Abstract: A speech based man-machine communication system is given, comprising more than one controllable device provided with speech synthesis function. Each of the devices in question is provided with its own unique voice pattern. The devices are connected via a bus, so that a central authority handles all the requests from the user. Because the user uses his natural language, commands can be ambiguous. Therefore an algorithm for handling ambiguous situations is provided.

Abstract: The invention relates to a process for data certification as well as to the system implementing the certification process.The certification of the data is performed by scrambling.An authority independent of the entity which controls the data source and of the user(s) for which these data are intended, scrambles the data with the aid of control words and encrypts the control words with the aid of an encryption algorithm with key K.So that a user or the users can descramble the data scrambled by the independent authority, a certification verification device containing the encryption key K is supplied to the user or users under the control of the independent authority.The certification process and the system associated therewith apply more particularly to conditional-access systems.

Abstract: The conditional access system of the present invention allows a service provider to supply services, which may be scrambled by a control word, only to those users who have acquired entitlements to these services. The control word is supplied in Entitlement Control Messages (ECM) after having been encrypted using a key. The entitlements of each user are forwarded in Entitlement Management Messages which contain the key. The conditional access system verifies and validates the ECM and EMM prior to processing the control word.

Abstract: The invention is a process and apparatus for estimating a bit budget in a circuit for compressing digital data, especially digitized television signals. Signals represented by N-bit coded samples, are estimated based upon the probability of a bit of given order having a given value (0 or 1) out of M binary words representing M samples of the signal. An entropy calculation is performed on the basis of the probabilities corresponding to the N bits with the sum of all the entropies corresponding to the desired estimate.

Abstract: The system includes a plurality of decision units, at least one verification unit, and at least one counting unit, the units being functionally and structurally separate from each other. Each decision unit includes means for producing a source information item and an identity information item, and means for enciphering this source information item in such a way as to render it essentially indecipherable by the verification unit but decipherable by the counting unit. The verification unit includes a file which includes the identities of the decision units, means for checking the identity of the decision unit from which an incoming message originates, and means for compiling an anonymous derived message which is essentially devoid of any identity information item decipherable by the counting unit.

Abstract: The disclosure relates to a method of synchronization of clocks wherein, in a system including a digital decoder of a receiver equipped with a sampling clock and a digital encoder of an transmitter also equipped with a sampling clock, said method includes the following stages: in the transmitter, coding by packets of samples of a signal by time intervals of predetermined duration and triggering of the transmission of a data frame when a packet of data is ready to be sent; in the receiver, detection of start of said frame, and generation of a reference signal following said detection, said reference signal being used to correct the clock of the receiver.

Abstract: A radiation emitting device, such as an LED, is optimally driven in dependence on the value of a carrier frequency of a signal to be transmitted. The current provided to the radiation emitting element is controlled responsive to the carrier frequency. When using an LED, the current value is increased with decreasing duration of current flow. The apparatus is usable for remote controls suitable for controlling two or more devices.

Abstract: A process for converting interlaced frames into progressive frames comprising a change of frame frequency by interpolation and motion compensation, wherein when a motion vector associated with a pixel to be interpolated is non-zero or when the motion vector is zero but the confidence accorded to this vector is less than a given threshold, the interpolation of the pixel of a frame situated temporally between two input frames is carried out by a median filtering pertaining to the values obtained by a first motion compensated linear temporal filter, a second motion compensated linear filter, and a motion compensated median temporal filter.

Abstract: A display device having a backlighting system supplying collimated light, a transmissive electro-optical modulator of the liquid crystal display type and a means for distributing the light angularly. The distance between the means for distributing the light angularly and the display is chosen so as to obtain a spatial filtration effect. A layer of colored filters is positioned between the display and the means for distributing the light angularly.

Abstract: The disclosure concerns a procedure for insertion of samples representing digital data from a first source having a first bit rate in a digitized signal from a second source having a second bit rate, wherein the second bit rate is greater than the first bit rate, and each data of the first source is associated with at least one sample of a series of samples at the second bit rate, the samples being presented to a polyphase filter for which a set of coefficients is associated with a specific phase error previously introduced by said associations, the filtered samples being included in the digitized signal. The invention also includes a device that implements the above insertion procedure. The invention is applicable notably in the field of insertion of Teletext data into a digitized video signal.

Abstract: The circuit for the digital filtering of IF intermediate frequency video signals comprises an A/D (analog/digital) converter and a Nyquist filter (N); an analog prefilter, suitable for selecting the desired channel, is placed upstream of the A/D converter. The Nyquist filter (N) is a digital filter placed downstream of the A/D converter, composed of two IIR filters (15, 16) placed in cascade, one (16) of these IIR filters being produced in non-causal form with spectrum conjugate to the other IIR filter (15) produced in causal form, and of an FIR filter (17) in series, for correcting the IIR filters.

Abstract: The present invention relates to a process and a device for the wireless transmission of a signal S.sub.1 between a transmitter and at least one receiver.According to the invention, at the sending end:a first carrier S.sub.2, of frequency F.sub.2, situated in the VHF (Very High Frequency) range, is frequency-modulated by the signal S.sub.1 to be transmitted, and thena second carrier S.sub.3 of frequency F.sub.3, situated in the SHF (Super High Frequency) frequency range, is amplitude-modulated by a modulating signal S.sub.2m. resulting from the frequency modulation of the carrier S.sub.2 so as to transmit an amplitude-modulated signal S.sub.3m to the receiver,and at the receiving end:amplitude demodulation of the signal S.sub.3m is performed so as to recover the signal S.sub.2m, and thenfrequency demodulation of the signal S.sub.2m is performed so as to recover the signal S.sub.1.

Abstract: A digital sample filtering device comprising storage device including ROM and RAM memory for storing in an interlaced manner, coefficients of at least two filters along with for each coefficient, data indicating to which of the filters the each coefficient belongs; a multiplier for multiplying at least one of the coefficients by a sample and an accumulator for adding the partial sums of the multiplication results for each of the filters.

Abstract: A video receiving device (A) that includes a circuit for receiving first video signals from a remote transmitter, a circuit for receiving second video signals from another video receiver (TVS), a circuit (TU1) for automatic searching for transmission channels, and a circuit (PC) for phase comparison between the vertical synchronization signals of the first video signals and the vertical synchronization signals of the second video signals that can output an "outphasing" signal that is used for controlling the operation of the automatic channel search circuit, wherein the video receiving device (A) also includes a control circuit (CC) that enables the video signals that it is receiving to be displayed for a pre-determined time on the other video receiver (TVS). The invention is applicable notably to the programming of video recorders, and to the automatic tuning of such a recorder to the channel being viewed on a TV receiver in order to enable simple and immediate recording of this channel.

Abstract: The invention relates to a device for blockwise estimation of motion. This device includes on the one hand a matrix array (300) for calculating an error function, the said array including storage elements (S, 406, 407) for plural blocks (a, a') of current pixels and means (403) for switching between the storage elements corresponding to the various blocks and on the other hand a memory (801) for feeding the said array with pixels of a search window, linked to the said array.The device according to the invention is characterized in thatthe said memory (801) is a random access memory,the said memory contains a band of the search window corresponding to the entirety of the current blocks stored in the array (300),the said device including means (812) for read-addressing partial sections of the said band of the memory as a function of the block processed (a, a') by the said array, the said sections being introduced column by column into the said array.

Abstract: Circuitry to control a power supply of a degaussing coil of a cathode ray tube, said degaussing coil is coupled to a main voltage supply through a switching device the circuitry has inputs coupled to a direct source of current of a switched mode power supply, the switched mode power supply comprises a switched mode transformer with primary windings coupled to the main source of voltage, and secondary windings and the switched mode power supply is switched in a first range of frequencies when the power supply is in a "standby" mode and in a second range of frequencies when the power supply is in an "on" mode wherein said circuitry comprising a detecting circuit which detectes a change in the range of switching frequencies when the power supply is switched from standby to on, the detecting circuit having an input coupled to a direct current source being downstream of a primary winding of the switched mode transformer and an output coupled to an input of a control circuit of the switching device the control circ

Abstract: When a given row in an array of a liquid crystal display having a toggling backplane voltage is de-selected, the row select line voltage also toggles to prevent capacitive current in the pixel capacitance. The row select line driver includes a pair of transistors coupled in a push-pull configuration. The pair of transistors are responsive to a control signal that is produced in a corresponding stage of cascaded stages of a shift register. The pair of transistors form a buffer stage that prevents the toggling voltage developed in the row select line when the row is de-selected from affecting the operation of the shift register.

Abstract: In a vertical sawtooth generator of a vertical deflection circuit, a first comparator generates an output signal when a retrace portion of a sawtooth signal is at a first magnitude to initiate a vertical trace portion of the sawtooth signal. An amplifier responsive to the sawtooth signal and to a reference signal generates a feedback current at a time that occurs between the center of vertical trace and the end of trace and away from the center of trace. The feedback current is determined in accordance with a difference between the sawtooth signal and the reference signal. The feedback current is coupled to a first capacitor to develop a gain control voltage. The control voltage is applied via a voltage-to-current converter to an integrating capacitor to develop in the integrating capacitor the trace portion of the sawtooth signal. The control voltage is initialized during a power start-up interval.

Abstract: A device for regulating the luminance signal and chromanance signals of a video image to be converted into red, green and blue color signals. The device includes a conversion matrix and a device for regulating an amplitude of the luminance signal, the blue color difference chromanance signal and a red color difference chromanance signal to be modified by a user adjustment control. The device further includes a device for preventing the color signal having the highest value at the output of the conversion matrix from being able to exceed a saturation value substantially equal to a percentage, preferably 70%, of the white level of the image signal when the color signal reaches the saturation value.

Abstract: A plasma display panel is formed by a front plate and a back plate spaced apart from one another so that a discharge space is formed to accommodate a plurality of light generating display cells. To increase the luminance on the front side of the plasma display panel a mirror surface or a plurality of mirror surfaces is provided at the back side of the plasma display panel and/or at side-walls of cells of the plasma display panel.