximity to the visual display screen and parallel to the latter, a reflection-transmission screen comprising a Fresnel surface, the projector, reflection-transmission screen and deflecting mirror being configured together to form an optical system such that the reflection-transmission screen reflects the rays directly emanating from the projector in the direction of the deflecting mirror and transmits these rays after their reflection on this deflecting mirror. The Fresnel surface includes striations of triangular cross-section, these striations locally forming prisms and capable of reflecting the rays which strike them when the angle of incidence of the rays are greater than a predetermined value and of transmitting the rays in an opposite case.

Abstract: The disclosure concerns an electronic device, for example a radio-alarm clock, that can be powered from the mains power supply or from batteries and can operate without interruption when changing from one of these power supplies to the other. It comprises a support connected to the mains and a mobile part that can be placed in electrical contact with said support and that includes at least one electronic circuit requiring power. This electronic circuit is powered from the mains via a first diode when said mobile part is placed in electrical contact with said support, and is powered by at least one battery via a second diode when said mobile part is removed from said support.

Abstract: Motion vectors resulting from block matching are corrected for periodic structures by taking a more reliable vector from an edge of a moving object containing the periodic structure. This is done by calculating and comparing different error combinations to identify periodic structures and replacing a current motion vector with one of an adjacent pixel block either from the block to the left or from the block above, which ever yields the smaller error in the current block, or by taking a combination (e.g., mean) of both vectors. Advantageously, artifacts such as phase reversal of information in interpolated fields due to the presence of an erroneous vector in a periodic structure are reduced and very little additional processing is required after the block matching itself.

Abstract: Components for analog or digital input signals are in each case connected by switchable means to a controllable oscillator. The switch condition of the switchable means is set automatically and/or manually as a function of the input signal.

Abstract: In the case of a motor controller for electronically commutated DC motors, an additional current and/or an additional voltage is passed at the commutation instant to that winding of the motor which is active at that time, in order to prevent torque drops. In order to compensate for torque drops at different motor loads, the duration and/or amplitude of the additional current and/or of the additional voltage are/is determined from the actual motor load.

Abstract: Multi-media documents, in the form of digital signals, are fed into a multiplexer/coder by several sub-channels, which are time multiplexed. A control signal is added and the combined signal is modulated into a transmission signal at the transmitter side. At the receiver side, the transmission signal is processed up to the output of a tuner like a normal signal for television. After the tuner, the signal is demodulated, digitized, demultiplexed, and the control information of the control signal is extracted from the bit stream so that by monitoring said control information signal provided with the transmission, a transmission channel decoder enables a multi-media player to read a distributed document according to the program of the user.

Abstract: Equalizers, used for equalizing distorted signals, are calibrated with the aid of the so-called "eye" pattern on the oscilloscope. Data bits are traced with their edges above one another by triggering to the amplitude so that an "eye" opening is produced. The "eye" is wide open and sharply delimited in the case of correct equalization. However, this method does not provide for automatic calibration of the equalizer. In order to automatically calibrate an equalizer in an optimal manner, a Lissajous figure is formed from in each case of two successive samples of the signal to be equalized. A fuzzy logic control loop compares the Lissajous figures generated with a circle in the case of a sine oscillation and with a square in the case of a square wave oscillation. From this comparison, the fuzzy logic control loop derives the parameters for the equalizer. The equalizer is optimally calibrated when a circle or, respectively, a square is formed as Lissajous figure.

Abstract: The disclosure relates to an LCD projector illumination system that optimizes the illumination through a liquid crystal screen as well as through the aperture of the system's objective, wherein the shape Zr,.beta. of the reflector is described by a set of elementary surfaces dS each of which is associated with a function Z(.rho.), corresponding to a median plane (r,.beta.) to be illuminated, defined by the distance r between the center and the edges of said screen and the angle .beta. between the horizontal plane and this median plane, the inclination of each elementary surface dS being computed by interpolating said functions Z(.rho.) with a function Z(x,y).

Abstract: When a power supply unit supplies power to a plurality of power amplifiers, an appreciable power loss is produced in the power supply unit and in the amplifiers. According to the present invention, the output voltage of the power supply unit is regulated so that it is high enough at any instant for the amplifier which at that instant has an output signal having the largest amplitude.

Abstract: To reduce the time required to access serially transmitted teletext data, such data is often stored in memory. The present invention reduces the otherwise required memory size by storing the characters in proportional form and/or with duplicated characters not stored a plurality of times but stored with information on the number of times a character is duplicated.

Abstract: An optical scanning device having a holographic optical element for receiving a scanning beam which has been influenced by a recording medium. One aspect of the invention is to use an optical spatial filter to obtain the information signals. A further aspect is to image the entire area of the scanning spot on only one detector and to use the complete light component, as a result of which the power component is increased and the requirements for adjustment of a plurality of elements with respect to one another are reduced.

Abstract: A tuner is used in common for both terrestrial and satellite television reception. A second mixing stage is switched as a mixer for signal conversion into a second intermediate frequency during terrestrial television reception and is switched as a component of a FM-PLL demodulator during satellite television reception. The tuner is particularly suitable for television receivers and video recorders which receive signals from both a terrestrial antenna/signal source and from a satellite antenna/signal source.

Abstract: A helical antenna system for receiving simultaneous signals with different polarizations, with the aid of helical feeders and without gain degradation. Two or more helical feeders are provided for each polarization direction.

Abstract: The disclosure is a device for mechanical assembly of a flexible cable in a cylindrical orifice, including a cable grip member slotted axially and carrying at least two helical threads on the outside and protuberances on the inside. The cylindrical orifice has a thread that engages the threads of the cable grip member. To fit the cable, the cable grip member is pushed axially into the cylindrical orifice, then the flexible cable is inserted axially in the cable grip member. Removal of the cable is achieved by unscrewing the cable grip member from the cylindrical orifice. The protuberances and the compression effect produced by the helical threads pulling on the thread in the cylindrical orifice when axial tension is applied to the cable assure efficient gripping of the cable.

Abstract: The programming of a broadcast receiver is selected from the display and the mapping of the required numbers is fully automatic. The user enters a code and the VCR decodes the entered code to determine the corresponding channel. The VCR then checks to determine if this channel is mapped. If not, the VCR prompts the user to identify which program one wishes to record. A picture on the TV, in a mixed mode, can be used for this, i.e., the TV program selected is shown on the background behind the text. The user uses keys on the remote control to scroll through the list of channels to find the program one wants to record. Once determined, the VCR will automatically map the correct three digit numbers for the program selected. In this way, the user need not know what the selection number represents.

Abstract: A more rapid charging of an integrating capacitor of a PLL is provided when large frequency changes are desired. In one embodiment, the phase locked loop (PLL) circuit sinks or sources current to charge or discharge the integrating capacitor. A threshold voltage proportional to a current through the capacitor turns on a circuit which sinks or sources more current of the proper polarity to the integrating capacitor from an external source until a PLL lock is achieved. Once the lock is achieved, if a small correction current is required by the PLL, the small correction current is below a threshold required to actuate the augmenting circuit, and the PLL loop behaves in the usual manner as if the augmenting circuit were not present. In another embodiment, the integrating capacitor is reduced in value by switchably connecting a second capacitor in series with the integrating capacitor so that the total reduced capacitance of reduced value can be charged more quickly.

Abstract: In laser feedback systems of an optical memory the most suitable feedback gain value depends on the type of optical disks used. According to the invention a system and a method is provided which finds by way of an iteration a suitable maximum feedback gain value so that the feedback system does not oscillate. The method consists in starting with a low gain value for driving a laser diode, increasing the gain value by small amounts until an oscillation detecting unit detects that the laser feedback system is oscillating. Then the gain value is reset to the previous value or a little bit more. Then the laser feedback system is again in a non-oscillating area with a suitable maximum gain value. This iteration is performed by a system consisting mainly of a laser diode, a photodiode for detecting the reflected light, and an oscillation detecting unit which controls a gain controller. This gain controller sets the gain on a multiplier which drives the laser driver for the laser diode.