EP0877407A1 - Anode of a flat display screen - Google Patents

Anode of a flat display screen Download PDF

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Publication number
EP0877407A1
EP0877407A1 EP98410045A EP98410045A EP0877407A1 EP 0877407 A1 EP0877407 A1 EP 0877407A1 EP 98410045 A EP98410045 A EP 98410045A EP 98410045 A EP98410045 A EP 98410045A EP 0877407 A1 EP0877407 A1 EP 0877407A1
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EP
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Prior art keywords
anode
strips
bands
focusing
insulation
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EP98410045A
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German (de)
French (fr)
Inventor
Axel Jäger
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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
    • H01J29/02—Electrodes; Screens; Mounting, supporting, spacing or insulating thereof
    • H01J29/08—Electrodes intimately associated with a screen on or from which an image or pattern is formed, picked-up, converted or stored, e.g. backing-plates for storage tubes or collecting secondary electrons
    • H01J29/085—Anode plates, e.g. for screens of flat panel displays

Definitions

  • the present invention relates to flat screens of display, and more particularly so-called cathodoluminescence screens, whose anode carries luminescent elements, separated from each other by insulating zones, and susceptible to be excited by electronic bombardment.
  • This bombing electronics requires the luminescent elements to be polarized and can come from microtips, low-lying layers potential for extraction or thermionic source.
  • Figure 1 shows the structure of a flat screen microtip color.
  • Such a microtip screen essentially consists 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 glass substrate 6 constitutes the screen surface.
  • Cathode 1 is organized in columns and is made up, on a glass substrate 10, cathode conductors organized in mesh from a conductive layer.
  • the microtips 2 are made on a resistive layer 11 deposited on the cathode conductors and are arranged inside meshes defined by the cathode conductors.
  • Figure 1 partially represents the interior of a mesh and the conductors cathode do not appear in this figure.
  • Cathode 1 is associated with grid 3 organized in lines. The intersection a row of grid 3 and a column of cathode 1 defines a pixel.
  • This device uses the electric field which is created between the cathode 1 and the grid 3 so that electrons are extracted from the microtips 2. These electrons are then attracted by phosphor elements 7 from the anode 5 if these are suitably polarized.
  • the anode 5 is provided with alternating bands of phosphor elements 7r, 7g, 7b each corresponding to a color (Red, Green, Blue). The strips are parallel to the columns of the cathode and are separated from each other by an insulator 8, generally silicon oxide (SiO 2 ).
  • the phosphor elements 7 are deposited on electrodes 9, made up of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO).
  • ITO indium tin oxide
  • the sets of red, green and blue bands are alternately polarized with respect to the cathode 1, so that electrons extracted from the microtips 2 of a pixel of the cathode / grid are alternately directed towards the phosphor elements 7 opposite of each of the colors.
  • the rows of grid 3 are sequentially polarized at a potential on the order of 80 volts, while that the bands of phosphor elements (for example 7g in Figure 1) to be excited are biased under a voltage of the order of 400 volts via the ITO strip on which these phosphor elements are deposited.
  • Groups of ITO, carrying the other bands of phosphor elements (for example example 7r and 7b in figure 1), are at a low or zero potential.
  • the columns of cathode 1 are brought to respective potentials between a maximum emission potential and a no emission potential (for example 0 and 0 respectively 30 volts). We thus fix the brightness of a color component of each of the pixels in a line.
  • the choice of the values of the polarization potentials is linked to the characteristics of the phosphor elements 7 and microtips 2. Conventionally, below a difference of potential of 50 volts between the cathode and the grid, there is no electronic emission, and the maximum emission used corresponds at a potential difference of 80 volts.
  • a disadvantage of conventional screens is that they suffer a short lifespan, that is to say after relatively short operating time (around a hundred hours), the screen brightness decreases considerably and we even sometimes see destructive phenomena appear due to the formation of arcs between the cathode and the anode of the screen.
  • drift colored In practice, this means that at least one of the strips of phosphor material adjacent to the polarized strips begins to exhibit luminescence.
  • a first known technique to avoid this phenomenon of parasitic illumination consists in separating, by intervals of short times, the polarizations of the anode bands between two successive color subframes, and to apply a pulse of negative voltage on the strip which has just been polarized before positively bias the next anode strip to be excited.
  • a second known technique consists in depositing, on the isolation bands separating the phosphor bands, a conductive layer polarized at a negative or zero potential. Such a technique is described, for example, in document EP-A-0 635 865. The role of the conductive layer is then to prevent the emission of secondary electrons by the insulating layer of SiO 2 , and the creation of 'a positive charge zone between two bands of phosphor elements.
  • a drawback of this technique is that, in order not to harm the insulation between the anode strips, the insulation strips must be thick (of the order of 50 ⁇ m) so that the phosphor elements deposited (on a thickness of the order of 10 ⁇ m) between these strips are buried with respect to the conductive layer.
  • Another drawback is that the implementation of this technique lengthens the manufacturing time. Indeed, to be precise, the etching of the SiO 2 coating must be carried out by plasma, which is particularly long for such a thickness.
  • the thickness of the strips insulation must be chosen according to the resistivity of the phosphor elements while this resistivity may be different from one color to another.
  • the phosphor elements are generally deposited by screen printing.
  • the alignment of the screen printing mask with the etching pattern is, in practice, imperfect, so that phosphor elements often protrude slightly from the holes in the SiO 2 layer. In such a case, the insulation is no longer respected, because these overflows take place on the conductive layer.
  • the present invention aims to propose a new solution to the above screen life issues and color drift, which overcomes the disadvantages of the solutions known.
  • the invention aims, in particular, to propose a new solution to the problem of stray lighting linked to switching of the anode strips.
  • the present invention also aims to provide a solution compatible with conventional manufacturing processes of the screen and which does not require an additional step in the manufacturing process of the anode.
  • the present invention provides a flat screen display anode of the type comprising at least two sets of alternating parallel strips of conductors anode coated with phosphor elements, separated one from the other others by isolation bands and polarizable at different potentials depending on the phosphor elements to excite, and focusing conductive strips, aligned and substantially centered with the insulation bands, the bands focusing conductors having widths less than those of the isolation bands.
  • the focusing bands are polarized at a negative potential or zero.
  • the thickness of the insulation strips is between 1 and 5 ⁇ m.
  • the focusing strips are deposited on the isolation strips.
  • the width of the focusing conductive strips represents between 20 and 60% of the width of the insulation strips.
  • the focusing bands are buried in the isolation bands.
  • the difference between a focusing band and a neighboring band of anode conductor is chosen to support a difference of determined potential between these two neighboring bands, the width focusing conductive strips preferably representing 20 to 90% of the difference between two neighboring strips of conductors anode.
  • the focusing strips are made of the same material as the anode conductor strips.
  • the present invention also relates to a method of realization of a flat screen display anode in which the mask for defining the anode conductor strips defines also the pattern of the focusing conductive strips.
  • the present invention also relates to a flat screen display comprising a microtip cathode and a anode consisting of at least two sets of alternating strips phosphor elements and provided with focusing strips.
  • Figure 2 shows, partially and in section, a anode according to a first embodiment of the present invention.
  • the anode 5 ' is produced on a substrate 6, by glass temple, and is provided with alternating bands of phosphor elements 7r, 7g, 7b each corresponding to a color (Red, Green, Blue).
  • the strips are separated from each other by an insulator 8, generally silicon oxide (SiO 2 ).
  • the phosphor elements 7 are deposited on electrodes 9r, 9g, 9b, made up of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO).
  • ITO indium tin oxide
  • additional conductive strips 19 are deposited on the insulating strips 8 separating two strips of phosphor elements neighbors.
  • the width of the strips additional 19 is less than the space separating two bands neighboring phosphor elements and therefore does not entirely cover the insulating strips 8.
  • the strips 19 are substantially centered on the insulating strips 8 and their width represents, for for example, 20 to 60% of the width of the strips 8.
  • the bands 19 are polarized at a potential at most equal to the minimum potential for polarization of the cathode to create an electric field repelling electrons emitted by microtips (not shown).
  • the bands 19 then have a focusing effect of the electrons emitted by the cathode to the bands 9 carrying the phosphor elements.
  • the energy of these electrons is extremely low (close to 0 electron volts) and these electrons are then unable to cause the emission of secondary electrons.
  • the parts 18 of insulation remaining on each side of each strip 19 provide insulation between these additional conductive strips and strips of phosphor elements without it necessary to increase the thickness of the insulating strips 8.
  • the insulating strips 8 have a thickness in accordance with the conventional precedents of realization a flat screen anode, for example, between 1 and 5 ⁇ m.
  • Another advantage compared to the known technique of EP-A-0635865 is that the misalignments between the deposition mask by screen printing of the phosphor elements by compared to the etching pattern of layer 8 is not a problem.
  • the possible overflows of the phosphor elements are here deposited on the insulating parts 18.
  • the thickness of the strips of phosphor elements is generally of the order of 10 ⁇ m.
  • Figures 3 and 4 show respectively in section and seen from below, a second embodiment of a color flat screen anode according to the present invention. To the Figure 4, the phosphor elements have not been shown.
  • a feature of this embodiment is provide between two neighboring conductive strips 9 carrying phosphor elements, an additional conductive strip 29, coated with insulating layer 8 separating the strips 9 together others.
  • these bands 29 are polarized at a potential at most equal to the minimum potential cathode polarization to create an electric field repelling the electrons emitted by the microtips.
  • the bands 29 are substantially centered between two neighboring bands 9 and preferably have a width comprised between 20 and 90% of the difference between two neighboring bands.
  • the focusing strips 29 can be wider than in the first embodiment.
  • the gap between a strip 29 and a band 9 is in fact only linked to the need for isolation between these tapes and need not guarantee isolation in the event of overflow of phosphor elements. Plus the focusing strips are large, the greater the focusing effect for a given potential.
  • the width strips 9 of anode conductors is of the order of 80 ⁇ m and the gap between two neighboring strips of anode conductors is on the order of 40 ⁇ m.
  • the bands 29 are made of the same material (eg ITO) that the bands 9 carrying the elements phosphors.
  • ITO the same material
  • An advantage of such an embodiment is that the production of an anode according to the invention does not require then no additional step compared to a traditional precedent for manufacturing a flat screen anode.
  • the interconnection of bands 29 to allow their polarization can then be carried out at the same time as the interconnections of the bands 9 are made by set of bands of the same color.
  • FIGS. 5A and 5B illustrate, in sectional views, taken respectively along lines A-A and B-B of FIG. 4, the interconnections of bands 9 and 29 at their ends.
  • the layer 8 is also open to create two pads 15 and 16 ( Figures 5A and 5B) connecting tracks 11 and 12.
  • the openings made at the rights of studs 13, 14 and 15, 16 are filled with a conductive material to transfer the contacts above layer 8.
  • An advantage of the present invention is that the structure planned is perfectly compatible with the steps of a process conventional manufacturing of a flat screen anode.
  • bands 19 or 29 are, for example, polarized at a potential loving between 0 and -200 volts.
  • An advantage of the present invention is that it eliminates the phenomenon of color drift observed on the screens classics.
  • Another advantage of the present invention is that it dramatically improves screen life by removing all risk of arcing between two strips of phosphor elements neighbors.
  • the invention also applies to a monochrome screen in which the phosphor elements of the anode are carried by anode electrodes organized in two sets alternating bands of phosphor elements of the same color.
  • the invention further improves the resolution of the screen which is already better than that of a screen whose anode is consisting of a plan of phosphor elements of the same color.
  • the present invention is capable of various variants and modifications which will appear to the man of art.
  • the polarization potential of the focus and width can be changed depending the type of screen and the polarization potentials of its constituents.

Abstract

The flat anode display screen (5') comprises at least two sets of parallel bands of anode conductors (9) coated with luminophore material (7). These are separated from each other by insulating bands (8) which may be biased to different potentials as a function of the luminophore elements to be excited. The screen also includes focussing conductive bands (19,29) which are aligned and preferably centred with the insulating bands. The focussing bands have widths which are less than those of the insulating bands. The focussing bands may be biased to either a negative voltage, or zero voltage. The thickness of the insulating bands (8) is between 1 and 5 micrometres, whilst the width of the focussing bands is 20 - 60% of this size.

Description

La présente invention concerne les écrans plats de visualisation, et plus particulièrement des écrans dits à cathodoluminescence, dont l'anode porte des éléments luminescents, séparés les uns des autres par des zones isolantes, et susceptibles d'être excités par bombardement électronique. Ce bombardement électronique nécessite que les éléments luminescents soient polarisés et peut provenir de micropointes, de couches à faible potentiel d'extraction ou d'une source thermoionique.The present invention relates to flat screens of display, and more particularly so-called cathodoluminescence screens, whose anode carries luminescent elements, separated from each other by insulating zones, and susceptible to be excited by electronic bombardment. This bombing electronics requires the luminescent elements to be polarized and can come from microtips, low-lying layers potential for extraction or thermionic source.

Pour simplifier la présente description, on ne considérera ci-après que les écrans couleur à micropointes mais on notera que l'invention concerne, de façon générale, les divers types d'écrans susmentionnés et analogues.To simplify this description, we will not consider below as color microtip screens but we note that the invention relates, in general, to the various types of screens mentioned above and the like.

La figure 1 représente la structure d'un écran plat couleur à micropointes.Figure 1 shows the structure of a flat screen microtip color.

Un tel écran à micropointes est essentiellement constitué d'une cathode 1 à micropointes 2 et d'une grille 3 pourvue de trous 4 correspondants 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 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 glass substrate 6 constitutes the screen surface.

Le principe de fonctionnement et un mode de réalisation particulier d'un écran à micropointes sont décrits, en particulier, dans le brevet américain n° 4 940 916 du Commissariat à l'Énergie Atomique.The operating principle and an embodiment particular of a microtip screen are described, in particular, in U.S. Patent No. 4,940,916 to the Commissariat for Atomic Energy.

La cathode 1 est organisée en colonnes et est constituée, sur un substrat de verre 10, 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 représente partiellement l'intérieur d'une maille et les conducteurs de cathode n'apparaissent pas sur cette figure. La cathode 1 est associée à la grille 3 organisée en lignes. L'intersection d'une ligne de la grille 3 et d'une colonne de la cathode 1 définit un pixel.Cathode 1 is organized in columns and is made up, on a glass substrate 10, cathode conductors organized in mesh from a conductive layer. The microtips 2 are made on a resistive layer 11 deposited on the cathode conductors and are arranged inside meshes defined by the cathode conductors. Figure 1 partially represents the interior of a mesh and the conductors cathode do not appear in this figure. Cathode 1 is associated with grid 3 organized in lines. The intersection a row of grid 3 and a column of cathode 1 defines a pixel.

Ce dispositif utilise le champ électrique qui est créé entre la cathode 1 et la grille 3 pour que des électrons soient extraits des micropointes 2. Ces électrons sont ensuite attirés par des éléments luminophores 7 de l'anode 5 si ceux-ci sont convenablement polarisés. Dans le cas d'un écran couleur, l'anode 5 est pourvue de bandes alternées d'éléments luminophores 7r, 7g, 7b correspondant chacune à une couleur (Rouge, Vert, Bleu). Les bandes sont parallèles aux colonnes de la cathode et sont séparées les unes des autres par un isolant 8, généralement de l'oxyde de silicium (SiO2). 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 rouges, vertes, bleues sont alternativement polarisés par rapport à la cathode 1, pour que des 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.This device uses the electric field which is created between the cathode 1 and the grid 3 so that electrons are extracted from the microtips 2. These electrons are then attracted by phosphor elements 7 from the anode 5 if these are suitably polarized. In the case of a color screen, the anode 5 is provided with alternating bands of phosphor elements 7r, 7g, 7b each corresponding to a color (Red, Green, Blue). The strips are parallel to the columns of the cathode and are separated from each other by an insulator 8, generally silicon oxide (SiO 2 ). The phosphor elements 7 are deposited on electrodes 9, made up of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO). The sets of red, green and blue bands are alternately polarized with respect to the cathode 1, so that electrons extracted from the microtips 2 of a pixel of the cathode / grid are alternately directed towards the phosphor elements 7 opposite of each of the colors.

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 par l'intermédiaire de la bande d'ITO sur laquelle ces éléments luminophores sont déposés. Les bandes d'ITO, portant les autres bandes d'éléments luminophores (par exemple 7r et 7b en figure 1), sont à un potentiel faible ou nul. Les colonnes de la cathode 1 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). On fixe ainsi la brillance d'une composante couleur de chacun des pixels d'une ligne.Generally, the rows of grid 3 are sequentially polarized at a potential on the order of 80 volts, while that the bands of phosphor elements (for example 7g in Figure 1) to be excited are biased under a voltage of the order of 400 volts via the ITO strip on which these phosphor elements are deposited. Groups of ITO, carrying the other bands of phosphor elements (for example example 7r and 7b in figure 1), are at a low or zero potential. The columns of cathode 1 are brought to respective potentials between a maximum emission potential and a no emission potential (for example 0 and 0 respectively 30 volts). We thus fix the brightness of a color component of each of the pixels in a line.

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 et la grille, 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 microtips 2. Conventionally, below a difference of potential of 50 volts between the cathode and the grid, there is no electronic emission, and the maximum emission used corresponds at a potential difference of 80 volts.

Un inconvénient des écrans classiques est qu'ils souffrent d'une faible durée de vie, c'est-à-dire qu'au bout d'un temps de fonctionnement relativement court (de l'ordre d'une centaine d'heures), la brillance de l'écran diminue considérablement et on voit même parfois apparaítre des phénomènes destructeurs dus à la formation d'arcs entre la cathode et l'anode de l'écran.A disadvantage of conventional screens is that they suffer a short lifespan, that is to say after relatively short operating time (around a hundred hours), the screen brightness decreases considerably and we even sometimes see destructive phenomena appear due to the formation of arcs between the cathode and the anode of the screen.

De plus, au bout d'un certain temps de fonctionnement, on constate que la couleur varie et ne correspond plus aux consignes de commande de l'écran. Ce phénomène sera appelé ici "dérive de couleur". En pratique, ceci signifie que l'une au moins des bandes de matériau luminophore adjacentes aux bandes polarisées se met à présenter une luminescence.In addition, after a certain period of operation, we see that the color varies and no longer corresponds to the instructions control panel. This phenomenon will be called here "drift colored. "In practice, this means that at least one of the strips of phosphor material adjacent to the polarized strips begins to exhibit luminescence.

Une première technique connue pour éviter ce phénomène d'éclairement parasite consiste à séparer, par des intervalles de temps brefs, les polarisations des bandes d'anode entre deux sous-trames couleurs successives, et à appliquer une impulsion de tension négative sur la bande qui vient d'être polarisée avant de polariser positivement la bande d'anode suivante à exciter.A first known technique to avoid this phenomenon of parasitic illumination consists in separating, by intervals of short times, the polarizations of the anode bands between two successive color subframes, and to apply a pulse of negative voltage on the strip which has just been polarized before positively bias the next anode strip to be excited.

Toutefois, cette technique présente l'inconvénient de compliquer les circuits de fourniture des tensions d'alimentation d'anode, qui sont des tensions de valeurs élevées (quelques centaines de volts), et de nuire à la brillance de l'écran.However, this technique has the disadvantage of complicating supply voltage supply circuits anode, which are voltages of high values (a few hundred volts), and adversely affect the brightness of the screen.

Une deuxième technique connue consiste à déposer, sur les bandes d'isolement séparant les bandes de luminophores, une couche conductrice polarisée à un potentiel négatif ou nul. Une telle technique est décrite, par exemple, dans le document EP-A-0 635 865. Le rôle de la couche conductrice est alors d'empêcher l'émission d'électrons secondaires par la couche isolante en SiO2, et la création d'une zone de charge positive entre deux bandes d'éléments luminophores.A second known technique consists in depositing, on the isolation bands separating the phosphor bands, a conductive layer polarized at a negative or zero potential. Such a technique is described, for example, in document EP-A-0 635 865. The role of the conductive layer is then to prevent the emission of secondary electrons by the insulating layer of SiO 2 , and the creation of 'a positive charge zone between two bands of phosphor elements.

Toutefois, un inconvénient de cette technique est que, pour ne pas nuire à l'isolement entre les bandes d'anode, les bandes d'isolement doivent être épaisses (de l'ordre de 50µm) pour que les éléments luminophores déposés (sur une épaisseur de l'ordre de 10 µm) entre ces bandes soient enterrés par rapport à la couche conductrice. Un autre inconvénient est que la mise en oeuvre de cette technique allonge la durée de fabrication. En effet, pour être précise, la gravure de la coucha de SiO2 doit être effectuée par plasma, ce qui est particulièrement long pour une telle épaisseur.However, a drawback of this technique is that, in order not to harm the insulation between the anode strips, the insulation strips must be thick (of the order of 50 μm) so that the phosphor elements deposited (on a thickness of the order of 10 μm) between these strips are buried with respect to the conductive layer. Another drawback is that the implementation of this technique lengthens the manufacturing time. Indeed, to be precise, the etching of the SiO 2 coating must be carried out by plasma, which is particularly long for such a thickness.

Un autre inconvénient est que l'épaisseur des bandes d'isolement doit être choisie en fonction de la résistivité des éléments luminophores alors que cette résistivité peut être différente d'une couleur à l'autre.Another disadvantage is that the thickness of the strips insulation must be chosen according to the resistivity of the phosphor elements while this resistivity may be different from one color to another.

En outre, les éléments luminophores sont généralement déposés par sérigraphie. Or, l'alignement du masque de sérigraphie avec le motif de gravure est, en pratique, imparfait, de sorte que des éléments luminophores débordent souvent légèrement des trous de la couche en SiO2. Dans un tel cas, l'isolement n'est plus respecté, car ces débordements s'effectuent sur la couche conductrice.In addition, the phosphor elements are generally deposited by screen printing. However, the alignment of the screen printing mask with the etching pattern is, in practice, imperfect, so that phosphor elements often protrude slightly from the holes in the SiO 2 layer. In such a case, the insulation is no longer respected, because these overflows take place on the conductive layer.

La présente invention vise à proposer une nouvelle solution aux problèmes susmentionnés de durée de vie de l'écran et de dérive de couleur, qui pallie les inconvénients des solutions connues. The present invention aims to propose a new solution to the above screen life issues and color drift, which overcomes the disadvantages of the solutions known.

L'invention vise, en particulier, à proposer une nouvelle solution au problème d'éclairement parasite lié à la commutation des bandes d'anode.The invention aims, in particular, to propose a new solution to the problem of stray lighting linked to switching of the anode strips.

La présente invention vise également à proposer une solution compatible avec les procédés classiques de fabrication de l'écran et qui ne nécessite pas d'étape supplémentaire dans le procédé de fabrication de l'anode.The present invention also aims to provide a solution compatible with conventional manufacturing processes of the screen and which does not require an additional step in the manufacturing process of the anode.

Pour atteindre ces objets, la présente invention prévoit une anode d'écran plat de visualisation du type comportant au moins deux ensembles de bandes parallèles alternées de conducteurs d'anode revêtues d'éléments luminophores, séparées les unes des autres par des bandes d'isolement et polarisables à des potentiels différents en fonction des éléments luminophores à exciter, et des bandes conductrices de focalisation, alignées et sensiblement centrées avec les bandes d'isolement, les bandes conductrices de focalisation ayant des largeurs inférieures à celles des bandes d'isolement.To achieve these objects, the present invention provides a flat screen display anode of the type comprising at least two sets of alternating parallel strips of conductors anode coated with phosphor elements, separated one from the other others by isolation bands and polarizable at different potentials depending on the phosphor elements to excite, and focusing conductive strips, aligned and substantially centered with the insulation bands, the bands focusing conductors having widths less than those of the isolation bands.

Selon un mode de réalisation de la présente invention, les bandes de focalisation sont polarisées à un potentiel négatif ou nul.According to an embodiment of the present invention, the focusing bands are polarized at a negative potential or zero.

Selon un mode de réalisation de la présente invention, l'épaisseur des bandes d'isolement est comprise entre 1 et 5 µm.According to an embodiment of the present invention, the thickness of the insulation strips is between 1 and 5 μm.

Selon un mode de réalisation de la présente invention, les bandes de focalisation sont déposées sur les bandes d'isolement.According to an embodiment of the present invention, the focusing strips are deposited on the isolation strips.

Selon un mode de réalisation de la présente invention, la largeur des bandes conductrices de focalisation représente entre 20 et 60% de la largeur des bandes d'isolement.According to an embodiment of the present invention, the width of the focusing conductive strips represents between 20 and 60% of the width of the insulation strips.

Selon un mode de réalisation de la présente invention, les bandes de focalisation sont enterrées dans les bandes d'isolement.According to an embodiment of the present invention, the focusing bands are buried in the isolation bands.

Selon un mode de réalisation de la présente invention, l'écart entre une bande de focalisation et une bande voisine de conducteur d'anode est choisi pour supporter une différence de potentiel déterminée entre ces deux bandes voisines, la largeur des bandes conductrices de focalisation représentant, de préférence, 20 à 90% de l'écart entre deux bandes voisines de conducteurs d'anode.According to an embodiment of the present invention, the difference between a focusing band and a neighboring band of anode conductor is chosen to support a difference of determined potential between these two neighboring bands, the width focusing conductive strips preferably representing 20 to 90% of the difference between two neighboring strips of conductors anode.

Selon un mode de réalisation de la présente invention, les bandes de focalisation sont constituées du même matériau que les bandes de conducteurs d'anode.According to an embodiment of the present invention, the focusing strips are made of the same material as the anode conductor strips.

La présente invention concerne également un procédé de réalisation d'une anode d'écran plat de visualisation dans lequel le masque de définition des bandes de conducteurs d'anode définit également le motif des bandes conductrices de focalisation.The present invention also relates to a method of realization of a flat screen display anode in which the mask for defining the anode conductor strips defines also the pattern of the focusing conductive strips.

La présente invention concerne également un écran plat de visualisation comportant une cathode à micropointes et une anode constituée d'au moins deux ensembles de bandes alternées d'éléments luminophores et pourvue de bandes focalisatrices.The present invention also relates to a flat screen display comprising a microtip cathode and a anode consisting of at least two sets of alternating strips phosphor elements and provided with focusing strips.

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, partiellement et en coupe, une anode d'écran plat couleur selon un premier mode de réalisation de la présente invention ;
  • la figure 3 représente, partiellement et en coupe, une anode d'écran plat couleur selon un deuxième mode de réalisation de la présente invention ;
  • la figure 4 représente, en vue de dessous, une anode d'écran plat telle que représentée à la figure 3 ; et
  • les figures 5A et 5B sont des vues partielles en coupe, respectivement, selon les lignes A-A et B-B de la figure 4.
    • 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;
  • Figure 2 shows, partially and in section, a color flat screen anode according to a first embodiment of the present invention;
  • Figure 3 shows, partially and in section, a color flat screen anode according to a second embodiment of the present invention;
  • Figure 4 shows, in bottom view, a flat screen anode as shown in Figure 3; and
  • FIGS. 5A and 5B are partial sectional views, respectively, along the lines AA and BB of FIG. 4.

    • Les mêmes éléments ont été désignés par les mêmes références aux différentes figures. Pour des raisons de clarté, les figures ne sont pas à l'échelle, et seuls les éléments nécessaires à la compréhension de l'invention ont été représentés et seront décrits par la suite.The same elements have been designated by the same references to the different figures. For reasons of clarity, the figures are not to scale, and only the necessary elements to the understanding of the invention have been represented and will be described later.

    La figure 2 représente, partiellement et en coupe, une anode selon un premier mode de réalisation de la présente invention.Figure 2 shows, partially and in section, a anode according to a first embodiment of the present invention.

    Comme précédement, l'anode 5' est réalisée sur un substrat 6, par temple en verre, et est pourvue de bandes alternées d'éléments luminophores 7r, 7g, 7b correspondant chacune à une couleur (Rouge, Vert, Bleu). Les bandes sont séparées les unes des autres par un isolant 8, généralement de l'oxyde de silicium (SiO2). Les éléments luminophores 7 sont déposés sur des électrodes 9r, 9g, 9b, constituées de bandes correspondantes d'une couche conductrice transparente telle que de l'oxyde d'indium et d'étain (ITO).As before, the anode 5 'is produced on a substrate 6, by glass temple, and is provided with alternating bands of phosphor elements 7r, 7g, 7b each corresponding to a color (Red, Green, Blue). The strips are separated from each other by an insulator 8, generally silicon oxide (SiO 2 ). The phosphor elements 7 are deposited on electrodes 9r, 9g, 9b, made up of corresponding strips of a transparent conductive layer such as indium tin oxide (ITO).

    Selon ce premier mode de réalisation de l'invention, des bandes conductrices additionnelles 19 sont déposées sur les bandes isolantes 8 séparant deux bandes d'éléments luminophores voisines. Selon la présente invention, la largeur des bandes additionnelles 19 est inférieure à l'espace séparant deux bandes d'éléments luminophores voisines et ne recouvre donc pas entièrement les bandes isolantes 8. Les bandes 19 sont sensiblement centrées sur les bandes isolantes 8 et leur largeur représente, par exemple, 20 à 60% de la largeur des bandes 8.According to this first embodiment of the invention, additional conductive strips 19 are deposited on the insulating strips 8 separating two strips of phosphor elements neighbors. According to the present invention, the width of the strips additional 19 is less than the space separating two bands neighboring phosphor elements and therefore does not entirely cover the insulating strips 8. The strips 19 are substantially centered on the insulating strips 8 and their width represents, for for example, 20 to 60% of the width of the strips 8.

    Selon l'invention, les bandes 19 sont polarisées à un potentiel au plus égal au potentiel minimal de polarisation de la cathode afin de créer un champ électrique repoussant les électrons émis par les micropointes (non représentées). Les bandes 19 ont alors un effet de focalisation des électrons émis par la cathode vers les bandes 9 portant les éléments luminophores. Ainsi, on minimise la proportion d'électrons susceptibles de bombarder la couche d'isolement 8 subsistant entre les bandes 19 et les éléments luminophores 7 et, par voie de conséquence, l'accumulation de charges négatives en surface de cette couche 8. De plus, même si quelques électrons parviennent à atteindre les parties 18 accessibles de la couche 8 de part et d'autre des bandes 19, l'énergie de ces électrons est extrêmement faible (proche de 0 électron-volt) et ces électrons sont alors incapables de provoquer l'émission d'électrons secondaires.According to the invention, the bands 19 are polarized at a potential at most equal to the minimum potential for polarization of the cathode to create an electric field repelling electrons emitted by microtips (not shown). The bands 19 then have a focusing effect of the electrons emitted by the cathode to the bands 9 carrying the phosphor elements. Thus, we minimize the proportion of electrons likely to bombard the insulation layer 8 remaining between the strips 19 and the phosphor elements 7 and, consequently, the accumulation of negative charges on the surface of this layer 8. Of more, even if some electrons manage to reach the parts 18 accessible from layer 8 on either side of the bands 19, the energy of these electrons is extremely low (close to 0 electron volts) and these electrons are then unable to cause the emission of secondary electrons.

    Un avantage de ce mode de réalisation est que les parties 18 d'isolant subsistant de part et d'autre de chaque bande 19 assurent l'isolement entre ces bandes conductrices additionnelles et les bandes d'éléments luminophores sans qu'il soit nécessaire d'augmenter l'épaisseur des bandes isolantes 8. Ainsi, selon la présente invention, les bandes isolantes 8 présentent une épaisseur conforme aux précédés classiques de réalisation d'une anode d'écran plat, par exemple, comprise entre 1 et 5 µm.An advantage of this embodiment is that the parts 18 of insulation remaining on each side of each strip 19 provide insulation between these additional conductive strips and strips of phosphor elements without it necessary to increase the thickness of the insulating strips 8. Thus, according to the present invention, the insulating strips 8 have a thickness in accordance with the conventional precedents of realization a flat screen anode, for example, between 1 and 5 μm.

    Un autre avantage par rapport à la technique connue du document EP-A-0635865 est que les défauts d'alignement entre le masque de dépôt par sérigraphie des éléments luminophores par rapport au motif de gravure de la couche 8 n'est pas gênant. En effet, les débordements éventuels des éléments luminophores sont ici déposés sur les parties isolantes 18. L'épaisseur des bandes d'éléments luminophores est généralement de l'ordre de 10 µm.Another advantage compared to the known technique of EP-A-0635865 is that the misalignments between the deposition mask by screen printing of the phosphor elements by compared to the etching pattern of layer 8 is not a problem. In Indeed, the possible overflows of the phosphor elements are here deposited on the insulating parts 18. The thickness of the strips of phosphor elements is generally of the order of 10 μm.

    Les figures 3 et 4 représentent, respectivement en coupe et en vue de dessous, un deuxième mode de réalisation d'une anode d'écran plat couleur selon la présente invention. A la figure 4, les éléments luminophores n'ont pas été représentés.Figures 3 and 4 show respectively in section and seen from below, a second embodiment of a color flat screen anode according to the present invention. To the Figure 4, the phosphor elements have not been shown.

    Une caractéristique de ce mode de réalisation est de prévoir, entre deux bandes conductrices 9 voisines portant des éléments luminophores, une bande conductrice additionnelle 29, revêtue de la couche isolante 8 séparant les bandes 9 les unes des autres.A feature of this embodiment is provide between two neighboring conductive strips 9 carrying phosphor elements, an additional conductive strip 29, coated with insulating layer 8 separating the strips 9 together others.

    Comme pour le premier mode de réalisation, ces bandes 29 sont polarisées à un potentiel au plus égal au potentiel minimal de polarisation de la cathode, afin de créer un champ électrique repoussant les électrons émis par les micropointes.As for the first embodiment, these bands 29 are polarized at a potential at most equal to the minimum potential cathode polarization to create an electric field repelling the electrons emitted by the microtips.

    Les bandes 29 sont sensiblement centrées entre deux bandes 9 voisines et présentent, de préférence, une largeur comprise entre 20 et 90% de l'écart entre deux bandes voisines. Les bandes focalisatrices 29 peuvent être plus larges que dans le premier mode de réalisation. L'écart entre une bande 29 et une bande 9 est en effet uniquement lié au besoin d'isolement entre ces bandes et n'a pas besoin de garantir l'isolement en cas de débordement des éléments luminophores. Plus les bandes focalisatrices sont larges, plus l'effet focalisateur est important pour un potentiel donné.The bands 29 are substantially centered between two neighboring bands 9 and preferably have a width comprised between 20 and 90% of the difference between two neighboring bands. The focusing strips 29 can be wider than in the first embodiment. The gap between a strip 29 and a band 9 is in fact only linked to the need for isolation between these tapes and need not guarantee isolation in the event of overflow of phosphor elements. Plus the focusing strips are large, the greater the focusing effect for a given potential.

    A titre d'exemple particulier de réalisation, la largeur des bandes 9 de conducteurs d'anode est de l'ordre de 80 µm et l'écart entre deux bandes voisines de conducteurs d'anode est de l'ordre de 40 µm.As a particular embodiment, the width strips 9 of anode conductors is of the order of 80 μm and the gap between two neighboring strips of anode conductors is on the order of 40 µm.

    De préférence, les bandes 29 sont constituées du même matériau (par exemple de l'ITO) que les bandes 9 portant les éléments luminophores. Un avantage d'un tel mode de réalisation est que la réalisation d'une anode selon l'invention ne nécessite alors aucune étape supplémentaire par rapport à un précédé classique de fabrication d'une anode d'écran plat.Preferably, the bands 29 are made of the same material (eg ITO) that the bands 9 carrying the elements phosphors. An advantage of such an embodiment is that the production of an anode according to the invention does not require then no additional step compared to a traditional precedent for manufacturing a flat screen anode.

    En effet, comme les bandes conductrices 29 de focalisation sont enterrées dans la couche d'isolement 8, il suffit de modifier le masque de définition des bandes 9 de conducteurs d'anode pour forme en même temps les bandes focalisatrices 29.Indeed, like the focusing conductive strips 29 are buried in the isolation layer 8, just modify the mask for defining the bands of 9 conductors anode to form the focusing strips 29 at the same time.

    De même, l'interconnexion des bandes 29 pour permettre leur polarisation peut alors être effectuée en même temps que sont réalisées les interconnexions des bandes 9 par ensemble de bandes de même couleur.Likewise, the interconnection of bands 29 to allow their polarization can then be carried out at the same time as the interconnections of the bands 9 are made by set of bands of the same color.

    On pourra, par exemple, utiliser un procédé de fabrication tel que décrit dans le document FR-A-2 735 254, dont le contenu sera considéré comme faisant partie de la présente description.We could, for example, use a manufacturing process as described in document FR-A-2 735 254, the content will be considered part of this description.

    En utilisant ce procédé qui consiste à réaliser l'interconnexion de deux ensembles de bandes conductrices de l'anode, sur un premier niveau, puis l'interconnexion du troisième ensemble sur un deuxième niveau, l'interconnexion des bandes 29 s'effectue sur le deuxième niveau. By using this process which consists in carrying out the interconnection of two sets of conductive strips of the anode, on a first level, then the interconnection of the third together on a second level, the interconnection of the bands 29 takes place on the second level.

    Les figures 5A et 5B illustrent, par des vues en coupe, prises respectivement selon les lignes A-A et B-B de la figure 4, les interconnexions des bandes 9 et 29 à leurs extrémités.FIGS. 5A and 5B illustrate, in sectional views, taken respectively along lines A-A and B-B of FIG. 4, the interconnections of bands 9 and 29 at their ends.

    On réalise, en même temps que les bandes 9 et 29, deux pistes 11 et 12 d'interconnexion des bandes 9r et 9b, une première série de plots 13 (figure 4) à des premières extrémités des bandes 9g, et une deuxième série de plots 14 à des deuxièmes extrémités des bandes 29.We realize, at the same time as bands 9 and 29, two tracks 11 and 12 for interconnecting bands 9r and 9b, one first series of studs 13 (FIG. 4) at the first ends bands 9g, and a second series of studs 14 to second ends of the bands 29.

    Puis, on dépose la couche d'isolement 8 et on grave cette couche selon le motif de dépôt en bandes 7 des éléments luminophores au droit des bandes 9 dans la zone active de l'écran, ainsi que selon le motif des plots 13 et 14. La couche 8 est également ouverte pour créer deux plots 15 et 16 (figures 5A et 5B) de raccordement des pistes 11 et 12.Then, we put the isolation layer 8 and etch this layer according to the pattern of deposition in bands 7 of the elements phosphors to the right of bands 9 in the active area of the screen, as well as according to the pattern of the studs 13 and 14. The layer 8 is also open to create two pads 15 and 16 (Figures 5A and 5B) connecting tracks 11 and 12.

    Les ouvertures réalisées aux droits des plots 13, 14 et 15, 16 sont remplies d'un matériau conducteur pour reporter les contacts au-dessus de la couche 8.The openings made at the rights of studs 13, 14 and 15, 16 are filled with a conductive material to transfer the contacts above layer 8.

    On dépose alors une couche conductrice que l'on grave selon le motif de deux pistes d'interconnexion 20 et 21 des plots 13 et des plots 14, et selon le motif des plots 15 et 16 pour créer des plots 21 et 22 de raccordement des pistes 11 et 12.We then deposit a conductive layer which we etch according to the pattern of two interconnection tracks 20 and 21 of the pads 13 and studs 14, and according to the pattern of studs 15 and 16 for create pads 21 and 22 for connecting tracks 11 and 12.

    Un avantage de la présente invention est que la structure prévue est parfaitement compatible avec les étapes d'un procédé classique de fabrication d'une anode d'écran plat.An advantage of the present invention is that the structure planned is perfectly compatible with the steps of a process conventional manufacturing of a flat screen anode.

    Pour un écran plat couleur à micropointes dont la grille est polarisée à un potentiel d'environ 80 volts et dont les micropointes sont polarisées entre 0 volt (émission maximale) et 30 volts (absence d'émission), les bandes 19 ou 29 sont, par exemple, polarisées à un potentiel épris entre 0 et -200 volts.For a color microtip flat screen whose grid is polarized at a potential of about 80 volts and of which the microtips are polarized between 0 volts (maximum emission) and 30 volts (no emission), bands 19 or 29 are, for example, polarized at a potential loving between 0 and -200 volts.

    Plus le potentiel de polarisation des bandes focalisatrices est inférieur au potentiel minimal de polarisation de la cathode, plus l'effet focalisateur est important. Ainsi, en choisissant un potentiel suffisamment négatif, on constate que tous les électrons sont repoussés de l'intervalle séparant deux bandes d'éléments luminophores. The higher the polarization potential of the focusing bands is less than the minimum potential for polarization of the cathode, the greater the focusing effect. So, by choosing sufficiently negative potential, we see that all electrons are pushed back from the gap between two bands phosphor elements.

    Un avantage de la présente invention est qu'elle supprime le phénomène de dérive de couleur constaté sur les écrans classiques.An advantage of the present invention is that it eliminates the phenomenon of color drift observed on the screens classics.

    Un autre avantage de la présente invention est qu'elle améliore considérablement la durée de vie de l'écran en supprimant tous risque d'arcage entre deux bandes d'éléments luminophores voisines.Another advantage of the present invention is that it dramatically improves screen life by removing all risk of arcing between two strips of phosphor elements neighbors.

    On notera que l'invention s'applique également à un écran monochrome dans lequel les éléments luminophores de l'anode sont portés par des électrodes d'anode organisées en deux ensembles de bandes alternées d'éléments luminophores de même couleur. Dans ce cas, l'invention améliore encore la résolution de l'écran qui est déjà meilleure que celle d'un écran dont l'anode est constituée d'un plan d'éléments luminophores de même couleur.It will be noted that the invention also applies to a monochrome screen in which the phosphor elements of the anode are carried by anode electrodes organized in two sets alternating bands of phosphor elements of the same color. In this case, the invention further improves the resolution of the screen which is already better than that of a screen whose anode is consisting of a plan of phosphor elements of the same color.

    Bien entendu, la présente invention est susceptible de diverses variantes et modifications qui apparaítront à l'homme de l'art. En particulier, le potentiel de polarisation des bandes de focalisation et leur largeur pourront être modifiés en fonction du type d'écran et des potentiels de polarisation de ses constituants.Of course, the present invention is capable of various variants and modifications which will appear to the man of art. In particular, the polarization potential of the focus and width can be changed depending the type of screen and the polarization potentials of its constituents.

    Claims (10)

    Anode (5') d'écran plat de visualisation du type comportant au moins deux ensembles de bandes (9) parallèles alternées de conducteurs d'anode revêtues d'éléments luminophores (7), séparées les unes des autres par des bandes d'isolement (8) et polarisables à des potentiels différents en fonction des éléments luminophores à exciter, caractérisée en ce qu'elle comporte des bandes conductrices (19, 29) de focalisation, alignées et sensiblement centrées avec les bandes d'isolement, les bandes conductrices de focalisation ayant des largeurs inférieures à celles des bandes d'isolement.Type 5 flat screen display anode comprising at least two sets of parallel strips (9) alternating anode conductors coated with phosphor elements (7), separated from each other by insulation strips (8) and polarizable at different potentials depending on the elements phosphors to be excited, characterized in that it comprises conducting conductive strips (19, 29), aligned and substantially centered with the insulation bands, the bands focusing conductors having widths less than those of the isolation bands. Anode selon la revendication 1, caractérisée en ce que les bandes de focalisation (19, 29) sont polarisées à un potentiel négatif ou nul.Anode according to claim 1, characterized in that that the focusing bands (19, 29) are polarized at a negative or zero potential. Anode selon la revendication 1 ou 2, caractérisée en ce que l'épaisseur des bandes d'isolement (8) est comprise entre 1 et 5 µm.Anode according to claim 1 or 2, characterized in that the thickness of the insulation strips (8) is between 1 and 5 µm. Anode selon l'une quelconque des revendications 1 à 3, caractérisée en ce que les bandes de focalisation (19) sont déposées sur les bandes d'isolement (8).Anode according to any one of claims 1 to 3, characterized in that the focusing strips (19) are deposited on the insulation strips (8). Anode selon la revendication 4, caractérisée en ce que la largeur des bandes conductrices de focalisation (19) représente entre 20 et 60% de la largeur des bandes d'isolement (8).Anode according to claim 4, characterized in that that the width of the focusing conductive strips (19) represents between 20 and 60% of the width of the insulation strips (8). Anode selon l'une quelconque des revendications 1 à 3, caractérisée en ce que les bandes de focalisation (29) sont enterrées dans les bandes d'isolement (8).Anode according to any one of claims 1 to 3, characterized in that the focusing strips (29) are buried in the isolation strips (8). Anode selon la revendication 6, caractérisée en ce que l'écart entre une bande de focalisation (29) et une bande voisine de conducteur d'anode (9) est choisi pour supporter une différence de potentiel déterminée entre ces deux bandes voisines, la largeur des bandes conductrices de focalisation représentant, de préférence, 20 à 90% de l'écart entre des bandes (9) voisines de conducteurs d'anode. Anode according to claim 6, characterized in that that the gap between a focusing strip (29) and a strip neighbor of anode conductor (9) is chosen to support a determined potential difference between these two neighboring bands, the width of the focusing conductive strips representing, preferably 20 to 90% of the gap between bands (9) neighbors of anode conductors. Anode selon la revendication 6 ou 7, caractérisée en ce que les bandes de focalisation (29) sont constituées du même matériau que les bandes (9) de conducteurs d'anode.Anode according to claim 6 or 7, characterized in that the focusing strips (29) consist of the same material as the strips (9) of anode conductors. Procédé de réalisation d'une anode d'écran plat de visualisation selon la revendication 8, caractérisé en ce que le masque de définition des bandes (9) de conducteurs d'anode définit également le motif des bandes conductrices de focalisation (29).Method for producing a flat screen anode of display according to claim 8, characterized in that the anode conductor strip definition mask (9) also defines the pattern of the focusing conductive strips (29). Écran plat de visualisation du type comportant une cathode (1) à micropointes (2) et une anode (5') constituée d'au moins deux ensembles de bandes alternées d'éléments luminophores (7), caractérisé en ce que ladite anode comporte des bandes focalisatrices (19, 29) selon l'une quelconque des revendications 1 à 8.Flat display screen of the type comprising a cathode (1) with microtips (2) and an anode (5 ') consisting of at least two sets of alternating bands of phosphor elements (7), characterized in that said anode has focusing strips (19, 29) according to any one of claims 1 to 8.
    EP98410045A 1997-04-30 1998-04-29 Anode of a flat display screen Pending EP0877407A1 (en)

    Applications Claiming Priority (2)

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    FR9705601A FR2762927A1 (en) 1997-04-30 1997-04-30 FLAT DISPLAY ANODE
    FR9705601 1997-04-30

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    KR100499120B1 (en) * 2000-02-25 2005-07-04 삼성에스디아이 주식회사 Triode structure field emission display using carbon nanotube
    US6509696B2 (en) 2001-03-22 2003-01-21 Koninklijke Philips Electronics N.V. Method and system for driving a capacitively coupled fluorescent lamp
    EP1897112A1 (en) * 2005-06-30 2008-03-12 Thomson Licensing Segmented conductive coating for a luminescent display device

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