Abstract: The invention concerns a method for producing on a plasma panel faceplate, a dielectric coating comprising embossed patterns. The invention is characterized in that a vitreous coat is produced on the plasma panel faceplate; a mould bearing embossed patterns is applied on the vitreous coat, then the faceplate and the mould are heated until a creep effect of the vitreous coat is obtained which causes the latter to match the form of the mould, thereby enabling to produce simultaneously and with improved quality with respect to prior art, a dielectric coating bearing embossed patterns such as for instance barriers. The invention is particularly applicable to alternating plasma panel.

Abstract: The device for addressing a plasma panel comprising a video processing circuit (7) for processing the digital video data received, a correspondence memory (8) for transcoding these data, a video memory (9) for storing the transcoded data, the video memory being linked to column driver circuits (10) for controlling the column addressing of the plasma panel, is characterized in that the transcoded data have a greater number of bits than the digital video data received and in that the processing circuit (7) comprises means for differently coding identical values of digital video data received. The applications target plasma panel control devices.

Abstract: The present invention relates to a method for carrying out a magnesium oxide based deposition on the dielectric surface of a glass plate of a display panel. The method includes the creation of a mist from a metalorganic compound of magnesium dissolved in a solvent, the conveying of the mist to the dielectric surface of the plate, the evaporation the solvent when approaching the dielectric surface of the plate which is taken to a temperature of about 380° to 430°, and the pyrolysis of the metalorganic compound leading to the magnesium oxide based deposit on the surface of the plate and the evaporation of the organic radical of the compound, this deposit being practically waterproof. The method is especially useful in the manufacture of plasma panels.

Abstract: The device comprising a video processing circuit (7) for processing the video data received, a correspondence memory (8) for transcoding these data, a video memory (9) for storing the transcoded data, the video memory being linked to column drivers (10) in order to control the column addressing of the plasma panel on the basis of column control words, a control circuit (11) for the line drivers (12), is characterized in that the control circuit for the line drivers simultaneously selects at least two successive lines during the transmission by the column drivers (10) of at least one of the bits of the column control words relating to one of these lines.

Abstract: The invention relates to a process and device for scanning cells of a matrix-controlled display for the displaying of grey levels of a video signal, the scan being split up into sub-scans relating to each bit of column control words, characterized in that, when the coding of image does not activate the high-order bit, the processing sub-scan relating to this bit is allocated to the displaying of an additional item which corresponds to a bit of lower weight than the smallest weight of the column control word used when the condition is not fulfilled. The applications of the invention relate to matrix-controlled display devices using the principle of temporal modulation for the generation of halftones, especially plasma panels of the a.c. type with memory or d.c. type with memory.

Abstract: A projection system includes a projector for emitting a light beam; a screen and a first medium for converting a linear polarized form of the light beam from the projector to a quasi-circular polarized form of the light beam polarized in a first circular sense. The projector also includes a mirror for reflecting and phase shifting a quasi-circular polarized form of the light beam to a circular polarized sense substantially opposite of that exhibited by the light beam before being reflected by the mirror, and a second medium optically disposed between the mirror and the screen and for selectively converting the light beam between linear polarization and quasi-circular polarization.

Abstract: The present invention relates to a device for illuminating at least one surface, which includes a light source and a reflector in order to focus the light rays emitted by the source. In said device, the focal plane of the reflector lies between the light source and the said surface and it includes, positioned close to the focal plane of the reflector, a means forming a second light source.

Abstract: In a television receiver comprising a horizontal deflection circuit (2) associated with a flyback transformer (9), the horizontal deflection circuit comprises a switch (6) which is controlled by a control signal (Hdrive) generated by a deflection control circuit (1). The deflection control circuit generates a phase difference signal (Vcomp) which is a function of the phase difference of a horizontal synchronisation pulse and a flyback pulse and generates the control signal (Hdrive) as a continuous function of the phase difference signal (Vcomp). The deflection circuit is further arranged to generate at least one discrete phase jump of the control signal (Hdrive) when the phase difference signal (Vcomp) lies outside of a range of preset values (Vlow, Vhigh).

Abstract: The invention relates to a process for protecting an information item transmitted from a security element to a decoder and a protection system using such a process. The information item is protected by encrypting within the security element the information item to be transmitted to the decoder and by decrypting this information item within the decoder. The invention applies to conditional-access systems.

Abstract: A device for addressing a matrix screen such as a screen of the LCD or plasma type having a memory stage receiving, via a demultiplexing stage a plurality of sequences of digital data representing the previously digitized luminance video signals, and delivering the luminance video signals to a multiplexing stage designed to select a sequence of digital data corresponding to a given combination of subpixels from amongst the plurality of sequences of digital data previously stored in the memory stage.

Abstract: The subject of the invention is a communications device connected in parallel with at least one item of communications apparatus on a transmission line (L1, L2). The device and the apparatus conform to a given template in terms of DC components. The device in accordance with the invention is characterized in that it comprises means (18, R1, R2, R3, D5, DZ) setting the operating point (X) in terms of DC component of the said device alone outside regions of the said template where the DC component of the current may be zero, means (R2, D6, D7, R4, 19, 20) of determining the DC component of the current flowing in the said device, means (20) of detecting a variation in the said DC current component. The invention applies particularly in the field of communication via the switched telephone network.

Abstract: The protection circuit comprises a storage capacitor which is coupled with a terminal of a secondary winding which charges said storage capacitor during the on-interval of the switching transistor. During the off-interval of the switching transistor the charge of the storage capacitor is fed to the driver stage or the control capacitor for closing or keeping closed the switching transistor when one of the secondary windings has a short circuit.

Abstract: An analog to digital converter transposes the input signal into two differential signals, which are applied to respective inputs of a differential comparator. The output of the differential comparator is linked to the input of the analog-digital converter by a circuitry loop for restoring a DC component of each of the differential signals at the mid-voltage of the conversion range of the analog-digital converter.

Abstract: Supplementary grid blanking and spot burn protection are provided in a receiver/monitor (10) by a grid bias control circuit (50) including a blanking signal generator (60) that produces a blanking output signal (S1) devoid of any picture representative component whenever a vertical blanking signal (VB) or a horizontal blanking signal (HB) is present. A capacitor (C1) strips DC from the blanking signal and the resultant signal (S2) is applied to a modulation input (84) of a grid bias generator to produce an output grid bias reference voltage (Vr) modulated by the AC component of the blanking signal. The reference voltage (Vr) is coupled via a spot burn protection circuit (100) and a grid coupling circuit (120) to the control grids of three projection kinescopes (16, 18, 20).

Abstract: A process for addressing cells of a plasma panel includes the step of coding the grey levels NG1 and NG2 relating to an item of information regarding the luminance of two cells situated in the same column and in two adjacent lines I and I+1. The grey levels NG1 and NG2 are coded as a first control word corresponding to a common value VC and as a second control word and a third control word corresponding to specific values, VS1 and VS2. The coding is such that, NG1=VS1+VC and NG2=VS2+VC. The process further includes the step of transmitting the bits of the first control word on the column inputs by simultaneously addressing the two lines I and I+1 in respect of the selection of the corresponding cells.

Abstract: The device has reference current sources (T71, T72, T7M) which are arranged in such a way that the sum of the currents flowing through each of the said sources is equal to the input current (IIN, I′IN) and output current sources (T81, T82, T8N), in each of which the current flowing through the reference sources is duplicated and which are arranged in such a way that the sum of the currents flowing through the output sources is equal to the output current (IOUT, I′OUT). The number of reference sources (T71, T72, T7M) and output sources (T81, T82, T8N) which are connected is controlled by the digital signal (200) and determines the gain of the device. Application to the circuit for processing the signals output by a read head of an optical disc reader apparatus.

Abstract: A block based signal compression system, as for example for coding video signal, and employing quantization of codewords or transform coefficients includes circuitry for adaptively controlling the quantization. Adaptivity of quantization is made a function of several parameters. One parameter is coding cost or bandwidth, wherein coding cost is generated on a macroblock basis but averaged over a window of macroblocks centered on a macroblock currently to be quantized. Another parameter is block or macroblock motion attributes, wherein block motion attribut values are used to modify the quantizing function.

Abstract: A device for estimating motion between a current image and a previous image by block matching, the images being split into blocks. The device includes a processing circuit for each candidate motion vector and at least one memory. Each processing circuit calculates errors between a block of the current image and the block designated by a respective candidate motion vector in the previous image. The processing circuit successively receives pixels of the current image according to a line scan at a first input and corresponding pixels of the previous image identified by the associated candidate motion vector at a second input. The processing circuit calculates partial sums at the end of line of each block of the current image corresponding to accumulated errors for this block. The processing circuits further include an output for delivering the partial sums and a third input for receiving the partial sums.