Thomson-csf

Thomson Tubes Electroniques

Michel Specty

Michel Gay

Serge Salavin

Jacques Deschamps

Louis Delgrange

Philippe Zorzan

Francoise Vialettes

Bruno Rimaud

In a method for adjusting the overall luminosity of at least a part of a matrix screen, each row of the part is processed several times non-periodically to display half-tones. Each processing consists of a semi-selective operation followed by a selective operation. A delay is planned between the selective operation and the semi-selective operation, this delay being proportional to a weighting factor that is adjustable as a function of the desired overall luminosity and proportional to the time interval between the beginning of the treatment in progress and the beginning of the next treatment.

Method for adjusting the overall luminosity of a bistable matrix screen displaying half-tones

Disclosed is a method for the control of display screens that can be applied to internal memory type screens, notably plasma display panels for which it increases the dynamic range of the adjusting of the luminosity. This method consists in controlling the cells (C1 to C16) of the screen by means of addressing commands, each one of which comprises a selective command and a semi-selective command. According to one characteristic, for the addressing of one and the same line (L1 to L4) of cells (C1 to C16), the method consists in separating the selective command (CI) from the semi-selective command (CE) by an adjustable interval of time (PL1 to PL4).

Method for adjusting the luminosity of display screens

Disclosed is a method for the row-by-row control of the pixels of a plasma panel. This method is applicable in the case where a pixel is defined at the intersection of a column electrode with a pair of sustaining electrodes. The method disclosed makes it possible to obtain, notably, a reduced cycle time with a small number of voltage levels applied to the different electrodes. To this effect, according to one characteristic of the invention, the method consists in the erasure of the pixels of a row solely by erasing discharges generated between the electrodes of the corresponding electrode pair.

Method for the row-by-row control of a coplanar sustaining AC type of

A coplanar sustaining plasma panel, and particularly an electrode arrangement make is possible to better contain the sustaining discharges in a predetermined zone. Plasma panel (10) of the invention comprises addressing electrodes (X1 to X3) crossed with sustaining electrodes arranged by pair (p1, p2), each sustaining electrode pair being formed of an addressing-sustaining electrode (Y1, Y2) and a sustaining-only electrode (E1, E2). A pixel (PX1 to PX6) consists approximately at each crossing of an addressing electrode (X1, X2, X3) with a sustaining electrode pair (p1, p2). At least one of two electrodes (Y1, E1) of same pair (p1) comprises, at the level of each pixel (PX1 to PX6), a projecting surface (SB1 to SB3, SC1, SC3) oriented toward the other electrode. According to a characteristic of the invention, projecting surfaces (SB1 to SB3, SC1 to SC3) are arranged so that between two consecutive pixels (PX1 to PX6) of same pair (p1, p2), of the two closest projecting surfaces, one belongs to an addressing-sustaining electrode (Y1, Y2) and the other to a sustaining-only electrode (E1, E2).

Plasma panels in delimited discharge zones

Disclosed is a method for the control of the pixels of a plasma panel by selective addressing and semi-selective addressing. The disclosed method can be applied to cases where a pixel is defined at the intersection of a column electrode with a pair of sustaining electrodes. The disclosed method can be used, notably, to obtain a reduced picture cycle time. To this effect, according to one characteristic of the disclosed method, certain pixels are controlled simultaneously by semi-selective addressing while other pixels are controlled by selective addressing.

Very fast method of control by semi-selective and selective addressing

The invention pertains to an alternating type of plasma panel. Each pixel is defined by three parallel and coplanar electrodes and by an electrode which is perpendicular to the other three electrodes and is separated from the other three electrodes by at least one dielectric layer. Two of the three parallel electrodes are connected to circuits giving the refresh signals to each pixel during operation. The electrode perpendicular to the other three and that electrode, of the other three parallel electrodes, which is not connected to a refresh circuit, are connected to circuits that give addressing signals to each pixel during operation. The electrodes that are connected to the refresh circuits constitute two arrays of electrodes connected to two refresh circuits.

Plasma panel with four electrodes per pixel and method for the control

A control circuit is provided for an alternating type plasma display panel, comprising integrated circuits which are used for the first and second electrode arrays of the panel. In the first array, the integrated circuits participate in producing selective signals and transmit the reference voltage of the sustaining signals. In the second array, the integrated circuits participate in producing selective signals, and transmit the square wave voltage of the sustaining signals and their reference voltage is floating, that is to say that it follows the sustaining signals and, during production of the selective signals, it follows the lowest potential that is possible to apply to the electrodes. The integrated circuits are provided with logic circuits which receive a signal indicating whether the integrated circuit is used with the first or with the second electrode arrays, so that in the case of use with the first array the active electrodes are brought to the high level with respect to the non active electrode and in the case of use with the second array the non active electrodes are brought to the high level with respect to the active electrodes.

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Echirolles, France

Michel Specty