EP1956625B1 - Field-effect electron emission structure with emission focussing - Google Patents
Field-effect electron emission structure with emission focussing Download PDFInfo
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- EP1956625B1 EP1956625B1 EP08101232A EP08101232A EP1956625B1 EP 1956625 B1 EP1956625 B1 EP 1956625B1 EP 08101232 A EP08101232 A EP 08101232A EP 08101232 A EP08101232 A EP 08101232A EP 1956625 B1 EP1956625 B1 EP 1956625B1
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- European Patent Office
- Prior art keywords
- electron emitting
- gate electrode
- bands
- emitting elements
- emission zone
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Images
Classifications
-
- 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
- H01J29/58—Arrangements for focusing or reflecting ray or beam
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J2329/00—Electron emission display panels, e.g. field emission display panels
Definitions
- the invention relates to an electron emitting structure for a field effect device. It concerns the focus of the electronic program.
- the document FR-A-2,836,279 discloses a cathode structure for an emissive screen.
- the cathode structure is of the triode type, that is to say that it comprises an electron extraction grid.
- the grid is an electrode provided with openings.
- the electron emitting elements are located in the central part of each gate opening. This structure is well suited to the use of nanotubes as electron emitting elements.
- the figure 1 is a perspective view and very partial of a cathode structure disclosed by the document FR-A-2,836,279 .
- the cathode structure comprises a substrate 1, for example made of glass, successively supporting a cathode electrode 3, a resistive layer 2, a dielectric layer 4 and an extraction gate electrode 5.
- An opening 6 formed in the gate electrode 5 and the dielectric layer 4 reveals the resistive layer 2 which supports electron emitting elements 7 in carbon nanotubes.
- the emitting elements are placed symmetrically with respect to the two parts of the gate electrode 5 so that the lateral component of the electric field, which is one of the causes of the divergence of the electron beam, is minimal.
- the figure 2 is a top view of the structure of an image element (or pixel) made according to the teaching of the document FR-A-2,836,279 .
- the figure 1 is a view corresponding to section II of the figure 2 .
- the figure 2 shows the gate electrode 5 provided with slots 6 revealing electron emitting elements 7 supported by the resistive layer 2.
- a cathode electrode 3 has also been initiated, although not visible in plan view.
- Reference 8 represents the shape of the electronic spot (or spot) coming from an electron emitting element 7.
- the document FR-A-2,873,852 proposed an improvement of the teaching of the document FR-A-2,836,279 .
- This improvement consists in rotating the slots of the gate electrode by 90 ° so that these slots are perpendicular to the red-green-blue bands of the phosphors disposed on an anode facing the cathode structure. The slots are therefore arranged perpendicularly to the columns formed by the cathode electrodes.
- the figure 3 shows three pixels of a cathode structure according to the teaching of the document FR-A-2,873,852 .
- the pixels represented result from the crossing of cathode electrodes 13 and gate electrodes 15.
- the slots 16 of the gate electrodes are arranged perpendicularly to the cathode electrodes 13.
- the references 18 designate electronic spots coming from transmission elements. Electrons 17. It is seen that the interline mixing of the electron beams is important. Nevertheless, with this structure, there remains a significant divergence along the Y axis, a divergence that results in a loss of useful electrons for the pixel and in random pixel-to-pixel brightness fluctuations. These fluctuations come from a mixture of the electrons coming from the neighboring pixels of the pixel of interest (see figure 3 ).
- the object of the present invention is to minimize this problem.
- the subject of the invention is a field-emitting and triode-type electron-emitting structure comprising at least one electron emission zone resulting from the crossing of a cathode electrode arranged along a first axis and a extraction grid disposed along a second axis, a layer of electrical insulation separating the cathode electrode of the gate electrode, the electron emission zone comprising a plurality of electron emitting elements electrically connected to the cathode electrode, the electron emitting elements being arranged in rows in openings formed in the gate electrode and the electrical insulator layer, the gate openings being arranged in rows, each gate opening being between two bands of the gate electrode, the structure also comprising means for focusing the beams.
- the focusing means are constituted by an asymmetrical arrangement of rows of electron emitting elements and their adjacent gate electrode strips, the dissymmetry being organized to focus the set of electron beams and resulting from a difference in bandwidth of the gate electrode adjacent to the same gate aperture so that for that gate aperture, the adjacent outermost band of the electron emission zone is narrower than the nearest-most adjacent band. inside the electronic emission zone.
- the difference in width of the electrode strips may be such that the width of the bands decreases progressively from the inside to the outside of the electron emission zone.
- the gate electrode may have, in the central part of the electronic emission zone, at least one gate opening whose adjacent bands are equal. widths, the electrode strips of gradually decreasing width being located on either side of this central portion.
- the asymmetry also results from an offset of at least one row of electron-emitting elements with respect to the main axis of the gate opening corresponding to this row. , the offset consisting in bringing said row closer to the center of the electronic emission zone. Since the dissymmetry resulting from the shifting of several rows of electron-emitting elements, the shift may progressively increase from the inside to the outside of the electron emission zone.
- the gate electrode may have, in the central part of the electronic emission zone, at least one gate opening whose row of electron-emitting elements is centered on its main axis, the rows of emitting elements progressively increasing shift electrons being located on either side of this central part.
- the bands of the gate electrode may be oriented along the first axis or along the second axis.
- the invention will be explained by comparing a triode type electron-emitting structure according to the prior art, illustrated by FIG. figure 4 , and a triode type electron-emitting structure, used by the invention and illustrated by the figure 5 .
- the figure 4 shows a cathode electrode 23 successively supporting a dielectric layer 24 and a gate electrode 25.
- An opening 26 is made in the gate electrode 25 and the dielectric layer 24 to reveal the cathode electrode 23.
- an electron-emitting element 27 In the center of the 26 and in electrical contact with the cathode electrode 23 is disposed an electron-emitting element 27.
- the electron-emitting element can be in electrical contact with the cathode electrode by means of a resistive layer ( or ballast layer) as in the case illustrated by the figure 1 .
- the opening 26 separates the gate electrode 25 into two parts (left and right of the line) electrically connected to each other.
- Arrows show the horizontal (along the Y axis) and the vertical (Z axis) electric field components that are generated when the cathode structure is operating.
- Electronic trajectories have also been represented under the reference 20.
- the structure being symmetrical (emitter element located in the center of the opening, left and right parts of the gate electrode of the same width), the zone where the electric field is vertical corresponds to the center of the emitter element.
- the electrons emitted on either side of the vertical field line diverge in the same way on both sides of the vertical field line.
- the figure 5 shows a cathode structure virtually identical to that of the figure 4 : cathode electrode 33, dielectric layer 34, gate electrode 35, aperture 36 and electron emitter element 37.
- An essential difference concerns the asymmetry of width existing between the left and right parts of the gate electrode 35. case of figure 5 , the right part of the gate electrode is wider than the left part.
- the figure 6 is a top view of a pixel according to the first embodiment of the invention.
- a cathode electrode 43 and an extraction gate electrode 45 provided with slots 46 in the form of slots.
- Each slot 46 reveals a row of electron emitting elements 47 electrically connected to the cathode electrode 43 via a resistive layer (or ballast layer) 42.
- the slots 46 are separated from each other by strips 49.
- the structure of the pixel defined by the intersection of the cathode electrode 43 and the gate electrode 45 has as a line of symmetry the line AA 'directed along the axis of the gate electrode. Note on this structure that the widths of the bands 49 are becoming weaker as one moves away from the line AA '.
- the reference 48 designates electronic spots coming from electron-emitting elements 47.
- the electronic spot 48 coming from an electron-emitting element 47 situated on the axis AA ' is centered on this element since there exists a symmetry at level of the axis AA 'between the electron emitting elements and the adjacent bands 49 which are of the same width.
- the electronic spots 48 coming from electron emitting elements 47 situated in slots 46 not centered on the axis AA ' are eccentric because of the smaller width of the strips 49 furthest away from the axis AA'. The eccentricity of these spots causes the focus of all the electronic spots from the pixel.
- the structure of a pixel usually has a much higher number of grid electrode strips.
- a bandwidth gradient is made along the Y axis (see FIG. figure 6 ), starting from the central figure of the pixel constituted by the axis AA 'when the gate electrode strips are oriented along the axis X (axis of the gate electrode).
- the gate electrode strips are oriented along the Y axis (as shown in FIG. figure 2 , Y being the axis of the cathode electrode)
- a bandwidth gradient will be realized along the X axis (axis of the gate electrode).
- the figure 7 gives an example of the width profile L of the bands of a grid electrode along the Y axis for a pixel of a display screen.
- the y-axis, representing the width L is positioned on the center line of the pixel.
- there is a first area where the gate electrode bands are of constant width up to a distance Y 0 from the center line which substantially corresponds to (h / 2 - d) where h is a dimension of the pixel corresponding to a gate electrode, d is the overflow of the electron beam, with d g.tg ⁇ , where g is the distance separating the anode from the cathode of the display screen and ⁇ is the half-divergence of the beam electronic.
- the gradient remains up to the value Y 1 representing the edge of the emissive zone of the pixel.
- the decentering consisting of to bring the rows of emitting elements closer to the strip closest to the axis AA '.
- the bands 49 are of equal widths and, when one moves away from the axis AA ', the rows of electron-emitting elements are decentered more and more towards the axis AA'.
- the figure 9 illustrates an exemplary implementation of the invention for a color flat screen display pixel.
- the pixel has three subpixels: a subpixel for the red color, a subpixel for the green color and a subpixel for the blue color.
- a subpixel for the red color a subpixel for the red color
- a subpixel for the green color a subpixel for the blue color.
- connections 90 electrically connect the three sub-pixels.
- the connections 90 are arranged along the central axis AA 'of the pixel to avoid the creation of divergent lateral electric fields.
- the sub-pixels 100, 200 and 300 being identical, only the sub-pixel 300 will be described in more detail.
- a sub-pixel such as the sub-pixel 300 comprises four identical parts arranged symmetrically with respect to the center of the sub-pixel 300 1 , 300 2 , 300 3 and 300 4 .
- the figure 10 shows one of the four portions 300 4 of the sub-pixel 300.
- the portion 300 4 consists of the electrode strip 90 (common to the part 300 2 ) and successive electrode strips 91 to 99.
- the width of the strips is in accordance with the profile illustrated by the figure 7 .
- the strips 90 to 94 have a width of 13 ⁇ m
- the strip 95 has a width of 11 ⁇ m
- the strip 96 has a width of 9 ⁇ m
- the strip 97 has a width of 7 ⁇ m
- the strip 98 has a width of 5 ⁇ m
- the band 99 has a width of 3 ⁇ m.
- the rows of electron emitting elements 80 are arranged symmetrically between two adjacent bands. The distance separating two adjacent strips is, for example, 12 ⁇ m.
- FIGS. 11A to 11D are cross-sectional views illustrating an embodiment of the present invention.
- the figure 11A shows a substrate 51, for example glass, on which are deposited and etched cathode conductors 53 which may be molybdenum or tungsten alloy and titanium and which represent the columns of the screen.
- cathode conductors 53 which may be molybdenum or tungsten alloy and titanium and which represent the columns of the screen.
- a layer 52 of amorphous silicon having a thickness of between 0.5 and 2 ⁇ m, an electrically insulating layer 54 of silica with a thickness of between 1 and 3 ⁇ m and a metal layer 55 of molybdenum or copper are then successively deposited. , intended to form the electron extraction grid.
- a resin layer 60 is then deposited on the structure obtained. Openings are made in the resin to define the lines of the screen and the grid patterns. Thus, an opening 61 defines the size of the future electron emitting elements.
- the metal layer 55 and the electrical insulating layer 54 are etched by reactive dry etching (see FIG. Figure 11B ).
- a pad 62 is deposited consisting of a catalyst layer (typically iron, nickel or iron / silicon / palladium / nickel alloys in thickness of 1 to 20 nm).
- the pad may also be a multilayer comprising a metal sub-layer (TiN, TaN, Al or Ti 50 nm thick) and a catalyst layer.
- the figure 11D shows the structure obtained after removal of the resin followed by the growth of carbon nanotubes 63 by CVD using a pressure of some 0.1 mbar acetylene at 550 ° C for 1 minute.
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- Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
- Cold Cathode And The Manufacture (AREA)
Description
L'invention se rapporte à une structure émettrice d'électrons pour dispositif à effet de champ. Elle concerne la focalisation de l'émission électronique.The invention relates to an electron emitting structure for a field effect device. It concerns the focus of the electronic program.
La divergence des faisceaux électroniques est un critère de qualité important pour les écrans à émission de champ. En effet, cette divergence contrôle la résolution des écrans réalisables, la pureté des couleurs, le rendement lumineux et également l'uniformité de l'émission.Divergence of electron beams is an important quality criterion for field emission screens. Indeed, this divergence controls the resolution of achievable screens, the purity of colors, the light output and also the uniformity of the emission.
Le document
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La
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La dissymétrie de la structure en X et Y fait que la divergence est plus faible selon l'axe des fentes 6 que selon l'axe X perpendiculaire aux fentes. La référence 8 représente la forme de la tache (ou spot) électronique issu d'un élément émetteur d'électrons 7.The asymmetry of the structure in X and Y makes the divergence is smaller along the axis of the
Le document
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L'objectif de la présente invention est de minimiser ce problème.The object of the present invention is to minimize this problem.
L'invention a pour objet une structure émettrice d'électrons par effet de champ et de type triode, comprenant au moins une zone d'émission électronique résultant du croisement d'une électrode de cathode disposée selon un premier axe et d'une électrode de grille d'extraction disposée selon un deuxième axe, une couche d'isolant électrique séparant l'électrode de cathode de l'électrode de grille, la zone d'émission électronique comprenant une pluralité d'éléments émetteurs d'électrons électriquement connectés à l'électrode de cathode, les éléments émetteurs d'électrons étant disposés en rangées dans des ouvertures pratiquées dans l'électrode de grille et la couche d'isolant électrique, les ouvertures de grille étant disposées en rangées, chaque ouverture de grille étant comprise entre deux bandes de l'électrode de grille, la structure comprenant également des moyens de focalisation des faisceaux électroniques émis par les éléments émetteurs d'électrons, caractérisée en ce que les moyens de focalisation sont constitués par une disposition dissymétrique de rangées d'éléments émetteurs d'électrons et de leurs bandes d'électrode de grille adjacentes, la dissymétrie étant organisée pour focaliser l'ensemble des faisceaux électroniques et résultant d'une différence de largeur de bandes d'électrode de grille adjacentes à une même ouverture de grille de façon que, pour cette ouverture de grille, la bande adjacente située la plus vers l'extérieur de la zone d'émission électronique est moins large que la bande adjacente située le plus vers l'intérieur de la zone d'émission électronique.The subject of the invention is a field-emitting and triode-type electron-emitting structure comprising at least one electron emission zone resulting from the crossing of a cathode electrode arranged along a first axis and a extraction grid disposed along a second axis, a layer of electrical insulation separating the cathode electrode of the gate electrode, the electron emission zone comprising a plurality of electron emitting elements electrically connected to the cathode electrode, the electron emitting elements being arranged in rows in openings formed in the gate electrode and the electrical insulator layer, the gate openings being arranged in rows, each gate opening being between two bands of the gate electrode, the structure also comprising means for focusing the beams. electronics emitted by the electron emitting elements, characterized in that the focusing means are constituted by an asymmetrical arrangement of rows of electron emitting elements and their adjacent gate electrode strips, the dissymmetry being organized to focus the set of electron beams and resulting from a difference in bandwidth of the gate electrode adjacent to the same gate aperture so that for that gate aperture, the adjacent outermost band of the electron emission zone is narrower than the nearest-most adjacent band. inside the electronic emission zone.
La différence de largeur des bandes d'électrode peut être telle que la largeur des bandes décroît progressivement de l'intérieur vers l'extérieur de la zone d'émission électronique. L'électrode de grille peut présenter, en partie centrale de la zone d'émission électronique, au moins une ouverture de grille dont les bandes adjacentes sont d'égales largeurs, les bandes d'électrode de largeur progressivement décroissante étant situées de part et d'autre de cette partie centrale.The difference in width of the electrode strips may be such that the width of the bands decreases progressively from the inside to the outside of the electron emission zone. The gate electrode may have, in the central part of the electronic emission zone, at least one gate opening whose adjacent bands are equal. widths, the electrode strips of gradually decreasing width being located on either side of this central portion.
Selon un mode de mise en oeuvre de l'invention, la dissymétrie résulte aussi d'un décalage d'au moins une rangée d'éléments émetteurs d'électrons par rapport à l'axe principal de l'ouverture de grille correspondant à cette rangée, le décalage consistant à rapprocher ladite rangée du centre de la zone d'émission électronique. La dissymétrie résultant du décalage de plusieurs rangées d'éléments émetteurs d'électrons, le décalage peut augmenter progressivement de l'intérieur vers l'extérieur de la zone d'émission électronique. Ainsi, l'électrode de grille peut présenter, en partie centrale de la zone d'émission électronique, au moins une ouverture de grille dont la rangée d'éléments émetteurs d'électrons est centrée sur son axe principal, les rangées d'éléments émetteurs d'électrons à décalage augmentant progressivement étant situées de part et d'autre de cette partie centrale.According to an embodiment of the invention, the asymmetry also results from an offset of at least one row of electron-emitting elements with respect to the main axis of the gate opening corresponding to this row. , the offset consisting in bringing said row closer to the center of the electronic emission zone. Since the dissymmetry resulting from the shifting of several rows of electron-emitting elements, the shift may progressively increase from the inside to the outside of the electron emission zone. Thus, the gate electrode may have, in the central part of the electronic emission zone, at least one gate opening whose row of electron-emitting elements is centered on its main axis, the rows of emitting elements progressively increasing shift electrons being located on either side of this central part.
Les bandes de l'électrode de grille peuvent être orientées selon le premier axe ou selon le deuxième axe.The bands of the gate electrode may be oriented along the first axis or along the second axis.
L'invention sera mieux comprise et d'autres avantages et particularités apparaîtront à la lecture de la description qui va suivre, donnée à titre d'exemple non limitatif, accompagnée des dessins annexés parmi lesquels :
- la figue 1 est une vue en perspective et très partielle d'une structure de cathode de type triode selon l'art antérieur,
- la
figure 2 est une vue de dessus de la structure d'un élément d'image pour écran de visualisation, selon l'art antérieur, - la
figure 3 est une vue de dessus de trois éléments d'image d'une structure de cathode selon l'art antérieur, ainsi que des spots électroniques issus d'éléments émetteurs d'électrons de ces éléments d' image, - la
figure 4 représente de manière schématique une structure émettrice d'électrons, de type triode, selon l'art antérieur, - la
figure 5 représente de manière schématique une structure émettrice d'électrons, de type triode, faisant partie d'un élément d'image à multiple éléments émetteurs d'électrons, - la
figure 6 est une vue de dessus d'un pixel selon un premier mode de mise en oeuvre de l'invention, - la
figure 7 est un diagramme montrant un exemple de profil de largeur des bandes d'une électrode de grille d'extraction suivant l'axe Y d'un pixel, selon l'invention, - la
figure 8 est une vue de dessus d'un pixel selon un deuxième mode de mise en oeuvre de l'invention, - la
figure 9 est une vue de dessus d'un pixel couleur d'écran plat de visualisation selon l'invention, - la
figure 10 est une vue partielle du pixel de lafigure 9 , - les
figures 11A à 11D sont des vues en coupe transversale illustrant un mode de réalisation de la présente invention.
- FIG. 1 is a perspective and very partial view of a cathode structure of the triode type according to the prior art,
- the
figure 2 is a top view of the structure of an image element for a display screen, according to the prior art, - the
figure 3 is a top view of three image elements of a cathode structure according to the prior art, as well as electronic spots emanating from electron emitting elements of these image elements, - the
figure 4 schematically represents an electron-emitting structure, of the triode type, according to the prior art, - the
figure 5 schematically represents a triode-type electron-emitting structure forming part of a multi-electron emitting element image element, - the
figure 6 is a top view of a pixel according to a first embodiment of the invention, - the
figure 7 is a diagram showing an example of band width profile of a Y-axis extraction grid electrode of a pixel, according to the invention, - the
figure 8 is a top view of a pixel according to a second embodiment of the invention, - the
figure 9 is a top view of a color pixel flat display screen according to the invention, - the
figure 10 is a partial view of the pixel of thefigure 9 , - the
Figures 11A to 11D are cross-sectional views illustrating an embodiment of the present invention.
L'invention va être expliquée en comparant une structure émettrice d'électrons de type triode selon l'art antérieur, illustrée par la
La
On a représenté par des flèches les composantes de champ électrique horizontales (selon l'axe Y) et verticales (selon l'axe Z) qui sont générées lorsque la structure de cathode fonctionne. On a également représenté sous la référence 20 des trajectoires électroniques. La structure étant symétrique (élément émetteur situé au centre de l'ouverture, parties gauche et droite de l'électrode de grille de même largeur), la zone où le champ électrique est vertical correspond au centre de l'élément émetteur. Les électrons émis de part et d'autre de la ligne de champ verticale divergent de la même manière de part et d'autre de la ligne de champ verticale.Arrows show the horizontal (along the Y axis) and the vertical (Z axis) electric field components that are generated when the cathode structure is operating. Electronic trajectories have also been represented under the
La
Il résulte de cette dissymétrie que la ligne de champ vertical ne se situe plus au centre de l'élément émetteur d'électrons. Cette ligne est décalée du côté de la partie de l'électrode de grille la plus étroite. Les électrodes ont alors des trajectoires 30 qui sont essentiellement dirigées du côté opposé à la partie de l'électrode de grille la plus étroite.It follows from this dissymmetry that the vertical field line is no longer in the center of the electron emitting element. This line is shifted to the side of the narrowest gate electrode portion. The electrodes then have
Selon la présente invention, il est proposé de réaliser une structure de pixel comportant des largeurs de grille d'extraction de plus en plus étroites au fur et à mesure que l'on s'éloigne du centre du pixel. On peut ainsi créer une structure qui a tendance à focaliser les électrons vers le centre du pixel.According to the present invention, it is proposed to provide a pixel structure with increasingly narrow extraction gate widths as one moves away from the center of the pixel. One can thus create a structure that tends to focus the electrons towards the center of the pixel.
La
Evidemment, la structure d'un pixel comporte généralement un nombre beaucoup plus élevé de bandes d'électrode de grille. Dans ce cas, pour obtenir une focalisation appropriée pour le pixel, on réalise un gradient de largeur de bandes selon l'axe Y (voir la
La
Bien sûr on n'est nullement obligé de réaliser un gradient linéaire et l'on peut réaliser toute forme de profil optimisant la focalisation. En particulier, on a intérêt à focaliser plus sur les bords que près du centre, donc un profil de largeur de grille parabolique par exemple est également très intéressant ou un profil permettant d'optimiser la brillance du pixel. La dernière bande (la plus extérieure) peut être de largeur nulle.Of course there is no obligation to achieve a linear gradient and one can achieve any profile shape optimizing the focus. In in particular, it is advantageous to focus more on the edges than near the center, so a parabolic grid width profile for example is also very interesting or a profile for optimizing the brightness of the pixel. The last (outermost) band may be zero width.
L'intérêt de réaliser des bandes de largeur variable, outre son impact sur la focalisation, permet de garder une structure d'écran facile à réaliser par auto-alignement avec des éléments émetteurs d'électrons centrés dans les gorges.The advantage of making strips of variable width, in addition to its impact on the focusing, makes it possible to keep a screen structure easy to achieve by self-alignment with electron emitting elements centered in the grooves.
On pourra aussi, si l'on souhaite accroître encore l'effet de focalisation décentrer de plus en plus les éléments émetteurs d'électrons dans les fentes au fur et à mesure que l'on s'approche du bord du pixel, le décentrage consistant à rapprocher les rangés d'éléments émetteurs de la bande la plus proche de l'axe AA'. C'est ce qui est représenté sur la
La
Comme le montre la
La
Les
La
Une couche de résine 60 est ensuite déposée sur la structure obtenue. Des ouvertures sont pratiquées dans la résine pour définir les lignes de l'écran et les motifs de grille. Ainsi, une ouverture 61 définit la taille des futurs éléments émetteurs d'électrons. La couche métallique 55 et la couche d'isolant électrique 54 sont gravées par gravure sèche réactive (voir la
Ensuite, les couches 55 et 54 sont gravées par gravure humide en contrôlant le retrait par rapport à l'ouverture 61 de la couche de résine 60. On obtient une ouverture 56 comme le montre la
La
Claims (8)
- Structure emitting electrons by field effect and of the triode type, comprising at least one electronic emission zone resulting from the crossing of a cathode electrode (43) positioned according to a first axis and an extraction gate electrode (45) positioned in a second axis, with an electrical insulating layer separating the cathode electrode from the gate electrode, wherein the electronic emission zone comprises a plurality of electron emitting elements (47) electrically connected to the cathode electrode (43), wherein the electron emitting elements (47) are positioned in rows in openings (46) made in the gate electrode (45) and the electrical insulating layer, where the gate openings (46) are positioned in rows, wherein each gate opening (46) is between two bands (49) of the gate electrode (45), wherein the structure also comprises focussing means for the electronic beams emitted by the electron emitting elements, characterised in that
the focussing means are formed by a dissymmetrical layout of rows of electron emitting elements (47) and their adjacent gate electrode bands (49), wherein the dissymmetry is organised to focus all of the electronic beams and results from a difference in width of gate electrode bands (49) adjacent to a same gate opening (46) so that, for this gate opening, the adjacent band situated the closest to the outside of the electronic emission zone is narrower than the adjacent band situated the closest to the inside of the electronic emission zone - Electron emitting structure according to claim 1, wherein the difference in width of the bands (49) of the gate electrode (45) is such that the width of the bands progressively decreases from the inside towards the outside of the electronic emission zone.
- Electron emitting structure according to claim 2, wherein the gate electrode (45) has, in the central section of the electronic emission zone, at least one gate opening (46) whose adjacent bands (49) are of equal widths, wherein the electrode bands of progressively decreasing width are positioned on either side of this central section.
- Electron emitting structure, according to claim 1, wherein the dissymmetry results from an offset of at least one row of electron emitting elements (47) with respect to the main axis of the gate opening (46) corresponding to this row, wherein the offset consists of bringing said row closer to the centre of the electronic emission zone.
- Electron emitting structure according to claim 4, wherein the dissymmetry results from the offset of several rows of electron emitting elements (47), wherein said offset increases progressively from the inside towards the outside of the electronic emission zone.
- Electron emitting structure according to claim 5, wherein the gate electrode (45) has, in the central section of the electronic emission zone, at least one gate opening (46) whose row of electron emitting elements (47) is centred on its main axis, wherein the rows of electron emitting elements (47) whose offset progressively increases are positioned on either side of this central section.
- Electron emitting structure according to any of claims 1 to 6, wherein the bands of the gate electrode are orientated according to said first axis.
- Electron emitting structure according to any of claims 1 to 6, wherein the bands of the gate electrode are orientated according to said second axis.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR0753086A FR2912254B1 (en) | 2007-02-06 | 2007-02-06 | ELECTRON EMITTING STRUCTURE BY FIELD EFFECT, FOCUSED ON TRANSMISSION |
Publications (2)
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EP1956625A1 EP1956625A1 (en) | 2008-08-13 |
EP1956625B1 true EP1956625B1 (en) | 2009-09-02 |
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Application Number | Title | Priority Date | Filing Date |
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EP08101232A Not-in-force EP1956625B1 (en) | 2007-02-06 | 2008-02-04 | Field-effect electron emission structure with emission focussing |
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US (1) | US7791263B2 (en) |
EP (1) | EP1956625B1 (en) |
JP (1) | JP2008198603A (en) |
DE (1) | DE602008000124D1 (en) |
FR (1) | FR2912254B1 (en) |
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Publication number | Priority date | Publication date | Assignee | Title |
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JPH08315721A (en) * | 1995-05-19 | 1996-11-29 | Nec Kansai Ltd | Field emission cold cathode |
JP3823537B2 (en) * | 1998-06-03 | 2006-09-20 | 双葉電子工業株式会社 | Field emission cathode with focusing electrode |
JP2000243218A (en) * | 1999-02-17 | 2000-09-08 | Nec Corp | Electron emitting device and its drive method therefor |
US7078863B2 (en) * | 2000-09-28 | 2006-07-18 | Sharp Kabushiki Kaisha | Cold-cathode electron source and field-emission display |
JP2003016919A (en) * | 2001-07-03 | 2003-01-17 | Canon Inc | Electron emitting element, electron source, electron source assembly, and image forming device |
JP2003016917A (en) * | 2001-07-03 | 2003-01-17 | Canon Inc | Electron emitting element, electron source and image forming device |
JP4810010B2 (en) * | 2001-07-03 | 2011-11-09 | キヤノン株式会社 | Electron emitter |
JP2003203554A (en) * | 2002-01-08 | 2003-07-18 | Matsushita Electric Ind Co Ltd | Electron emitting element |
FR2836279B1 (en) | 2002-02-19 | 2004-09-24 | Commissariat Energie Atomique | CATHODE STRUCTURE FOR EMISSIVE SCREEN |
WO2004088703A1 (en) * | 2003-03-28 | 2004-10-14 | Sumitomo Electric Industries Ltd. | Cold-cathode electron source, microwave tube using this, and its manufacturing method |
FR2873852B1 (en) * | 2004-07-28 | 2011-06-24 | Commissariat Energie Atomique | HIGH RESOLUTION CATHODE STRUCTURE |
-
2007
- 2007-02-06 FR FR0753086A patent/FR2912254B1/en not_active Expired - Fee Related
-
2008
- 2008-02-01 US US12/024,455 patent/US7791263B2/en not_active Expired - Fee Related
- 2008-02-04 DE DE602008000124T patent/DE602008000124D1/en active Active
- 2008-02-04 EP EP08101232A patent/EP1956625B1/en not_active Not-in-force
- 2008-02-05 JP JP2008025258A patent/JP2008198603A/en not_active Ceased
Also Published As
Publication number | Publication date |
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US7791263B2 (en) | 2010-09-07 |
JP2008198603A (en) | 2008-08-28 |
EP1956625A1 (en) | 2008-08-13 |
DE602008000124D1 (en) | 2009-10-15 |
FR2912254B1 (en) | 2009-10-16 |
FR2912254A1 (en) | 2008-08-08 |
US20080203887A1 (en) | 2008-08-28 |
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