Nothing Special   »   [go: up one dir, main page]

EP0000274B1 - Gasentladungszeige-Speicherpanel - Google Patents

Gasentladungszeige-Speicherpanel Download PDF

Info

Publication number
EP0000274B1
EP0000274B1 EP78300079A EP78300079A EP0000274B1 EP 0000274 B1 EP0000274 B1 EP 0000274B1 EP 78300079 A EP78300079 A EP 78300079A EP 78300079 A EP78300079 A EP 78300079A EP 0000274 B1 EP0000274 B1 EP 0000274B1
Authority
EP
European Patent Office
Prior art keywords
gas discharge
gaseous medium
panel
discharge display
helium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
EP78300079A
Other languages
English (en)
French (fr)
Other versions
EP0000274A1 (de
Inventor
William Edmund Ahearn
Kyu Chang Park
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Business Machines Corp
Original Assignee
International Business Machines Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Publication of EP0000274A1 publication Critical patent/EP0000274A1/de
Application granted granted Critical
Publication of EP0000274B1 publication Critical patent/EP0000274B1/de
Expired legal-status Critical Current

Links

Images

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
    • 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
    • H01J11/50—Filling, e.g. selection of gas mixture

Definitions

  • the present invention relates to AC gas discharge display and memory panels.
  • One of the limitations of the conventional AC gas discharge display panel utilizing the luminous gas mixture is that it produces only one given colour; e.g., reddish-orange colour from neon plus argon mixture and blue colour from argon plus mercury mixture.
  • the prior art does not show how to obtain flexibility of colour presentation with high luminous intensity.
  • French Patent FRA 2195835 on page 3, lines 3 to 14 discloses a gas discharge display panel wherein the ionisable gas medium may be a gas selected from a list which includes oxygen and helium.
  • an AC gas discharge display panel having two substrates and respective dielectric layers on opposing surfaces thereof, a luminous ionizable gaseous medium between said dielectric layers and exhibiting characteristics such that the gaseous medium may periodically be driven by a drive voltage therefore to discharge condition thereacross characterised in that the gaseous medium is helium mixed with oxygen to provide a luminous gaseous medium which exhibits a white light emission.
  • a feature of this invention is a multiple colour gas display panel with enhanced line resolution and memory margin at high frequency drive levels, e.g., >1 1 MHz.
  • Table I shows the wavelengths and bandwidths from a helium-oxygen mixture whose superposition gives an exemplary white panel output.
  • Table II shows typical operating characteristics for an AC plasma panel filled to 400 Torr with a He plus 0.2% O2 mixture.
  • the discharge condition favours the excitation of He metastable states as direct electron excitation or charge transfer to O2 atoms is negligible.
  • the light emission from the gas discharge panel of this invention involves a three-step operation. In the first step there is populating of the main source, He, to metastable states. During the second step, there is transfer of collisional energy (Penning ionization) from the He metastable states to the O2 molecules to form 0 2 ions and excited O2 molecules. Finally, in the third step, the O2 ions recombine with electrons to form 0 2 atoms and emit white light, which is a combination of the various visible spectral lines.
  • AC operations involves a memory or storage effect achieved by charging up the capacitance across a given cell.
  • the capacitance is a result of, the dielectric overcoat on the conductive lines.
  • Alternate sides of the cell charge up with alternate polarity on alternate half cycles of the AC signal.
  • the voltage across the intervening gas of the cell drops to approximately zero.
  • This alternate charging over half cycles of the applied alternating voltages occurs relatively rapidly. That interval provides sufficient time for the electrons to thermalize, i.e., achieve a Gaussian energy distribution and to permit an efficient recombination with the O2 ions.
  • the particular gas mixture employed in accordance with the present invention exhibits the bistable characteristics required for AC operation. Pure helium does not show a bistable hysteresis characteristic. In addition, efficient operation is also based upon the favourable energy match between the He metastables (5eV) and the ionization level (4eV) of the 0 2 molecular.
  • the gas mixture should fall within the following limits: pressure, 300-500 Torr; and oxygen concentration, 0.1-5%.
  • the pressure limit relates to suppressing the helium emission which out of this range has the tendency to form a pinkish halo around the active discharge sites.
  • the oxygen concentration is dependent on the panel surface area. As the equilibrium is established between the gas and surface, some of the oxygen is absorbed on the MgO surface. The amount of oxygen lost to the surface is dependent on the surface area of the MgO topcoat. As an example, for a larger panel this absorbtion of oxygen must be compensated for by filling the panel with more highly doped oxygen mixture. A result of the oxygen being absorbed on the surface is to enhance its stoichiometry which results in a more uniform MgO surface. This is evident by the width of the voltage spread while igniting all cells on or off.
  • Fig. 1 illustrates a typical gas panel display unit 2 which comprises a single panel or plate 3 consisting of a glass substrate 4 having parallel lines of metal 6 either on or imbedded in substrate 4.
  • a dielectric material 8 is deposited by an electron-gun deposition technique to be described hereinafter with particular reference to Fig. 4.
  • Borosilicate glass is an acceptable and preferred material 8.
  • the dielectric material 8 must be electron emissive, which can be accomplished either by incorporating electron emissive material within the borosilicate glass 8 or by depositing an electron emissive layer 21 over layer 8 as shown in Fig. 2.
  • a suitable electron emissive layer is MgO.
  • a second panel 3' which is identical to the first panel comprises a glass substrate 4', into which are imbedded parallel metal lines 6' with an electron-gun deposited layer 8' of borosilicate glass.
  • the parallel metal lines 6 of one panel are established orthogonal to all the metal lines 6' of the other panel.
  • the two panels are secured in position with a rectangular frame 10 placed between the panels of a solid tubular- shaped sealing glass rod. Pressure may be used to enhance the fusing of the two panels together when the sealing glass rod 10 is heated.
  • a shim (not shown) is placed between the glass panels to set minimum separation of the panels as heat is uniformly applied to both panels to achieve a requisite separation between panels.
  • a hole 14 is drilled through one of the two glass panels 3' and a tube 16 is glass soldered to that opening so that after the 2-4 mil spacing between panels 3 and 3' has been evacuated, suitable gas mixture in accordance with the principles of this invention is inserted through the tube at a pressure in the approximate range of 300-500 torr. After the ionizable gas has been inserted into the panel space, the hole 14 is sealed off by tipping off the tube 16.
  • Current-carrying leads 20 are connected to each metal line 6 and 6', so that appropriate actuating signals can be sent through them for exciting or de-exciting the gas discharge panel.
  • Fig. 3 is a perspective view of an AC gas discharge display panel arrangement for the practice of this invention as presented in cross- sectional views in Figs. 1 and 2.
  • the panel comprises an upper glass plate 3 and a lower glass plate 3' separated from and sealed to provide an intervening chamber which is filled with a gas mixture in accordance with the principles of the present invention.
  • Electrically conductive parallel lines 6a-6h are disposed on the lower side of the upper plate 4, and serve as electrodes for supplying a given electrical signal to the intervening sealed chamber between the plates.
  • Electrically conductive parallel lines 6'a-6'j are disposed on the upper side of the lower glass plate 4' and serve as electrodes for supplying a given electrical signal to the other side of the intervening sealed chamber between the plates.
  • the sets of parallel lines are orthogonal to one another and comprise AI-Cu-AI or Al-Cu alloy conductors.
  • the lines on each plate are coated with a dielectric glass which is coated with a refractory layer, such as MgO.
  • a tubulation assembly 19 is provided, which is the tube 16 6 of Fig. 1 shown as sealed off.
  • Fig. 4 It consists of an evacuated chamber 22 in which substrate 4 is established and glass layer 8 and MgO layer 21 are deposited in two sequential evaporations from a single pumpdown. Chamber 22 is evaporated by conventional vacuum pump technology, not shown, via tube 16. Bulk borosilicate glass source 26 is placed in a copper boat 24 within the chamber 22. A tungsten filament 28 within the boat housing is connected to a source 30 of electrical energy for heating said filament 28. Electrons 32 emitted from filament 28 are attracted by a magnet M, shown in dotted line within the boat 24, but not shown in boat 24' for clarity, onto the source material 26 for heating it.
  • a magnet M shown in dotted line within the boat 24, but not shown in boat 24' for clarity
  • An X-Y sweep control unit 31 provides for longitudinal beam positioning and for automatic control of sweeping of the electron beam of both longitudinally and laterally.
  • a large surface area of the source material 26 is uniformly heated and melted.
  • Shutters 38 and 38' are interposable between the source materials 26 and 26' respectively and substrate 4 with metallurgy 6.
  • Shield 36 separates boats 24 and 24' and also helps to prevent cross contamination. Chunks of MgO single crystal source 26' are placed into the boat 24', and deposition of the MgO layer 21 over the glass layer 8 is carried out by opening shutters 38' and 39 during the evaporation of desired amount of MgO.
  • Shutter 38' is in another plane than that of shutter 38 so that the MgO source 26' is bombarded with electrons from electron filament source 28'. Electrical power connections for heating the filament 28' and for deflecting emitted electrons onto MgO source 26' are not shown.
  • Substrate 4 is held at approximately 10 inches away from the evaporation source.
  • a heater 48 maintains it at desired elevated temperatures during the depositions of glass layer 8 and of electron emissive layer 21. The thickness of the deposited layers 8 and 21 are monitored by a detector 42 during the separate depositions.
  • a borosilicate glass source 26 is heated by electron beam bombardment in the evacuated chamber which is maintained at 10- 6 torr so that a molten pool or borosilicate is created having an area in the approximate range of 2 to 10 cm 2 .
  • the power supplied to evaporate the borosilicate glass source material is increased gradually, so that the pre-set area is heated uniformly to a level slightly higher than the eventual power level needed for a desired steady evaporation rate.
  • a large uniformly heated molten pool avoids undesirable fractionation of the borosilicate glass.
  • Shutter 38 is interposed between source 26 and substrate 4 until the source 26 is evaporating at a steady rate.
  • the substrate is maintained at 200°C during evaporation of the borosilicate glass. Then, the shutter 38 is taken out of the path of the evaporating source 26. Accordingly, 3 to 3.5 micron thick layer 8 of transparent and smooth borosilicate glass can be deposited in less than 10 minutes.
  • electroluminescent materials can be placed at selected display cell locations (defined by pairs of electrodes) to be excited by light emission from the gas mixture.
  • the memory, i.e., the image persistance, of electroluminescence material can thus be beneficially utilized.
  • Fig. 5 shows data on how the brightness is controtted over the 3-10 micron dielectric layer thickness range, e.g., layers 8 and 8' of Figs. 1 and 2. Precision of the dielectric thickness must be carefully controlled below about 3 microns because dielectric breakdown of the film must be avoided.
  • the operational parameters of the gas discharge panel used for obtaining the data of Fig. 5 are: .2% 0 2/ He gas mixture; gas pressure of 500 Torr.; and drive frequency of 240 kilohertz.
  • a helium based gas mixture provided for the practice of this invention is its capability to operate at high frequencies e.g., at 3 megahertz and above, without a significant loss of panel margin or increase in sustain voltage levels. This property allows the frequency to be adjusted to achieve a brightness level suitable for the desired display application.
  • Fig. 6 shows data for the linear dependence of brightness on frequency for a .2% O x /He mixture at 500 Torr operating in a typical AC plasma panel structure.
  • Fig. 7 shows the sustain voltage and brightness relationship for a .2% 0 2/ He mixture at 500 Torr under a 240 KHz drive condition as functions of gas pressure.
  • a typical panel structure was employed that had 3 micron thick dielectric layers, 8 and 8', MgO topcoat 21 and a 4 mil chamber spacing between plates 3 and 3'. It is observed that the brightness is relatively constant over the pressure range shown. Actually, this holds up to at least 1000 Torr, the limit of measurement capability available herefor.
  • the voltage difference between the two sustain levels is 20 volts or greater, which number can be referred to as the panel memory margin. It is noted that an optimum margin voltage level occurs in the 400-500 Torr range.
  • an appropriate range of thickness for the secondary electron emission layer e.g., MgO layer 21 of Fig. 1 is approximately in the range of 0.2 to 1.0 microns; and for the glass dielectric layer 8 and 8' of Figs. 1 and 2 is approximately in the range of 3 to 10 microns.
  • He based mixtures in accordance with the principles of this invention for colour capability in gas discharge panel technology allow high line density i.e. great resolution, and high margin panels. Further, such helium based gas mixtures provide suitable condition for thin film phosphor excitation. This results also in high brightness for high line density using narrow lines, e.g., 1 mil or less, for both multicolour and white light capability.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Gas-Filled Discharge Tubes (AREA)

Claims (6)

1. Wechselstrom-betriebener Gasentladungsbildschirm mit zwei Substraten sowie mit auf diesbezüglichen, gegenüberliegenden Oberflächen hiervon liegenden dielektrischen Schichten, mit leuchtendem, ionisierbarem, gasförmigem Medium zwischen beiden dielektrischen Schichten und mit derartigen Markmalen, durch die das gasförmige Medium mittels einer hierfür geeigneten Anregungsspannung periodisch zu Entladungsbedingung hierüber anregbar ist, dadurch gekennzeichnet, daß das gasförmige Medium aus Helium, gemischt mit Sauerstoff besteht, um ein leuchtendes gasförmiges Medium bereitzustellen, das Ausstrahlung weißen Lichts zeigt.
2. Wechselstrom-betriebener Gasentladungsbildschirm, wie in Anspruch 1 beansprucht, weiterhin dadurch gekennzeichnet, daß das gasförmige Medium auf Heliumbasis das Helium in einem ungefähren Druckbereich zwischen 100 und 1000 Torr enthält.
3. Wechselstrom-betriebener Gasentladungsbildschirm, wie in Anspruch 2 beansprucht, weiterhin dadurch gekennzeichnet, daß besagtes Helium zumindest mit 300 Torr vorliegt und mit Sauerstoff bei einem Konzentrationswert von 0,1 bis 5% der gasförmigen Gesamtkonzentration versetzt ist.
4. Wechselstrom-betriebener Gasentladungsbildschirm, wie in Anspruch 3 beansprucht, fernerhin dadurch gekennzeichnet, daß besagter Gasentladungsbildschirm besagte dielektrische Schichten zur Abdeckung von Sätzen elektrischer Leitungszüge auf jeder der einander gegenüberliegenden Substratplatten hiervon enthält, wobei besagte dielektrische Schichten jeweils eine hierauf niedergeschlagene, widerstandsfähige, stark emissionsfähige Schicht aufweisen, deren Oberfläche auf einer Seite hiervon mit dem gasförmigen Medium auf Heliumbasis in Berührung steht und deren Dicke jeweils derart ist, daß die Leuchtstärke des angeregten gasförmigen Mediums zu optimieren ist.
5. Wechselstrom-betriebener Gasentladungsbildschirm, wie in Anspruch 4 beansprucht, fernerhin dadurch gekennzeichnet, daß besagte widerstandsfähige, stark Sekundärelektronenemissions-fähige Schicht eine MgO-Schicht darstellt, die aus besagtem Sauerstoff in besagtem gasförmigen Medium resultierende Stöchiometrie stiegert.
6. Wechselstrom-betriebener Gasentladungsbildschirm, wie in Anspruch 5 beänsprucht, dadurch gekennzeichnet, daß ein hinzugefügtes Filter vorgesehen wird, um aus der Abstrahlung weißen Lichtes eine vorgegebene Farbe auszuwählen.
EP78300079A 1977-06-30 1978-06-26 Gasentladungszeige-Speicherpanel Expired EP0000274B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US05/811,749 US4147958A (en) 1977-06-30 1977-06-30 Multicolor gas discharge display memory panel
US811749 1977-06-30

Publications (2)

Publication Number Publication Date
EP0000274A1 EP0000274A1 (de) 1979-01-10
EP0000274B1 true EP0000274B1 (de) 1982-06-23

Family

ID=25207460

Family Applications (1)

Application Number Title Priority Date Filing Date
EP78300079A Expired EP0000274B1 (de) 1977-06-30 1978-06-26 Gasentladungszeige-Speicherpanel

Country Status (6)

Country Link
US (1) US4147958A (de)
EP (1) EP0000274B1 (de)
JP (1) JPS5413256A (de)
CA (1) CA1100563A (de)
DE (1) DE2861907D1 (de)
IT (1) IT1120101B (de)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3016808A1 (de) * 1980-05-02 1981-11-12 Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt Gasentladungsanzeigebildschirm
US4456400A (en) * 1980-10-21 1984-06-26 Heide Guenter Process of safely disposing of waste materials
US4429303A (en) 1980-12-22 1984-01-31 International Business Machines Corporation Color plasma display device
GB2109628B (en) * 1981-11-16 1985-04-17 United Technologies Corp Optical display with excimer flurorescence
JPS60139381A (ja) * 1983-12-27 1985-07-24 Tohoku Electric Power Co Inc 石炭灰を主体とするしや水材料
DE69511813T2 (de) * 1994-05-11 2000-03-16 Koninkl Philips Electronics Nv Dünnpaneelanzeigevorrichtung
JPH11125809A (ja) * 1997-10-23 1999-05-11 Sharp Corp プラズマアドレス情報表示素子
KR19990062412A (ko) * 1997-12-05 1999-07-26 손욱 헬륨 방전 디스플레이
KR100911005B1 (ko) * 2004-05-31 2009-08-05 삼성에스디아이 주식회사 외부 압력에 따라 휘도가 조정되는 방전 디스플레이 장치
US8048476B2 (en) * 2005-11-10 2011-11-01 Panasonic Corporation Method of manufacturing plasma display panel
US10892918B1 (en) 2019-07-26 2021-01-12 Xilinx, Inc. System and method for decision feedback equalizers

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3761773A (en) * 1968-01-19 1973-09-25 Owens Illinois Inc Interfacing circuitry system for multiple gaseous display/memory unit
US3704386A (en) * 1971-03-19 1972-11-28 Burroughs Corp Display panel and method of operating said panel to produce different colors of light output
JPS5140697B2 (de) * 1972-06-30 1976-11-05
US3886393A (en) * 1972-08-11 1975-05-27 Owens Illinois Inc Gas mixture for gas discharge device
US3925697A (en) * 1972-10-24 1975-12-09 Owens Illinois Inc Helium-xenon gas mixture for gas discharge device
US4053804A (en) * 1975-11-28 1977-10-11 International Business Machines Corporation Dielectric for gas discharge panel

Also Published As

Publication number Publication date
IT7824901A0 (it) 1978-06-23
JPS5413256A (en) 1979-01-31
DE2861907D1 (en) 1982-08-12
IT1120101B (it) 1986-03-19
US4147958A (en) 1979-04-03
EP0000274A1 (de) 1979-01-10
CA1100563A (en) 1981-05-05

Similar Documents

Publication Publication Date Title
EP0732719B1 (de) Entladungsvorrichtung mit einer Kathode mit einem Array von Mikro-Höhlungen
US3838307A (en) Color plasma display
EP0054618B1 (de) Mehrfarbige Wechselspannungs-Plasmadisplaytafel
EP0783763B1 (de) Elektronenemittierende elektrode und verfahren zu deren herstellung
KR100503466B1 (ko) 방전램프용냉음극,상기냉음극이장치된방전램프,및상기방전램프의동작방법
US6935913B2 (en) Method for on-line testing of a light emitting panel
EP0000274B1 (de) Gasentladungszeige-Speicherpanel
US4843281A (en) Gas plasma panel
US3836810A (en) Picture display device comprising a plurality of light producing elements
EP1808881B1 (de) Schutzfilm für eine plasmaanzeigetafel, herstellungsverfahren für den schutzfilm, plasmaanzeigetafel und herstellungsverfahren dafür
US5057740A (en) Photoemissive trigger for backlighted thyratron switches
US6005343A (en) High intensity lamp
Park et al. Effects of MgO thin film thickness and deposition rate on the lifetime of ac plasma display panel
JP2001332175A (ja) 交流型プラズマディスプレイパネルおよびその製造方法
US6509701B1 (en) Method and device for generating optical radiation
JP2000311660A (ja) ガス放電ランプ
CA1086374A (en) Gas panel assembly
US3899636A (en) High brightness gas discharge display device
JP2793532B2 (ja) プラズマディスプレイパネルの製造方法
US4041345A (en) Blue color AC gas discharge display panel and method
US6000982A (en) Method of manufacturing a cold-cathode for a discharge device
US4866339A (en) Beam mode fluorescent lamp
JPH04160732A (ja) プラズマディスプレイパネルおよびその製造方法
RU2210140C2 (ru) Способ и устройство для получения оптического излучения
JP2005353455A (ja) プラズマディスプレイパネル

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB

17P Request for examination filed
GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): DE FR GB

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY

Effective date: 19820623

REF Corresponds to:

Ref document number: 2861907

Country of ref document: DE

Date of ref document: 19820812

EN Fr: translation not filed
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Effective date: 19830301

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19881117

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT