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
  • H01J11/20—Constructional details
  • H01J11/34—Vessels, containers or parts thereof, e.g. substrates
  • H01J11/42—Fluorescent layers
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
  • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
  • C09K11/59—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing silicon
  • C09K11/592—Chalcogenides
  • C09K11/595—Chalcogenides with zinc or cadmium
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
  • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
  • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
  • C09K11/7766—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
  • C09K11/7777—Phosphates
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K11/00—Luminescent materials, e.g. electroluminescent or chemiluminescent
  • C09K11/08—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials
  • C09K11/77—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals
  • C09K11/7766—Luminescent materials, e.g. electroluminescent or chemiluminescent containing inorganic luminescent materials containing rare earth metals containing two or more rare earth metals
  • C09K11/778—Borates
• • 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
• • 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

Definitions

• the invention relates to a color display device comprising a first substrate provided with a layer of fluorescent material, and a second, transparent substrate, said color display device comprising means for addressing pixels during use.
• the display device may be a plasma display device but also, for example, a display device of the field emission type.
• the address electrodes may be present on both the first and the second substrate in the case of a plasma display device.
• the fluorescent material is patterned or not patterned.
• a display device of this type is used, inter a a, in large-area, flat display screens, for example, for HDTV.
• a color display device (plasma display panel or PDP) of the type mentioned above is described in EP-A-0 488 891.
• This application describes measures for obtaining grey values or color gradations.
• the frame time is divided into a plurality of sub-frames having a weighted duration (for example in the ratio 1:2:4:. choir:128).
• a frequently used phosphor such as Zn 2 SiO 4 :Mn (willemite) exhibits saturation phenomena.
• the efficiency of the phosphor (number of emitted photons/number of incoming photons) deteriorates, so that the brightness decreases.
• an object of the present invention to provide a display device of the type described, which has an optimum brightness or luminance, also when a given color is fully driven.
• a color display device is characterized m that the layer of fluorescent mate ⁇ al comp ⁇ ses at least two different phosphors of substantially the same color at the location of a pixel.
• Substantially the same color is herein understood to mean that the difference in spectral color of the emission peaks of the phosphors, measured as the distance in C.I.E coordinates ( ⁇ , y co-ordinates) is at most 0.35 (and preferably at most 0.25)
• the invention is based on the recognition that the decrease of the efficiency for different phosphors depends in different manners on the number of incoming photons. By using two phosphors with a difference in a variation of the efficiency, it will be possible to mix colors of phosphors which, as regards color are (slightly) different but exhibit a different behavior as regards loss of efficiency in the case of full drive (maximum brightness), or to choose between the two phosphors.
• a non-saturating phosphor is herein understood to mean a phosphor in which the number of emitted photons per unit of surface and time has decreased at most 15% in the case of a drive yielding a brightness (or luminance) of 500 Cd/m 2 as compared with a drive yielding a brightness of 10 Cd m 2 .
• Suitable non-saturating phosphors are, for example:
• a preferred embodiment of a display device is characterized in that the layer of fluorescent material at the location of a pixel, viewed in a direction transverse to the first substrate, comprises at least two sub-pixels having different phosphors of substantially the same color for different sub-pixels.
• An incoming (video) signal can now be split up, for example, into two or more sub-signals each supplying one of the sub- pixels with a separate drive signal. By means of the sub-signals, the extent of mixing of the colors is then adjusted, or a choice is made between the sub-pixels.
• Fig. 1 is a diagrammatic cross-section of a part of a plasma display device
• Fig. 2 shows diagrammatically a part of a plasma display device
• Fig. 3 shows diagrammatically a distribution of phosphors across a pixel
• Fig. 4 shows the associated C.I.E. color triangle
• Figs. 5 to 8 show variations of Fig. 3.
• Fig. 1 shows a plasma display device 10, in this case an AC display panel (AC PDP or AC Plasma Display Panel), having a first substrate 1 provided with two display electrodes 2 which are coated with a dielectric layer 3 (for example, glass), and a second, transparent substrate 5 provided with fluorescent material 8.
• the second substrate 5 is provided with address electrodes 6.
• a sub-pixel as defined by the address electrode 6 and the display electrodes 2 is bounded by partition walls 7 which bound a discharge space.
• the partition walls 7 are not absolutely necessary, while display electrodes and address electrodes may be alternatively present on one substrate.
• a gas discharge mixture 9 consisting, in this embodiment, of a helium-xenon mixture, is present in the discharge space between the substrates 1, 5.
• UV radiation is generated in plasma display devices (plasma display panels or PDPs) in the discharge space at the area of a (sub-)pixel, which UV radiation causes the fluorescent material 8 (phosphors) to luminesce.
• the display electrodes 2 are driven, for example, from X and Y drivers 20, 21 and the address electrodes are driven from an A driver 22 (Fig. 2).
• an incoming signal 11 is stored in a frame memory 12 and in a sub-frame generator 13.
• the required pulses are generated in the processing unit 14 for the reset pulses, the ignition pulses and the sustain pulses which energize the display electrodes 2 via the X and Y drivers 20, 21, while addressing takes place via the A driver 22 controlled by an address generator 16.
• Mutual synchronization takes place via a timing control circuit 15.
• the ignition is maintained by the sustain pulses across the display electrodes within a pixel.
• Dependent on the grey tint to be displayed, these are offered more frequently or less frequently per pixel.
• the sustain frequency therefore determines, together with the grey tint, the number of times a UN photon impinges upon a phosphor.
• Fig. 3 is a diagrammatic front-elevational view of a display device, particularly the location of a number of phosphors 8, 8', 8", 8'" with the colors red (R), green (GO, blue (B) and a second color green (G 2 ).
• the broken line 25 diagrammatically represents a pixel.
• the C.I.E. color triangle of Fig. 4 shows the luminances associated with these phosphors as B(Y0, R(Y 2 ), G](Y 3 ) and G 2 (Y 4 ) (Y: luminance) in this color triangle.
• the point Yo can be realized by weighted excitation of the phosphors B, R and Gi or by weighted excitation of the phosphors B, R and G 2 .
• Y 3 (GO and Y 4 (G 2 ) is made in the device of Fig. 2 by processing information about the color to be displayed, stored in the frame memory 12, in the processing unit 14.
• this unit comprises, for example, a microprocessor or a lookup table in which the behavior (notably the efficiency of the phosphors as a function of the frequency (grey scale to be displayed) is stored.
• the X and Y drivers are supplied with drive signals for the relevant sub-pixels.
• Figs. 5 to 7 show a number of variants in which the phosphors are distributed across sub-pixels in different ways.
• a pixel 25 comprises three sub-pixels, the green sub-pixel comprising a phosphor layer G m which consists of a mixture of willemite and CBT.
• the invention is of course not limited to the embodiments described hereinbefore.
• the sub-pixels may have, for example, different surface areas, which may be incorporated in the data in the processing unit 14.
• the invention is also applicable to field emission display devices in which the efficiency of given phosphors is also dependent on the luminance to be adjusted.
• the invention relates to a luminescence-based color display device having at least one extra phosphor per pixel, in which, dependent on the color to be displayed and the luminance (brightness), the combination of sub-pixels to be driven is determined.
• the invention relates to each and every novel characteristic feature and each and every combination of characteristic features.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Inorganic Chemistry (AREA)
• Materials Engineering (AREA)
• Organic Chemistry (AREA)
• Plasma & Fusion (AREA)
• Computer Hardware Design (AREA)
• Power Engineering (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Gas-Filled Discharge Tubes (AREA)
• Control Of Indicators Other Than Cathode Ray Tubes (AREA)
• Cathode-Ray Tubes And Fluorescent Screens For Display (AREA)
• Transforming Electric Information Into Light Information (AREA)
• Video Image Reproduction Devices For Color Tv Systems (AREA)
• Luminescent Compositions (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

Cited By (7)

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Citations (4)

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• 1999
  • 1999-12-16 TW TW088122111A patent/TW434628B/zh not_active IP Right Cessation
• 2000
  • 2000-01-10 EP EP20000904908 patent/EP1074036B1/en not_active Expired - Lifetime
  • 2000-01-10 JP JP2000601669A patent/JP4776078B2/ja not_active Expired - Lifetime
  • 2000-01-10 DE DE60015244T patent/DE60015244T2/de not_active Expired - Lifetime
  • 2000-01-10 KR KR1020007011742A patent/KR20010071169A/ko not_active Ceased
  • 2000-01-10 WO PCT/EP2000/000213 patent/WO2000051156A1/en not_active Ceased
  • 2000-01-10 KR KR1020077004712A patent/KR100898190B1/ko not_active Expired - Lifetime
  • 2000-02-22 US US09/510,143 patent/US6388644B1/en not_active Expired - Lifetime
• 2008
  • 2008-02-21 KR KR1020087004174A patent/KR100919959B1/ko not_active Expired - Fee Related

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