Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J11/00—Gas-filled discharge tubes with alternating current induction of the discharge, e.g. alternating current plasma display panels [AC-PDP]; Gas-filled discharge tubes without any main electrode inside the vessel; Gas-filled discharge tubes with at least one main electrode outside the vessel
  • H01J11/10—AC-PDPs with at least one main electrode being out of contact with the plasma
  • H01J11/12—AC-PDPs with at least one main electrode being out of contact with the plasma with main electrodes provided on both sides of the discharge space
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
  • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
  • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
  • G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
  • G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
  • G09G3/291—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels controlling the gas discharge to control a cell condition, e.g. by means of specific pulse shapes
• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G3/00—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes
  • G09G3/20—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters
  • G09G3/22—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources
  • G09G3/28—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels
  • G09G3/288—Control arrangements or circuits, of interest only in connection with visual indicators other than cathode-ray tubes for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix no fixed position being assigned to or needed to be assigned to the individual characters or partial characters using controlled light sources using luminous gas-discharge panels, e.g. plasma panels using AC panels
  • G09G3/296—Driving circuits for producing the waveforms applied to the driving electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J11/00—Gas-filled discharge tubes with alternating current induction of the discharge, e.g. alternating current plasma display panels [AC-PDP]; Gas-filled discharge tubes without any main electrode inside the vessel; Gas-filled discharge tubes with at least one main electrode outside the vessel
  • H01J11/20—Constructional details
  • H01J11/22—Electrodes, e.g. special shape, material or configuration
  • H01J11/24—Sustain electrodes or scan electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J11/00—Gas-filled discharge tubes with alternating current induction of the discharge, e.g. alternating current plasma display panels [AC-PDP]; Gas-filled discharge tubes without any main electrode inside the vessel; Gas-filled discharge tubes with at least one main electrode outside the vessel
  • H01J11/20—Constructional details
  • H01J11/34—Vessels, containers or parts thereof, e.g. substrates
  • H01J11/38—Dielectric or insulating layers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
  • H01J2211/00—Plasma display panels with alternate current induction of the discharge, e.g. AC-PDPs
  • H01J2211/20—Constructional details
  • H01J2211/22—Electrodes
  • H01J2211/24—Sustain electrodes or scan electrodes
  • H01J2211/245—Shape, e.g. cross section or pattern

Definitions

• the invention relates to the delimitation of zones of ignition, of expansion and of stabilization of discharges in the various cells or zones of discharges of a plasma display panel.
• a plasma panel is generally provided with at least a first and a second network of coplanar electrodes whose general directions are parallel, where each electrode Y of the first network is adjacent to an electrode Y 'of the second network, is paired with it , is intended to serve a set of discharge zones, and includes, for each discharge zone served:
• a conductive zone Z a called discharge ignition which comprises an ignition edge facing said electrode of the second network
• slabs are used to manufacture conventional plasma panels of the type comprising a slab 11 of coplanar discharges of the aforementioned type and another slab 12 provided with a network of addressing electrodes, providing between them a two-dimensional assembly bringing together said zones. landfills filled with landfill gas.
• Each discharge zone is positioned at the intersection of an addressing electrode X and a pair of electrodes of the coplanar discharge plate Y, Y '; each set of discharge zones served by the same pair of electrodes generally corresponds to a horizontal line of dump or sub-pixel areas of the panel; each set of discharge zones served by the same addressing electrode generally corresponds to a vertical column of discharge zones or sub-pixels.
• the adjacent discharge zones are generally delimited by horizontal barriers 15 and / or vertical 16; these barriers generally also serve as spacers between the slabs.
• the cell shown in Figures 1A and 1B is rectangular in shape; other cell geometries are disclosed by the prior art; the largest dimension of this cell extends parallel to the addressing electrodes X; let Ox be the longitudinal axis of symmetry of this cell; at each discharge zone served by a pair of electrodes which forms a discharge cell, the portions or elements of electrodes Y, Y 'delimited by the barriers 15, 16 have here a constant width measured in the direction perpendicular to the Ox axis.
• FIG. 15 of the document EP0782167 - PIONEER and FIG. 3A below show a coplanar discharge slab of the aforementioned type where, at each discharge zone served by a pair of electrodes, each electrode of this pair comprises an element T-shaped comprising a crossbar 31 facing the other electrode and a central leg of constant width 32; each electrode element is electrically connected by a conductive bus 33 by the foot of its central leg.
• T shape is shown in Figure 14 of the same document EP0782167 -PIONEER: it is the inverted U shape which has two side legs (instead of a central one) perpendicular to the same crossbar d 'ignition as before, which are each connected to one end of this bar; after ignition, the discharge is subdivided and then extends along two parallel lateral expansion paths, each corresponding to a leg of the inverted U, the two paths meeting at the level of the conductive bus of the electrode.
• each lateral leg of U 42a, 42b is shared between two adjacent cells and the transverse bars of the elements of the same electrode form a continuous conductor, so that each coplanar electrode has the form of a ladder, the first upright of which serves as an ignition zone Z a , the bars are positioned at the edge of the discharge zone and serve as zones for expanding the discharges Z b , and a second upright serving as the stabilization zone Z c .
• Such a process of spreading the discharges along an expansion zone forming an electrode portion is favorable to the production yield of ultraviolet radiation from the discharges and to a wider distribution of the surfaces of excited phosphors.
• the subject of the invention is a coplanar discharge slab for delimiting discharge zones in a plasma display panel, which comprises:
• the electrode element acts as a cathode
• the surface of the dielectric layer which covers it is positively charged.
• the two opposite electrode elements and the underlying dielectric layer are identical and symmetrical with respect to the center of the inter-electrode space.
• each coplanar maintenance discharge in this panel then successively comprises an ignition phase, an expansion phase, and an end of discharge or stabilization phase during which the cathode sheath of the discharge respectively does not not move, move, disappear or stabilize.
• the stable operating point of the discharge cannot be the ignition zone once the discharge has started, and, once initiated, the discharge necessarily spreads in the expansion zone along the surface of the dielectric layer towards the end of discharge edge.
• the invention also relates to a coplanar discharge panel for delimiting discharge zones in a plasma display panel, which comprises:
• a maximum energy dissipation of the discharges is then advantageously obtained in the end of discharge zone Z c with high light output.
• the width W e (x) of said electrode element is constant in said range of values of x.
• said electrode element is subdivided into two lateral conductive elements which are symmetrical with respect to the axis Ox and which are disjoint at least in an area where x is included in an interval [x ab , x b3 ],
• p (x) increases continuously or discontinuously as a function of x in said interval [x ab , x c ], and in that, if we consider the mean line of each lateral conductive element drawn, for a position x given, halfway between the lateral edges of this lateral element, in the zone where x a ⁇ x ⁇ x bc , the tangent in x to the mean line of this element makes with the axis Ox an angle between 20 ° and 40 °, and in that d e . p (x ab ) ⁇ 350 ⁇ m.
• the electrostatic influence of one lateral conducting element on the other is strong enough here to allow, in accordance with the invention, a variation of the standard potential at the surface of the dielectric between V n . preferably higher than 0.9 and V n. bc preferably close to 1, while keeping the width of each lateral conductive element constant.
• the addressing panel comprising: a network of addressing electrodes coated with a dielectric layer which are oriented and positioned so as to each cross a pair of electrodes of the coplanar slab at one of said discharge zones,
• ignition crossbar whose width is greater than or equal to W c , the length of which measured along the axis Ox is L a , one edge of which corresponds to said ignition edge,
• a crossbar known as a discharge stabilization whose width is greater than or equal to W c , whose length measured along the axis Ox is L s , one edge of which corresponds to said end of discharge edge,
• the reduction of the gap separating the two electrode elements at the level of the lateral zones Z a . pl , Z a . p2 near the barriers increases the electric field in this area and compensates for the reduction of primary particles resulting from the wall effect by locally adapting the Pashen conditions. There is thus obtained a reduction in the ignition potential, with a constant ignition zone surface, or a reduction in the ignition zone surface with a constant ignition potential.
• one or the other of the plasma panels according to the invention comprises supply means suitable for generating between the coplanar electrodes of the different pairs of series of so-called maintenance voltage pulses with constant stages.
• the invention advantageously makes it possible to appreciably increase the light output and the lifetime of the plasma panels by using this conventional and economical type of maintenance generator.
• FIG. 2A represents the state of a discharge at time T1 and at time T2 in a cell of the type of FIG. 1A and 1 B
• FIG. 2B represents the evolution of the discharge current as a function of time T;
• FIG. 10A to 10D, 11A to 11 D illustrate variants of a second general embodiment of the invention based on a structure where the electrode element has a variable width
• FIG. 20B shows a cell structure of the prior art with three transverse bars which illustrates a third general embodiment of the invention
• each plasma discharge which arises between the electrodes of a pair, one serving as a cathode and the other as anode, comprises an ignition phase and a expansion phase;
• FIG. 2A shows a schematic longitudinal section of a cell of the type with coplanar discharge zone as described in FIG. 1A
• FIG. 2B represents the evolution of the electric current between the coplanar electrodes of this cell during a maintenance discharge.
• this transverse field causes the displacement of the cathodic sheath more and more far from the ignition zone as the ionic charges accumulate on the dielectric surface which covers the cathode; it is this displacement which leads to the expansion of the plasma discharge; the cathode sheath is positioned at the level where the plasma ions are deposited, at the limit of the expansion zone; during discharges, the displacement of the cathode sheath follows the path of the electrode elements in each cell.
• the expansion zone Z b therefore corresponds to the zone swept by the displacement of the cathode cladding of the discharge.
• FIG. 6 schematically represents a discharge zone 3 of rectangular shape delimited between its largest faces by a coplanar slab 1 carrying a pair of symmetrical electrode elements 4, 4 ′ arranged on either side of an inter interval -electrode or gap 5 and by an addressing plate 2 carrying, but not necessarily, an addressing electrode X of general direction perpendicular to the electrode elements 4, 4 ′ and coated with a dielectric layer 7; the ends of the electrode elements opposite the gap are electrically connected to a conductive bus Y c not shown, which serves to supply them with voltage; the coplanar electrodes 4, 4 ′ are coated with a dielectric layer 6.
• the specific longitudinal capacity of the dielectric layer in the stabilization zone Z c is greater than the specific longitudinal capacity of the dielectric layer at any other point in the expansion zone Z b and in the ignition zone Z a ; a maximum of energy dissipation is thus obtained in the high efficiency end-discharge zone Z c .
• the software therefore presents a grid of 48 steps x 48 steps on which one enters, according to a cross section of the cell to study the influence of the electrode width, at all points the shape of the dielectric layer covering the electrodes and its local dielectric constant. Then bars of variable width are positioned on this grid representing on the one hand the coplanar electrode element on the front coplanar panel, on the other hand the addressing electrode on the other rear panel. For the modeling tests, a coplanar electrode of variable width was chosen centered on the axis Ox.
• E1 (x) the thickness expressed in microns and P1 (x) the relative permittivity of the dielectric layer above each electrode element 4, 4 ′ at position x along the Ox axis of expansion of the dump ;
• E2 (x) the thickness expressed in microns and P2 (x) the relative permittivity of the dielectric layer above the addressing electrode X or of the slab 2 in the absence of an addressing electrode, at the position x along the Ox axis of expansion of the discharge.
• each electrode element has, for Xt ⁇ x ⁇ cd , a thickness greater than 5 times the thickness of the electrode element in the rest of the discharge zone; this over-thickness zone generally corresponds to the supply bus of the electrode elements;
• FIG. 9 graphically presents the general law connecting the width of the electrode element W e . ua (logarithmic scale in arbitrary unit “ua”) and the standard potential V norm which is obtained on the surface of the dielectric layer covering this electrode element before a discharge, where V norm has been previously defined.
• FIGS. 10A, 10B, 10C, 10D represent examples of shapes of electrode elements in accordance with this second general embodiment of the invention, according to a top view (Oz axis of FIG. 6) of a half - plasma display screen cell:
• the cell walls play an important role in the behavior and the efficiency of production of ultraviolet radiation from the discharge, in particular at the regions of the electrode element which are located in the vicinity of these walls, in the zones where this element has a width W e close to the width W c of the cell.
• this zone of influence of the walls typically extends up to a distance from the walls of between 30 and 50 ⁇ m, depending, in particular, on the composition and the pressure. landfill gas.
• the electrode elements are connected, behind the ignition and expansion zones, to the bus Y b of the coplanar electrodes Y, Y '.
• the bus is integrated into the stabilization zone, in which case one encounters the disadvantages of the aforementioned wall effect resulting from too wide a width of the stabilization zone; this case is illustrated in FIG. 2C described below;
• FIGS. 11A to 11 D illustrate other examples of the second general embodiment of the invention.
• FIG. 12 shows the evolution of the normalized ignition voltage V a (solid line curve) as a function of the width W a of the ignition front.
• width W a of the ignition zone there is a minimum width W a _ min above which the ignition voltage V a is not or only slightly modified by the width W a of the ignition front. This value of W a . min corresponds to the critical width beyond which the walls cause significant losses on primary particles created in the space between W a . min and W c .
• FIG. 16 represents an electrode element according to this preferred embodiment of the invention, where the two lateral conductive elements give rise to two expansion zones Z. pl and Z b . p2 arranged symmetrically with respect to the longitudinal axis Ox of symmetry of the cell.
• the ignition properties of the discharge are significantly improved.
• the electrostatic influence of one lateral conductive element on the other increases and disturbs the evolution of the surface potential on the dielectric layer above each lateral conductive element, to the point that one departs from the general objective of increasing potential pursued by the invention even if the total width W e of the conductive elements satisfies, in the expansion zone Z b , the general law defined above with reference to the second general embodiment of the invention.
• the best compromise consists in using, according to a variant of the invention, electrode elements subdivided, in the ignition zone and most of the expansion zone, into two axially-symmetrical lateral conductive elements, where :
• pl and Z b . p2 therefore functions as a discharge initiator which does not cause any additional energy dissipation for the expansion; for this purpose, it is preferable that the elongation ⁇ L a is chosen so that ⁇ L a + L a ⁇ 80 ⁇ m, and that the width W ⁇ of the lug 201, measured along the axis Oy, is such that W e . ab ⁇ W a . j ⁇ 80 ⁇ m.
• FIG. 21 describes the distribution of the surface potential of the dielectric layer according to sections A - curve A - and B - curve B - of the cell in FIG. 20A. This distribution is obtained using the SIPDP-2D software previously mentioned.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Power Engineering (AREA)
• Computer Hardware Design (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Gas-Filled Discharge Tubes (AREA)

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• 2002
  • 2002-06-24 FR FR0208094A patent/FR2841378A1/fr active Pending
• 2003
  • 2003-06-19 JP JP2004514877A patent/JP4637576B2/ja not_active Expired - Fee Related
  • 2003-06-19 EP EP03760707A patent/EP1516348B1/de not_active Expired - Lifetime
  • 2003-06-19 AU AU2003255512A patent/AU2003255512A1/en not_active Abandoned
  • 2003-06-19 US US10/518,567 patent/US7586465B2/en not_active Expired - Fee Related
  • 2003-06-19 KR KR1020047020969A patent/KR100985491B1/ko not_active Expired - Fee Related
  • 2003-06-19 WO PCT/EP2003/050243 patent/WO2004001786A2/fr not_active Ceased
  • 2003-06-19 CN CNB038149087A patent/CN100377281C/zh not_active Expired - Fee Related

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