EP0734043A1 - Double-gated flat display screen - Google Patents

Double-gated flat display screen Download PDF

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Publication number
EP0734043A1
EP0734043A1 EP96410030A EP96410030A EP0734043A1 EP 0734043 A1 EP0734043 A1 EP 0734043A1 EP 96410030 A EP96410030 A EP 96410030A EP 96410030 A EP96410030 A EP 96410030A EP 0734043 A1 EP0734043 A1 EP 0734043A1
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EP
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Prior art keywords
grid
addressed
cathode
comb
rows
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EP96410030A
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German (de)
French (fr)
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EP0734043B1 (en
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Bernard Bancal
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Pixtech SA
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Pixtech SA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J29/00—Details of cathode-ray tubes or of electron-beam tubes of the types covered by group H01J31/00
    • H01J29/46—Arrangements of electrodes and associated parts for generating or controlling the ray or beam, e.g. electron-optical arrangement
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/10—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes
    • H01J31/12—Image or pattern display tubes, i.e. having electrical input and optical output; Flying-spot tubes for scanning purposes with luminescent screen
    • H01J31/123—Flat display tubes
    • H01J31/125—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection
    • H01J31/127—Flat display tubes provided with control means permitting the electron beam to reach selected parts of the screen, e.g. digital selection using large area or array sources, i.e. essentially a source for each pixel group

Definitions

  • the present invention relates to the production of a flat display screen. It applies more particularly to a flat screen of the type comprising an electron bombardment cathode of an anode carrying phosphor elements. It is, for example, a fluorescent screen in which an electronic emission is obtained by extraction of electrons from microtips or from a thin film, for example a carbon-diamond film.
  • FIG. 1 represents the functional structure of a flat screen with microtips of the type to which the invention relates.
  • Such a microtip screen essentially consists of a cathode 1 with microtips 2 and a grid 3 provided with holes 4 corresponding to the locations of the microtips 2.
  • the cathode 1 is placed opposite a cathodoluminescent anode 5 including a substrate of glass 6 constitutes the screen surface.
  • the cathode 1 is organized in columns and consists, on a substrate 10 for example of glass, of cathode conductors organized in meshes from a conductive layer.
  • the microtips 2 are produced on a resistive layer 11 deposited on the cathode conductors and are arranged inside the meshes defined by the cathode conductors.
  • FIG. 1 partially represents the interior of a mesh, the cathode conductors do not appear in this figure.
  • the cathode 1 is associated with the grid 3 which is it organized in rows, an insulating layer (not shown) being interposed between the cathode conductors and the grid 3. The intersection of a row of the grid 3 and a column of cathode 1 defines a pixel.
  • This device uses the electric field created between the cathode 1 and the grid 3 so that electrons are extracted from the microtips 2 towards phosphor elements 7 of the anode 5 by crossing an empty space between electrodes 12.
  • the anode 5 is provided with alternating bands of phosphor elements 7, each corresponding to a color (Blue, Red, Green). The strips are separated from each other by an insulator 8.
  • the phosphor elements 7 are deposited on electrodes 9, consisting of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO) .
  • ITO indium tin oxide
  • the sets of blue, red and green bands are alternately polarized with respect to the cathode 1, so that the electrons extracted from the microtips 2 of a pixel of the cathode / grid are alternately directed towards the phosphor elements 7 opposite each other colours.
  • the display of an image is carried out by suitably polarizing the anode, the cathode and the grid by means of control electronics (not shown).
  • the rows of the grid 3 are sequentially polarized at a potential of the order of 80 volts while the strips of phosphor elements (for example 7g in Figure 1) to be excited are biased under a voltage of the order of 400 volts, the other bands (for example 7r and 7b in Figure 1) being at zero potential.
  • the columns of cathode 1, the potential of which represents for each row of grid 3 the brightness of the pixel defined by the intersection of the column of cathode and of the row of grid in the color considered, are brought to potentials respective between a maximum emission potential and a non-emission potential (for example, 0 and 30 volts respectively).
  • the choice of the values of the polarization potentials is linked to the characteristics of the phosphor elements 7 and of the microtips 2. Conventionally, below a potential difference of 50 volts between the cathode 1 and the grid 3, there is no electronic emission and the maximum emission used corresponds to a potential difference of 80 volts.
  • a drawback of conventional screens is that the individual addressing of the rows of the grid 3 requires one connection per row to the control electronics.
  • the control electronics must therefore include one output stage per grid row, which increases the cost.
  • the output stages associated with the grid must, in addition, withstand voltages of up to 100 volts, which makes them relatively expensive.
  • the silicon surface being proportional to the square of the breakdown voltage, such output stages, produced in the form of an integrated circuit, require relatively large surfaces.
  • connection per row of grids prohibits the production of high definition screens and small dimensions because of the minimum pitch which it is necessary to maintain between two connections of two neighboring rows. Indeed, the connection for steps less than about 200 ⁇ m is very difficult to achieve.
  • the present invention aims to overcome these drawbacks by proposing a flat display screen in which the number of output stages and connections intended for addressing the grid is less than the number of lines on the screen.
  • the invention also aims to allow the realization of a high definition screen and small dimensions.
  • the invention further aims to propose the production of such a flat display screen which does not require modification of the cathode and the anode, nor of the elements of the control electronics associated with the cathode or the anode.
  • the present invention provides a flat display screen of the type comprising a cathode organized in columns of electronic bombardment of an anode provided with phosphor elements, and comprising a first grid organized in rows capable of being addressed individually and a second grid consisting of at least two combs of alternating tracks parallel to said rows of said first grid, the same row of said first grid being associated with a track of each comb and the intersection of each track with a column of the cathode defining one pixel of the screen.
  • the display of an image is effected, in an interlaced manner, by sequentially addressing said rows of the first grid for the duration of an alternative addressing of said combs of the second grid.
  • the columns of the cathode are addressed simultaneously to each row of the first grid, their potential being a function of the desired brightness for the pixel defined by their intersection with the track of the addressed comb of the second. grid which is plumb with the current row.
  • the polarization potentials of said combs are chosen so that the tracks of an addressed comb focus, towards the anode, the electrons emitted by the columns of the cathode to plumb with the track of said focusing comb associated with an addressed row, and so that the tracks of a comb which is not addressed collect the electrons emitted by the columns of the cathode in line with the track of said collecting comb associated with the addressed row.
  • the potential of a focusing comb is greater than the potential of the rows of the first grid which are not addressed, the potential of a collecting comb being less than the potential of the rows of the first grid. that are not addressed.
  • the pitch of the rows of the first grid is dimensioned as a function of the minimum pitch to be respected between the individual connections of these rows to a control electronics, the number of combs of the second grid being chosen according to the desired definition for the screen.
  • said grids are applied to a color screen whose anode is provided with three sets of alternating strips of phosphor elements each corresponding to a color.
  • said grids are applied to a monochrome screen whose anode consists of phosphor elements of a single type.
  • the main idea of the present invention is to associate with the screen cathode two superimposed grids and addressed differently.
  • FIG. 2 illustrates, by a top view of a cathode plate / grid of a microtip screen, an embodiment of the present invention.
  • a first grid 20 is similar to the grid (3, FIG. 1) with which conventional screens are provided, except that the width of its rows 21 corresponds to at least two pixels of the screen.
  • the rows 21 of this first grid 20 are addressed individually and are therefore connected individually by one of their ends to a control electronics (not shown).
  • a second grid 23 is attached to this first grid.
  • This second grid 23 consists of at least two combs 24 and 25 of alternating conductive tracks, 26 and 27 respectively.
  • One track of each comb is plumb with a row 21 of the first grid 20 so that each row 21 is covered with two tracks 26 and 27 of the second grid 23.
  • all the tracks 26, respectively 27, are capable of being addressed simultaneously by being connected together to the control electronics.
  • a pixel of the screen is here defined by the intersection of a column, or a conductor 28, of the cathode 1 with a track 26 or 27 of the second grid 23.
  • the rows 21 of the first grid 20 and the tracks 26 and 27 of the second grid 23 are provided with holes 4 at the location of the microtips arranged on conductors 28 of the cathode 1 organized in columns.
  • holes 4 For the sake of clarity, only one hole 4 per pixel has been represented in FIG. 2 whereas in practice the number of holes 4 corresponds to the number of microtips and is several thousand per pixel. Likewise, the mesh of the cathode conductors 28 has not been shown.
  • Each grid is, for example, made up of a layer of niobium etched according to the appropriate pattern.
  • An insulating layer, etched directly above each microtip, is interposed between the cathode 1 and the first grid 20 and, between the first grid 20 and the second grid 23.
  • each comb 24 or 25 of the second grid 23 is to allow, alternately, depending on whether or not it is addressed, the focusing of the electrons emitted by the microtips which are plumb with the row 21 addressed from the first grid 20 and of track 26, respectively 27, addressed, or the collection of electrons emitted by the microtips which are vertically aligned with row 21 addressed and track 27, respectively 26, not addressed.
  • the display of an image takes place during a frame time (for example 20 ms) by suitably polarizing the anode, the cathode and the grids by means of the control electronics.
  • a frame time for example 20 ms
  • the bands of phosphor elements 7 of the anode 5 are sequentially polarized, during a frame, by sets of bands of the same color, that is to say for a duration of sub-frame corresponding to one third of the frame time (for example 6.6 ms).
  • the display is carried out line by line but in an interlaced manner, during each sub-frame.
  • the other comb (for example 25) of the second grid 23 is addressed and again, sequentially, all the rows 21 of the first grid 20 are addressed during a "row time" during which each column 28 of the cathode 1 is brought to a potential which is a function of the brightness of the pixel to be displayed along the track (for example 27) associated with the current row 21 in the color considered.
  • a "line time” (for example 13.7 ⁇ s) corresponds to the duration of a sub-frame divided by the number of rows 21 of the first grid 20 multiplied by the number of combs of the second grid 23.
  • FIG. 3 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 3 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 2 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 2 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 2 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 2 shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention.
  • FIG. 2 shows, partially and in exploded perspective, a conductor 28 of the ca
  • the potential V G of a row 21 of the first grid 20 which is addressed is, as for conventional screens, for example of 80 volts while it is 0 volts for the rows 21 which are not addressed.
  • the potential V K of the columns 28 of the cathode is, as for conventional screens, for example between 0 and 30 volts depending on the desired brightness for the pixel considered.
  • the potential V f of the tracks of an addressed comb is greater than the potential of the rows 21 which are not addressed. If the first grid 20 is polarized between 0 and 80 volts, we will choose, for example, a potential V f of the order of 5 volts for the focusing comb.
  • the potential V c thereof is lower than the potential of the rows 21 which are not addressed. If the first grid 20 is polarized between 0 and 80 volts, we will choose, for example, a potential V c of the order of -5 volts for the collector comb.
  • the number of combs of the second grid 23 is chosen according to the number of output stages, or connections, desired for the grids and / or the desired definition for the screen in the direction of the columns 28 of the cathode 1 and / or the form in which the luminance setpoints arrive in the control electronics.
  • the second grid 23 consists of three combs with one comb per color.
  • the second grid 23 has a greater number of combs. For example, it is conceivable that the scanned image is saved in a frame memory whose content can easily be read in jumps of eight. It is then advantageously possible to provide eight combs for the second grid 23 and thus make it possible to view eight successive interlaced subframes.
  • An advantage of the present invention is that for a screen of a given number N of lines, the number of output stages of the control electronics associated with the gates, therefore of connections of the gates to the control electronics, is of M + N / M, where M represents the number of combs of the second grid 23. In the example shown in FIGS. 2 and 3, the number of output stages and connections necessary for the grids is almost halved .
  • a screen, according to the invention, of 288 rows by 360 columns, the second grid of which has two combs can be produced by using 146 (144 for rows 21 and 2 for combs 24 and 25) output stages and connections associated with the gates.
  • Another advantage of the present invention is that it makes it possible to reduce the number of output stages and connections without modifying the structure of the cathode and the anode of the screen, nor of the associated control electronics. at the cathode and at the anode.
  • Another advantage of the present invention is that it makes it possible to produce screens of high definition and of small dimensions, where at least one of the dimensions of a pixel is less than the minimum pitch between the connections of the grid rows.
  • the implementation of the invention makes it possible to increase the definition of the screen, at least in the direction perpendicular to the rows of the grid, by a factor of M corresponding to the number of combs of the second grid 23. In the example shown in Figures 2 and 3, this amounts to doubling the definition of the screen in that direction.
  • the connections of the cathode columns and / or the first grid must be allow.
  • a square screen of 1024 pixels side can, according to the invention, be produced on a surface of 10 cm side.
  • the pixel pitch is then of the order of 0.1 mm.
  • the pitch of rows 21 of the first grid is 0.2 mm, which is compatible with the minimum pitch of conventional connections.
  • Each track 26 or 27 of the second grid 23 has, for example, a width of the order of 75 ⁇ m and two neighboring tracks are spaced about 25 ⁇ m apart.
  • the invention also applies to a fluorescent screen, the cathode of which is formed from a film, for example of carbon-diamond, of electronic emission.

Abstract

The screen has cathodes (1) organised in columns (28) to bombard a phosphor anode. The rows (21) of a first grid (20) are addressed sequentially during a period when the combs (24,25) of a second grid (23) are addressed alternately to form an interlaced image. The cathode columns are addressed simultaneously with each row at a potential to determine the brightness for a pixel defined by the comb addressed within the current row. The bias potential on the combs is chosen so that the electrons emitted by the cathode directly below the comb tracks (26,27) are such that the unaddressed tracks collect the electrons. The focusing potential for a track is greater than that of the unaddressed rows of the first grid while that of the collector is less. Three such assemblies are used to provide a colour display.

Description

La présente invention concerne la réalisation d'un écran plat de visualisation. Elle s'applique plus particulièrement à un écran plat du type comportant une cathode de bombardement électronique d'une anode portant des éléments luminophores. Il s'agit, par exemple, d'un écran fluorescent dans lequel une émission électronique est obtenue par extraction d'électrons de micropointes ou d'un film mince, par exemple un film de carbone-diamant.The present invention relates to the production of a flat display screen. It applies more particularly to a flat screen of the type comprising an electron bombardment cathode of an anode carrying phosphor elements. It is, for example, a fluorescent screen in which an electronic emission is obtained by extraction of electrons from microtips or from a thin film, for example a carbon-diamond film.

La figure 1 représente la structure fonctionnelle d'un écran plat à micropointes du type auquel se rapporte l'invention.FIG. 1 represents the functional structure of a flat screen with microtips of the type to which the invention relates.

Un tel écran à micropointes est essentiellement constitué d'une cathode 1 à micropointes 2 et d'une grille 3 pourvue de trous 4 correspondant aux emplacements des micropointes 2. La cathode 1 est placée en regard d'une anode cathodoluminescente 5 dont un substrat de verre 6 constitue la surface d'écran.Such a microtip screen essentially consists of a cathode 1 with microtips 2 and a grid 3 provided with holes 4 corresponding to the locations of the microtips 2. The cathode 1 is placed opposite a cathodoluminescent anode 5 including a substrate of glass 6 constitutes the screen surface.

Le principe de fonctionnement et le détail de la constitution d'un tel écran à micropointes sont décrits dans le brevet américain numéro 4 940 916 du Commissariat à l'Energie Atomique.The operating principle and the detail of the constitution of such a microtip screen are described in American patent number 4 940 916 of the French Atomic Energy Commission.

La cathode 1 est organisée en colonnes et est constituée, sur un substrat 10 par exemple en verre, de conducteurs de cathode organisés en mailles à partir d'une couche conductrice. Les micropointes 2 sont réalisées sur une couche résistive 11 déposée sur les conducteurs de cathode et sont disposées à l'intérieur des mailles définies par les conducteurs de cathode. La figure 1 représentant partiellement l'intérieur d'une maille, les conducteurs de cathode n'apparaissent pas sur cette figure. La cathode 1 est associée à la grille 3 qui est elle organisée en rangées, une couche isolante (non représentée) étant interposée entre les conducteurs de cathode et la grille 3. L'intersection, d'une rangée de la grille 3 et d'une colonne de la cathode 1, définit un pixel.The cathode 1 is organized in columns and consists, on a substrate 10 for example of glass, of cathode conductors organized in meshes from a conductive layer. The microtips 2 are produced on a resistive layer 11 deposited on the cathode conductors and are arranged inside the meshes defined by the cathode conductors. FIG. 1 partially represents the interior of a mesh, the cathode conductors do not appear in this figure. The cathode 1 is associated with the grid 3 which is it organized in rows, an insulating layer (not shown) being interposed between the cathode conductors and the grid 3. The intersection of a row of the grid 3 and a column of cathode 1 defines a pixel.

Ce dispositif utilise le champ électrique créé entre la cathode 1 et la grille 3 pour que des électrons soient extraits des micropointes 2 vers des éléments luminophores 7 de l'anode 5 en traversant un espace vide inter-électrodes 12.This device uses the electric field created between the cathode 1 and the grid 3 so that electrons are extracted from the microtips 2 towards phosphor elements 7 of the anode 5 by crossing an empty space between electrodes 12.

Pour un écran couleur, l'anode 5 est pourvue de bandes alternées d'éléments luminophores 7, correspondant chacune à une couleur (Bleu, Rouge, Vert). Les bandes sont séparées les unes des autres par un isolant 8. Les éléments luminophores 7 sont déposés sur des électrodes 9, constituées de bandes correspondantes d'une couche conductrice transparente telle que de l'oxyde d'indium et d'étain (ITO). Les ensembles de bandes bleues, rouges, vertes sont alternativement polarisés par rapport à la cathode 1, pour que les électrons extraits des micropointes 2 d'un pixel de la cathode/grille soient alternativement dirigés vers les éléments luminophores 7 en vis à vis de chacune des couleurs.For a color screen, the anode 5 is provided with alternating bands of phosphor elements 7, each corresponding to a color (Blue, Red, Green). The strips are separated from each other by an insulator 8. The phosphor elements 7 are deposited on electrodes 9, consisting of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO) . The sets of blue, red and green bands are alternately polarized with respect to the cathode 1, so that the electrons extracted from the microtips 2 of a pixel of the cathode / grid are alternately directed towards the phosphor elements 7 opposite each other colours.

L'affichage d'une image s'effectue en polarisant convenablement l'anode, la cathode et la grille au moyen d'une électronique de commande (non représentée).The display of an image is carried out by suitably polarizing the anode, the cathode and the grid by means of control electronics (not shown).

Généralement, les rangées de la grille 3 sont séquentiellement polarisées à un potentiel de l'ordre de 80 volts tandis que les bandes d'éléments luminophores (par exemple 7g en figure 1) devant être excitées sont polarisées sous une tension de l'ordre de 400 volts, les autres bandes (par exemple 7r et 7b en figure 1) étant à un potentiel nul. Les colonnes de la cathode 1, dont le potentiel représente pour chaque rangée de la grille 3 la brillance du pixel défini par l'intersection de la colonne de la cathode et de la rangée de la grille dans la couleur considérée, sont portées à des potentiels respectifs compris entre un potentiel d'émission maximale et un potentiel d'absence d'émission (par exemple, respectivement 0 et 30 volts).Generally, the rows of the grid 3 are sequentially polarized at a potential of the order of 80 volts while the strips of phosphor elements (for example 7g in Figure 1) to be excited are biased under a voltage of the order of 400 volts, the other bands (for example 7r and 7b in Figure 1) being at zero potential. The columns of cathode 1, the potential of which represents for each row of grid 3 the brightness of the pixel defined by the intersection of the column of cathode and of the row of grid in the color considered, are brought to potentials respective between a maximum emission potential and a non-emission potential (for example, 0 and 30 volts respectively).

Le choix des valeurs des potentiels de polarisation est lié aux caractéristiques des éléments luminophores 7 et des micropointes 2. Classiquement, en dessous d'une différence de potentiel de 50 volts entre la cathode 1 et la grille 3, il n'y a pas d'émission électronique et l'émission maximale utilisée correspond à une différence de potentiel de 80 volts.The choice of the values of the polarization potentials is linked to the characteristics of the phosphor elements 7 and of the microtips 2. Conventionally, below a potential difference of 50 volts between the cathode 1 and the grid 3, there is no electronic emission and the maximum emission used corresponds to a potential difference of 80 volts.

Un inconvénient des écrans classiques est que l'adressage individuel des rangées de la grille 3 nécessite une connexion par rangée vers l'électronique de commande. L'électronique de commande doit donc comporter un étage de sortie par rangée de grille ce qui en augmente le coût. Les étages de sortie associés à la grille doivent, de plus, supporter des tensions pouvant aller jusqu'à 100 volts ce qui les rend relativement chers. En outre, la surface de silicium étant proportionnelle au carré de la tension de claquage, de tels étages de sortie, réalisés sous la forme de circuit intégré, nécessitent des surfaces relativement importantes.A drawback of conventional screens is that the individual addressing of the rows of the grid 3 requires one connection per row to the control electronics. The control electronics must therefore include one output stage per grid row, which increases the cost. The output stages associated with the grid must, in addition, withstand voltages of up to 100 volts, which makes them relatively expensive. In addition, the silicon surface being proportional to the square of the breakdown voltage, such output stages, produced in the form of an integrated circuit, require relatively large surfaces.

Un autre inconvénient est que le besoin d'une connexion par rangée de grille interdit la réalisation d'écran de haute définition et de petites dimensions en raison du pas minimal qu'il est nécessaire de maintenir entre deux connexions de deux rangées voisines. En effet, la connectique pour des pas inférieurs à environ 200 µm est très difficile à réaliser.Another disadvantage is that the need for a connection per row of grids prohibits the production of high definition screens and small dimensions because of the minimum pitch which it is necessary to maintain between two connections of two neighboring rows. Indeed, the connection for steps less than about 200 µm is very difficult to achieve.

La présente invention vise à pallier ces inconvénients en proposant un écran plat de visualisation dans lequel le nombre d'étages de sortie et de connexions destinés à l'adressage de la grille est inférieur au nombre de lignes de l'écran.The present invention aims to overcome these drawbacks by proposing a flat display screen in which the number of output stages and connections intended for addressing the grid is less than the number of lines on the screen.

L'invention vise également à permettre la réalisation d'un écran de haute définition et de petites dimensions.The invention also aims to allow the realization of a high definition screen and small dimensions.

L'invention vise en outre à proposer la réalisation d'un tel écran plat de visualisation qui ne nécessite pas de modification de la cathode et de l'anode, ni des éléments de l'électronique de commande associés à la cathode ou à l'anode.The invention further aims to propose the production of such a flat display screen which does not require modification of the cathode and the anode, nor of the elements of the control electronics associated with the cathode or the anode.

Pour atteindre ces objets, la présente invention prévoit un écran plat de visualisation du type comportant une cathode organisée en colonnes de bombardement électronique d'une anode pourvue d'éléments luminophores, et comportant une première grille organisée en rangées susceptibles d'être adressées individuellement et une seconde grille constituée d'au moins deux peignes de pistes alternées parallèles auxdites rangées de ladite première grille, une même rangée de ladite première grille étant associée à une piste de chaque peigne et l'intersection de chaque piste avec une colonne de la cathode définissant un pixel de l'écran.To achieve these objects, the present invention provides a flat display screen of the type comprising a cathode organized in columns of electronic bombardment of an anode provided with phosphor elements, and comprising a first grid organized in rows capable of being addressed individually and a second grid consisting of at least two combs of alternating tracks parallel to said rows of said first grid, the same row of said first grid being associated with a track of each comb and the intersection of each track with a column of the cathode defining one pixel of the screen.

Selon un mode de réalisation de la présente invention, l'affichage d'une image s'effectue, de manière entrelacée, en adressant séquentiellement lesdites rangées de la première grille pendant la durée d'un adressage alternatif desdits peignes de la seconde grille.According to an embodiment of the present invention, the display of an image is effected, in an interlaced manner, by sequentially addressing said rows of the first grid for the duration of an alternative addressing of said combs of the second grid.

Selon un mode de réalisation de la présente invention, les colonnes de la cathode sont adressées simultanément à chaque rangée de la première grille, leur potentiel étant fonction de la brillance souhaitée pour le pixel défini par leur intersection avec la piste du peigne adressé de la seconde grille qui se trouve à l'aplomb de la rangée courante.According to an embodiment of the present invention, the columns of the cathode are addressed simultaneously to each row of the first grid, their potential being a function of the desired brightness for the pixel defined by their intersection with the track of the addressed comb of the second. grid which is plumb with the current row.

Selon un mode de réalisation de la présente invention, les potentiels de polarisation desdits peignes sont choisis pour que les pistes d'un peigne adressé focalisent, vers l'anode, les électrons émis par les colonnes de la cathode à l'aplomb de la piste dudit peigne focalisateur associée à une rangée adressée, et pour que les pistes d'un peigne qui n'est pas adressé collectent les électrons émis par les colonnes de la cathode à l'aplomb de la piste dudit peigne collecteur associée à la rangée adressée.According to one embodiment of the present invention, the polarization potentials of said combs are chosen so that the tracks of an addressed comb focus, towards the anode, the electrons emitted by the columns of the cathode to plumb with the track of said focusing comb associated with an addressed row, and so that the tracks of a comb which is not addressed collect the electrons emitted by the columns of the cathode in line with the track of said collecting comb associated with the addressed row.

Selon un mode de réalisation de la présente invention, le potentiel d'un peigne focalisateur est supérieur au potentiel des rangées de la première grille qui ne sont pas adressées, le potentiel d'un peigne collecteur étant inférieur au potentiel des rangées de la première grille qui ne sont pas adressées.According to one embodiment of the present invention, the potential of a focusing comb is greater than the potential of the rows of the first grid which are not addressed, the potential of a collecting comb being less than the potential of the rows of the first grid. that are not addressed.

Selon un mode de réalisation de la présente invention, le pas des rangées de la première grille est dimensionné en fonction du pas minimal devant être respecté entre les connexions individuelles de ces rangées vers une électronique de commande, le nombre de peignes de la seconde grille étant choisi en fonction de la définition souhaitée pour l'écran.According to an embodiment of the present invention, the pitch of the rows of the first grid is dimensioned as a function of the minimum pitch to be respected between the individual connections of these rows to a control electronics, the number of combs of the second grid being chosen according to the desired definition for the screen.

Selon un mode de réalisation de la présente invention, lesdites grilles sont appliquées à un écran couleur dont l'anode est pourvue de trois ensembles de bandes alternées d'éléments luminophores correspondant chacun à une couleur.According to an embodiment of the present invention, said grids are applied to a color screen whose anode is provided with three sets of alternating strips of phosphor elements each corresponding to a color.

Selon un mode de réalisation de la présente invention, lesdites grilles sont appliquées à un écran monochrome dont l'anode est constituée d'éléments luminophores d'un seul type.According to an embodiment of the present invention, said grids are applied to a monochrome screen whose anode consists of phosphor elements of a single type.

Ces objets, caractéristiques et avantages, ainsi que d'autres de la présente invention seront exposés en détail dans la description suivante de modes de réalisation particuliers faite à titre non limitatif en relation avec les figures jointes parmi lesquelles :

  • la figure 1 décrite précédemment est destinée à exposer l'état de la technique et le problème posé ;
  • la figure 2 représente une vue de dessus d'une plaque de cathode/grille d'un écran plat selon un mode de réalisation de la présente invention ; et
  • la figure 3 est une vue partielle en perspective éclatée de la cathode/grille représentée à la figure 2.
These objects, characteristics and advantages, as well as others of the present invention will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:
  • Figure 1 described above is intended to expose the state of the art and the problem posed;
  • FIG. 2 represents a top view of a cathode plate / grid of a flat screen according to an embodiment of the present invention; and
  • FIG. 3 is a partial exploded perspective view of the cathode / grid shown in FIG. 2.

Pour des raisons de clarté, les représentations des figures ne sont pas à l'échelle et les mêmes éléments ont été désignés par les mêmes références aux différentes figures.For reasons of clarity, the representations of the figures are not to scale and the same elements have been designated by the same references in the different figures.

L'idée mère de la présente invention est d'associer à la cathode de l'écran deux grilles superposées et adressées différemment.The main idea of the present invention is to associate with the screen cathode two superimposed grids and addressed differently.

La figure 2 illustre, par une vue de dessus d'une plaque de cathode/grille d'un écran à micropointes, un mode de réalisation de la présente invention.FIG. 2 illustrates, by a top view of a cathode plate / grid of a microtip screen, an embodiment of the present invention.

Une première grille 20 est similaire à la grille (3, figure 1) dont sont pourvus les écrans classiques à la différence près que la largeur de ses rangées 21 correspond à au moins deux pixels de l'écran. Les rangées 21 de cette première grille 20 sont adressées individuellement et sont donc reliées individuellement par une de leurs extrémités à une électronique de commande (non représentée).A first grid 20 is similar to the grid (3, FIG. 1) with which conventional screens are provided, except that the width of its rows 21 corresponds to at least two pixels of the screen. The rows 21 of this first grid 20 are addressed individually and are therefore connected individually by one of their ends to a control electronics (not shown).

Une seconde grille 23 est rapportée sur cette première grille. Cette seconde grille 23 est constituée d'au moins deux peignes 24 et 25 de pistes conductrices, respectivement 26 et 27, alternées. Une piste de chaque peigne se trouve à l'aplomb d'une rangée 21 de la première grille 20 de sorte que chaque rangée 21 est recouverte de deux pistes 26 et 27 de la seconde grille 23. De par leur organisation en peigne, toutes les pistes 26, respectivement 27, sont susceptibles d'être adressées simultanément en étant reliées ensemble à l'électronique de commande. Un pixel de l'écran est ici défini par l'intersection d'une colonne, ou d'un conducteur 28, de la cathode 1 avec une piste 26 ou 27 de la seconde grille 23.A second grid 23 is attached to this first grid. This second grid 23 consists of at least two combs 24 and 25 of alternating conductive tracks, 26 and 27 respectively. One track of each comb is plumb with a row 21 of the first grid 20 so that each row 21 is covered with two tracks 26 and 27 of the second grid 23. By their organization in comb, all the tracks 26, respectively 27, are capable of being addressed simultaneously by being connected together to the control electronics. A pixel of the screen is here defined by the intersection of a column, or a conductor 28, of the cathode 1 with a track 26 or 27 of the second grid 23.

Les rangées 21 de la première grille 20 et les pistes 26 et 27 de la seconde grille 23 sont pourvues de trous 4 à l'emplacement des micropointes disposées sur des conducteurs 28 de la cathode 1 organisés en colonnes. Pour des raisons de clarté, seul un trou 4 par pixel a été représenté à la figure 2 alors qu'en pratique le nombre de trous 4 correspond au nombre de micropointes et est de plusieurs milliers par pixel. De même, le maillage des conducteurs de cathode 28 n'a pas été représenté.The rows 21 of the first grid 20 and the tracks 26 and 27 of the second grid 23 are provided with holes 4 at the location of the microtips arranged on conductors 28 of the cathode 1 organized in columns. For the sake of clarity, only one hole 4 per pixel has been represented in FIG. 2 whereas in practice the number of holes 4 corresponds to the number of microtips and is several thousand per pixel. Likewise, the mesh of the cathode conductors 28 has not been shown.

La réalisation pratique des grilles 20 et 23 s'effectue d'une manière similaire à la réalisation de la grille d'un écran classique. Chaque grille est, par exemple, constituée d'une couche de niobium gravée selon le motif approprié. Une couche d'isolement, gravée à l'aplomb de chaque micropointe, est interposée entre la cathode 1 et la première grille 20 et, entre la première grille 20 et la seconde grille 23.The practical production of the grids 20 and 23 is carried out in a similar manner to the production of the grid of a conventional screen. Each grid is, for example, made up of a layer of niobium etched according to the appropriate pattern. An insulating layer, etched directly above each microtip, is interposed between the cathode 1 and the first grid 20 and, between the first grid 20 and the second grid 23.

Le rôle de chaque peigne 24 ou 25 de la seconde grille 23 est de permettre, alternativement, selon qu'il est ou non adressé, la focalisation des électrons émis par les micropointes qui sont à l'aplomb de la rangée 21 adressée de la première grille 20 et de la piste 26, respectivement 27, adressée, ou la collecte des électrons émis par les micropointes qui sont à l'aplomb de la rangée 21 adressée et de la piste 27, respectivement 26, non adressée.The role of each comb 24 or 25 of the second grid 23 is to allow, alternately, depending on whether or not it is addressed, the focusing of the electrons emitted by the microtips which are plumb with the row 21 addressed from the first grid 20 and of track 26, respectively 27, addressed, or the collection of electrons emitted by the microtips which are vertically aligned with row 21 addressed and track 27, respectively 26, not addressed.

L'affichage d'une image s'effectue pendant un temps de trame (par exemple 20 ms) en polarisant convenablement l'anode, la cathode et les grilles au moyen de l'électronique de commande. Pour un écran couleur, les bandes d'éléments luminophores 7 de l'anode 5 sont séquentiellement polarisées, durant une trame, par ensembles de bandes d'une même couleur, soit pendant une durée de sous-trame correspondant au tiers du temps de trame (par exemple 6,6 ms).The display of an image takes place during a frame time (for example 20 ms) by suitably polarizing the anode, the cathode and the grids by means of the control electronics. For a color screen, the bands of phosphor elements 7 of the anode 5 are sequentially polarized, during a frame, by sets of bands of the same color, that is to say for a duration of sub-frame corresponding to one third of the frame time (for example 6.6 ms).

Selon l'invention, l'affichage s'effectue ligne par ligne mais de façon entrelacée, pendant chaque sous-trame. En d'autres termes, on commence par adresser un des peignes (par exemple 24) de la seconde grille 23 et on adresse, séquentiellement, toutes les rangées 21 de la première grille 20 pendant un "temps de ligne" durant lequel chaque colonne 28 de la cathode 1 est portée à un potentiel qui est fonction de la brillance du pixel à afficher le long de la piste (par exemple 26) associée à la rangée 21 courante dans la couleur considérée. Puis, on adresse l'autre peigne (par exemple 25) de la seconde grille 23 et on adresse de nouveau, séquentiellement, toutes les rangées 21 de la première grille 20 pendant un "temps de ligne" durant lequel chaque colonne 28 de la cathode 1 est portée à un potentiel qui est fonction de la brillance du pixel à afficher le long de la piste (par exemple 27) associée à la rangée 21 courante dans la couleur considérée.According to the invention, the display is carried out line by line but in an interlaced manner, during each sub-frame. In other words, we start by addressing one of the combs (for example 24) of the second grid 23 and we address, sequentially, all the rows 21 of the first grid 20 during a "row time" during which each column 28 of cathode 1 is brought to a potential which is a function of the brightness of the pixel to be displayed along the track (for example 26) associated with the current row 21 in the color considered. Then, the other comb (for example 25) of the second grid 23 is addressed and again, sequentially, all the rows 21 of the first grid 20 are addressed during a "row time" during which each column 28 of the cathode 1 is brought to a potential which is a function of the brightness of the pixel to be displayed along the track (for example 27) associated with the current row 21 in the color considered.

La polarisation des colonnes 28 de la cathode 1 change à chaque nouvelle rangée 21 du balayage ligne de la première grille 20. Un "temps de ligne" (par exemple 13,7 µs) correspond à la durée d'une sous-trame divisée par le nombre de rangées 21 de la première grille 20 multipliée par le nombre de peignes de la seconde grille 23.The polarization of the columns 28 of the cathode 1 changes with each new row 21 of the line scanning of the first grid 20. A "line time" (for example 13.7 μs) corresponds to the duration of a sub-frame divided by the number of rows 21 of the first grid 20 multiplied by the number of combs of the second grid 23.

Pendant qu'un peigne (par exemple 24) est adressé, les électrons, émis par les micropointes situées à l'aplomb de la piste (par exemple 27) de l'autre peigne (par exemple 25) et de la rangée courante 21 de la première grille 20, sont collectés par cette piste (par exemple 27).While a comb (for example 24) is being addressed, the electrons, emitted by the microtips located directly above the track (for example 27) of the other comb (for example 25) and of the current row 21 of the first grid 20, are collected by this track (for example 27).

Ce fonctionnement est illustré par la figure 3 qui représente, partiellement et en perspective éclatée, un conducteur 28 de la cathode 1 et les deux grilles 20 et 23 selon l'invention. Comme dans le cas de la figure 2, seuls une micropointe 2 et un trou 4 par pixel ont été représentés.This operation is illustrated by FIG. 3 which shows, partially and in exploded perspective, a conductor 28 of the cathode 1 and the two grids 20 and 23 according to the invention. As in the case of FIG. 2, only a microtip 2 and a hole 4 per pixel have been represented.

On suppose dans cette figure que le peigne 24 ainsi que la rangée 21 représentée de la première grille 20 sont adressés. Ainsi, les électrons émis par la micropointe 2', en regard de la piste 26 du peigne 24, sont focalisés vers l'anode (non représentée) tandis que les électrons émis par la micropointe 2", en regard de la piste 27 du peigne 25, sont collectés par cette piste 27.It is assumed in this figure that the comb 24 and the row 21 shown in the first grid 20 are addressed. Thus, the electrons emitted by the microtip 2 ′, facing the track 26 of the comb 24, are focused towards the anode (not shown) while the electrons emitted by the microtip 2 ", opposite the track 27 of the comb 25, are collected by this track 27.

Le potentiel VG d'une rangée 21 de la première grille 20 qui est adressée est, comme pour les écrans classiques, par exemple de 80 volts alors qu'il est de 0 volt pour les rangées 21 qui ne sont pas adressées. Le potentiel VK des colonnes 28 de la cathode est, comme pour les écrans classiques, par exemple compris entre 0 et 30 volts en fonction de la brillance souhaitée pour le pixel considéré.The potential V G of a row 21 of the first grid 20 which is addressed is, as for conventional screens, for example of 80 volts while it is 0 volts for the rows 21 which are not addressed. The potential V K of the columns 28 of the cathode is, as for conventional screens, for example between 0 and 30 volts depending on the desired brightness for the pixel considered.

Pour permettre la focalisation des électrons, le potentiel Vf des pistes d'un peigne adressé est supérieur au potentiel des rangées 21 qui ne sont pas adressées. Si la première grille 20 est polarisée entre 0 et 80 volts, on choisira, par exemple, un potentiel Vf de l'ordre de 5 volts pour le peigne focalisateur.To allow focusing of the electrons, the potential V f of the tracks of an addressed comb is greater than the potential of the rows 21 which are not addressed. If the first grid 20 is polarized between 0 and 80 volts, we will choose, for example, a potential V f of the order of 5 volts for the focusing comb.

Pour permettre la collecte des électrons par les pistes de l'autre peigne, le potentiel Vc de celui-ci est inférieur au potentiel des rangées 21 qui ne sont pas adressées. Si la première grille 20 est polarisée entre 0 et 80 volts, on choisira, par exemple, un potentiel Vc de l'ordre de -5 volts pour le peigne collecteur.To allow the collection of electrons by the tracks of the other comb, the potential V c thereof is lower than the potential of the rows 21 which are not addressed. If the first grid 20 is polarized between 0 and 80 volts, we will choose, for example, a potential V c of the order of -5 volts for the collector comb.

Le nombre de peignes de la seconde grille 23 est choisi en fonction du nombre d'étages de sortie, ou de connexions, souhaités pour les grilles et/ou de la définition souhaitée pour l'écran dans la direction des colonnes 28 de la cathode 1 et/ou de la forme sous laquelle arrivent les consignes de luminance dans l'électronique de commande.The number of combs of the second grid 23 is chosen according to the number of output stages, or connections, desired for the grids and / or the desired definition for the screen in the direction of the columns 28 of the cathode 1 and / or the form in which the luminance setpoints arrive in the control electronics.

Un mode de réalisation à deux peignes, tel que représenté aux figures 2 et 3, se prête particulièrement bien à des signaux de télévision dans lesquels les lignes sont généralement entrelacées.An embodiment with two combs, as shown in Figures 2 and 3, lends itself particularly well to television signals in which the lines are generally interlaced.

On pourra également prévoir que la seconde grille 23 soit constituée de trois peignes avec un peigne par couleur.We can also provide that the second grid 23 consists of three combs with one comb per color.

On pourra encore prévoir que la seconde grille 23 comporte un plus grand nombre de peignes. Par exemple, on peut envisager que l'image numérisée soit enregistrée dans une mémoire de trame dont on peut facilement lire le contenu par sauts de huit. On pourra alors, avantageusement, prévoir huit peignes pour la seconde grille 23 et permettre ainsi de visualiser huit sous-trames entrelacées successives.We can also provide that the second grid 23 has a greater number of combs. For example, it is conceivable that the scanned image is saved in a frame memory whose content can easily be read in jumps of eight. It is then advantageously possible to provide eight combs for the second grid 23 and thus make it possible to view eight successive interlaced subframes.

Un avantage de la présente invention est que pour un écran d'un nombre N de lignes donné, le nombre d'étages de sortie de l'électronique de commande associés aux grilles, donc de connexions des grilles à l'électronique de commande, est de M + N/M, où M représente le nombre de peignes de la seconde grille 23. Dans l'exemple représenté aux figures 2 et 3, on réduit presque de moitié le nombre d'étages de sortie et de connexions nécessaires pour les grilles.An advantage of the present invention is that for a screen of a given number N of lines, the number of output stages of the control electronics associated with the gates, therefore of connections of the gates to the control electronics, is of M + N / M, where M represents the number of combs of the second grid 23. In the example shown in FIGS. 2 and 3, the number of output stages and connections necessary for the grids is almost halved .

A titre d'exemple particulier de réalisation, un écran, selon l'invention, de 288 lignes par 360 colonnes dont la seconde grille comporte deux peignes peut être réalisé en ayant recours à 146 (144 pour les rangées 21 et 2 pour les peignes 24 et 25) étages de sorties et connexions associés aux grilles.As a particular embodiment, a screen, according to the invention, of 288 rows by 360 columns, the second grid of which has two combs can be produced by using 146 (144 for rows 21 and 2 for combs 24 and 25) output stages and connections associated with the gates.

Un autre avantage de la présente invention est qu'elle permet de réduire le nombre d'étages de sortie et de connexions sans modification de la structure de la cathode et de l'anode de l'écran, ni de l'électronique de commande associée à la cathode et à l'anode.Another advantage of the present invention is that it makes it possible to reduce the number of output stages and connections without modifying the structure of the cathode and the anode of the screen, nor of the associated control electronics. at the cathode and at the anode.

Un autre avantage de la présente invention est qu'elle permet de réaliser des écrans de haute définition et de petites dimensions, où au moins une des dimensions d'un pixel est inférieure au pas minimal entre les connexions des rangées de grille. En effet, pour un écran réalisé avec un pas de rangées 21 de la première grille 20 qui correspond au pas minimal réalisable (par exemple 200 µm), la mise en oeuvre de l'invention permet d'augmenter la définition de l'écran, au moins dans la direction perpendiculaire aux rangées de la grille, d'un facteur de M correspondant au nombre de peignes de la seconde grille 23. Dans l'exemple représenté aux figures 2 et 3, cela revient à doubler la définition de l'écran dans cette direction.Another advantage of the present invention is that it makes it possible to produce screens of high definition and of small dimensions, where at least one of the dimensions of a pixel is less than the minimum pitch between the connections of the grid rows. Indeed, for a screen produced with a pitch of rows 21 of the first grid 20 which corresponds to the minimum achievable pitch (for example 200 μm), the implementation of the invention makes it possible to increase the definition of the screen, at least in the direction perpendicular to the rows of the grid, by a factor of M corresponding to the number of combs of the second grid 23. In the example shown in Figures 2 and 3, this amounts to doubling the definition of the screen in that direction.

Pour que la définition de l'écran puisse être augmentée dans les deux directions, il faut que les connexions des colonnes de la cathode et/ou de la première grille le permettent. Pour ce faire, on peut prévoir, par exemple, que l'emplacement des connexions des colonnes de la cathode soit alternativement à une ou l'autre des extrémités de ces colonnes, ce qui permet de doubler la définition de l'écran dans la direction des rangées de la grille.So that the screen definition can be increased in both directions, the connections of the cathode columns and / or the first grid must be allow. To do this, one can provide, for example, that the location of the connections of the cathode columns is alternately at one or the other of the ends of these columns, which makes it possible to double the definition of the screen in the direction grid rows.

A titre d'exemple particulier de réalisation, un écran carré de 1024 pixels de côté peut, selon l'invention, être réalisé sur une surface de 10 cm de côté. Le pas des pixels est alors de l'ordre de 0,1 mm. Le pas des rangées 21 de la première grille est de 0,2 mm ce qui est compatible avec le pas minimal des connexions classiques. Chaque piste 26 ou 27 de la seconde grille 23 présente, par exemple, une largeur de l'ordre de 75 µm et deux pistes voisines sont distantes d'environ 25 µm.As a particular embodiment, a square screen of 1024 pixels side can, according to the invention, be produced on a surface of 10 cm side. The pixel pitch is then of the order of 0.1 mm. The pitch of rows 21 of the first grid is 0.2 mm, which is compatible with the minimum pitch of conventional connections. Each track 26 or 27 of the second grid 23 has, for example, a width of the order of 75 μm and two neighboring tracks are spaced about 25 μm apart.

Bien entendu, la présente invention est susceptible de diverses variantes et modifications qui apparaîtront à l'homme de l'art. En particulier, chacun des éléments décrits pourra être remplacé par un ou plusieurs éléments remplissant la même fonction. De même, les dimensions et potentiels donnés à titre d'exemple pourront être modifiés en fonction de la définition et des caractéristiques de l'écran.Of course, the present invention is susceptible of various variants and modifications which will appear to those skilled in the art. In particular, each of the elements described may be replaced by one or more elements fulfilling the same function. Likewise, the dimensions and potentials given by way of example may be modified according to the definition and characteristics of the screen.

De plus, bien que l'on ait fait référence dans la description qui précède à un écran couleur, l'invention s'applique également à un écran monochrome que son anode soit, ou non, constituée d'un plan continu d'éléments luminophores.In addition, although reference has been made in the foregoing description to a color screen, the invention also applies to a monochrome screen whether or not its anode consists of a continuous plane of phosphor elements .

En outre, l'invention s'applique également à un écran fluorescent dont la cathode est constituée à partir d'un film, par exemple de carbone-diamant, d'émission électronique.In addition, the invention also applies to a fluorescent screen, the cathode of which is formed from a film, for example of carbon-diamond, of electronic emission.

Claims (8)

Ecran plat de visualisation du type comportant une cathode (1) organisée en colonnes (28) de bombardement électronique d'une anode (5) pourvue d'éléments luminophores (7), caractérisé en ce qu'il comporte une première grille (20) organisée en rangées (21) susceptibles d'être adressées individuellement et une seconde grille (23) constituée d'au moins deux peignes (24, 25) de pistes (26, 27) alternées parallèles auxdites rangées (21) de ladite première grille (20), une même rangée (21) de ladite première grille (20) étant associée à une piste (26, 27) de chaque peigne (24, 25) et l'intersection de chaque piste (26, 27) avec une colonne (28) de la cathode (1) définissant un pixel de l'écran.Flat display screen of the type comprising a cathode (1) organized in columns (28) of electronic bombardment of an anode (5) provided with phosphor elements (7), characterized in that it comprises a first grid (20) organized in rows (21) capable of being addressed individually and a second grid (23) consisting of at least two combs (24, 25) of alternating tracks (26, 27) parallel to said rows (21) of said first grid ( 20), the same row (21) of said first grid (20) being associated with a track (26, 27) of each comb (24, 25) and the intersection of each track (26, 27) with a column ( 28) of the cathode (1) defining a pixel of the screen. Ecran plat de visualisation selon la revendication 1, caractérisé en ce que l'affichage d'une image s'effectue, de manière entrelacée, en adressant séquentiellement lesdites rangées (21) de la première grille (20) pendant la durée d'un adressage alternatif desdits peignes (24, 25) de la seconde grille (23).Flat display screen according to claim 1, characterized in that the display of an image is effected, in an interlaced manner, by sequentially addressing said rows (21) of the first grid (20) for the duration of an addressing of said combs (24, 25) of the second grid (23). Ecran plat de visualisation selon la revendication 2, caractérisé en ce que les colonnes (28) de la cathode (1) sont adressées simultanément à chaque rangée (21) de la première grille (20), leur potentiel étant fonction de la brillance souhaitée pour le pixel défini par leur intersection avec la piste (26, 27) du peigne (24, 25) adressé de la seconde grille (23) qui se trouve à l'aplomb de la rangée (21) courante.Flat display screen according to claim 2, characterized in that the columns (28) of the cathode (1) are addressed simultaneously to each row (21) of the first grid (20), their potential being a function of the desired brightness for the pixel defined by their intersection with the track (26, 27) of the comb (24, 25) addressed from the second grid (23) which is plumb with the current row (21). Ecran plat de visualisation selon la revendication 2 ou 3, caractérisé en ce que les potentiels de polarisation desdits peignes (24, 25) sont choisis pour que les pistes (26, 27) d'un peigne (24, 25) adressé focalisent, vers l'anode (5), les électrons émis par les colonnes (28) de la cathode (1) à l'aplomb de la piste (26, 27) dudit peigne focalisateur associée à une rangée (21) adressée, et pour que les pistes (27, 26) d'un peigne (25, 24) qui n'est pas adressé collectent les électrons émis par les colonnes (28) de la cathode (1) à l'aplomb de la piste (27, 26) dudit peigne collecteur associée à la rangée (21) adressée.Flat display screen according to claim 2 or 3, characterized in that the polarization potentials of said combs (24, 25) are chosen so that the tracks (26, 27) of a comb (24, 25) addressed focus, towards the anode (5), the electrons emitted by the columns (28) of the cathode (1) directly above the track (26, 27) of said focusing comb associated with a row (21) addressed, and so that the tracks (27, 26) of a comb (25, 24) which is not addressed collect the electrons emitted by the columns (28) of the cathode (1) directly above the track (27, 26) of said collecting comb associated with the row (21) addressed. Ecran plat de visualisation selon la revendication 4, caractérisé en ce que le potentiel d'un peigne (24, 25) focalisateur est supérieur au potentiel des rangées (21) de la première grille (20) qui ne sont pas adressées, le potentiel d'un peigne (25, 24) collecteur étant inférieur au potentiel des rangées (21) de la première grille (20) qui ne sont pas adressées.Flat display screen according to claim 4, characterized in that the potential of a focusing comb (24, 25) is greater than the potential of the rows (21) of the first grid (20) which are not addressed, the potential d 'a comb (25, 24) collector being less than the potential of the rows (21) of the first grid (20) which are not addressed. Ecran plat de visualisation selon l'une quelconque des revendications 1 à 5, caractérisé en ce que le pas des rangées (21) de la première grille (20) est dimensionné en fonction du pas minimal devant être respecté entre les connexions individuelles de ces rangées (21) vers une électronique de commande, le nombre de peignes (24, 25) de la seconde grille (23) étant choisi en fonction de la définition souhaitée pour l'écran.Flat display screen according to any one of Claims 1 to 5, characterized in that the pitch of the rows (21) of the first grid (20) is dimensioned as a function of the minimum pitch to be respected between the individual connections of these rows (21) to control electronics, the number of combs (24, 25) of the second grid (23) being chosen according to the definition desired for the screen. Ecran plat de visualisation selon l'une quelconque des revendications 1 à 6, caractérisé en ce que lesdites grilles (20, 21) sont appliquées à un écran couleur dont l'anode (5) est pourvue de trois ensembles de bandes alternées d'éléments luminophores (7) correspondant chacun à une couleur.Flat display screen according to any one of claims 1 to 6, characterized in that said grids (20, 21) are applied to a color screen whose anode (5) is provided with three sets of alternating strips of elements phosphors (7) each corresponding to a color. Ecran plat de visualisation selon l'une quelconque des revendications 1 à 6, caractérisé en ce que lesdites grilles (20, 21) sont appliquées à un écran monochrome dont l'anode (5) est constituée d'éléments luminophores (7) d'un seul type.Flat display screen according to any one of claims 1 to 6, characterized in that said grids (20, 21) are applied to a monochrome screen whose anode (5) consists of phosphor elements (7) of only one type.
EP96410030A 1995-03-22 1996-03-21 Double-gated flat display screen Expired - Lifetime EP0734043B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9503570 1995-03-22
FR9503570A FR2732159B1 (en) 1995-03-22 1995-03-22 DOUBLE GRID DISPLAY FLAT SCREEN

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EP0734043A1 true EP0734043A1 (en) 1996-09-25
EP0734043B1 EP0734043B1 (en) 2000-05-31

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EP (1) EP0734043B1 (en)
JP (1) JPH08293273A (en)
DE (1) DE69608598T2 (en)
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DE69608598D1 (en) 2000-07-06
DE69608598T2 (en) 2001-02-08
FR2732159B1 (en) 1997-06-13
US5764204A (en) 1998-06-09
FR2732159A1 (en) 1996-09-27
JPH08293273A (en) 1996-11-05
EP0734043B1 (en) 2000-05-31

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