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: 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: 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: Disclosed are a method for the control of an image display screen displaying half-tones and a display device implementing this method. The disclosed method is used to control an image display screen of the type having cells arranged in rows and columns and working either in a state known as an "OFF" state or in a state known as an "ON" state in which they are activated and produce light. The method consists in activating the cells of each row during sub-periods of different duration, with orders of distribution of the sub-periods that are different between two successive rows. This results in a reduction of the amplitude of the variations of a load constituted by the cells in the <<lit>> state of these two consecutive rows. Application inter alia to alternating plasma panels.

Abstract: A method for the control of a display screen whose pixels are cells producing light is used to minimize certain image defects known as excess brightness defects caused by major variations in the number of cells activated. For this purpose, the invention operates on the sub-division of the activation times of the cells during a given cycle time to reduce a time during which cells, selected as a function of their luminance level, are the only ones to be activated. The disclosed method can be applied especially to the control of alternating type plasma panels.

Abstract: The present invention relates to a backlight system for transmissive electro-optical modulator comprising: at least one source of light rays; at least one reflector for returning the light rays along a first direction referenced z; a means of transmission of light, positioned at the exit of the reflector in such a way as to transport the light rays along the z direction, one of the faces of the transmission means lying along the z direction comprising a micro-prismatic structure which specularly reflects the light rays and extracts them from the transmission means substantially along a second direction referenced x perpendicular to the first direction and a collimation means (20) situated between the source of light rays and the transmission meansz. The said collimation means (20) comprises an entrance face (21) inclined with respect to the first direction referenced z. The invention applies more particularly to retroprojection.

Abstract: Dolby AC-3 and MPEG-2 audio permit the transmission of audio signals in packet form, via more than two independent audio channels. If a reproduction device has only a two channel audio decoder an external multi channel audio decoder may be used for multi channel audio reproduction. In this instance, packetized signal is received by a first decoder and is decoded for a first mode of reproduction and applied to a reproduction device. The received signal is unpacked in the first decoder and stored in memory. The stored signal is reformatted for application to a second decoder for decoding and reproduction according to a second mode of reproduction.

Abstract: A process for reading binary information written on a carrier. The carrier has at least one track and the binary information is written onto the carrier at a frequency Fbit. The process includes the step of reading binary information at the sampling frequency F.sub.e to form a succession of successive read samples SAM(k) of the same track. SAM(k) is the read sample of order k, each read sample having a phase .phi.(k) lying between 0 and 2.pi.. The method further includes a step of interpolating to make it possible to calculate an interpolated sample I(k) with phase equal to .pi. which corresponds to read sample SAM(k) on the basis of the read sample and on the i+j read samples which bracket the original read sample SAM(k) such that:I(k)=a.sub.k-i SAM(k-i)+ . . . +a.sub.k SAM(k)+ . . . +a.sub.

Abstract: A display screen for improving the angle of view from which displayed images can be perceived accurately. An illumination device produces light which is collimated along a plane YOZ orthogonal to the plane XOZ in which the screen has its best characteristics in terms of contrast and/or levels of gray. The collimated illumination device is on the front face of a cell. A device for distributing the light (by diffraction or scattering) in the plane YOZ is placed at the output of the cell. One or more compensation films can be placed at the output of the cell to increase the angle of view in the plane XOZ. This device may be used in avionics and the display of video images.

Abstract: The disclosure is an automatic programming method for a tuner of a television and/or video recorder that makes use of data received by cable or terrestrial or satellite radio, and a device implementing this method. The method involves the transmission of a set of channel tables, each corresponding to a broadcasting station, using the CEEFAX standard. The television or video recorder memorizes the table corresponding to the postal ZIP code previously input by the user, then automatically programs the tuner. The invention is applicable for all types of television standards (PAL, PAL+, SECAM, NTSC, D2MAC, HDMAC, digital standards, etc.) and to all types of signal formats transmitted with the video signals.

Abstract: A method for the making of a magnetic recording/reading head comprises the following steps:the making of magnetic excitation wires on or in a first face of a substrate having this first face and a second face opposite the first face;the making, on the first or second face of the substrate, of at least two magnetic poles separated by a gap;the drilling of holes through the substrate from the face opposite the one bearing the magnetic poles, each ending in such a way that there is magnetic coupling between the bottom of the hole and the pole;the deposition of a layer of material with high magnetic permeability in the holes and in the zones of the substrate located between the holes. Applications: the making of magnetic recording/reading heads for video-tape recorders, computer peripherals and professional recording machines.

Abstract: Magnetic write/read heads for writing/reading information on a recording medium passing in front of the heads include several groups of magnetic write/read heads, each group of magnetic write/read heads including several pairs of poles. Each pair of poles is separated by a head gap of an integer multiple of an elementary track width b and forms several head gaps E0 to E7. The head gaps (for example El) have a first width such that they can write across a first width of the recording medium, and the second head gaps (for example E2) have a second width less than the first width and are arranged in such a way that the second head gaps write/read an area of the recording medium superimposed on the area of the recording medium write/read by the first head gaps. The magnetic write/read heads are suitable for applications where multitrack write/read heads are required.