CA1250038A - Electroluminescent display device - Google Patents
Electroluminescent display deviceInfo
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- CA1250038A CA1250038A CA000445263A CA445263A CA1250038A CA 1250038 A CA1250038 A CA 1250038A CA 000445263 A CA000445263 A CA 000445263A CA 445263 A CA445263 A CA 445263A CA 1250038 A CA1250038 A CA 1250038A
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Abstract
ABSTRACT OF THE DISCLOSURE
Electroluminescent display device suitable for ac and unipolar pulse voltage operation, and ensuring an increased lumi-nescent brightness and a low driving voltage, comprises a trans-parent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed, wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes at least one semiconduc-tive electrode which contacts said electroluminescent layer and is comprised of a semiconductive material containing at least one chemical compound selected from the group consisting of the chem-ical compounds of Groups II-VI, and wherein said second energiz-ing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
Electroluminescent display device suitable for ac and unipolar pulse voltage operation, and ensuring an increased lumi-nescent brightness and a low driving voltage, comprises a trans-parent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed, wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes at least one semiconduc-tive electrode which contacts said electroluminescent layer and is comprised of a semiconductive material containing at least one chemical compound selected from the group consisting of the chem-ical compounds of Groups II-VI, and wherein said second energiz-ing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
Description
~5~3~
The present Inventlon relates to eiectroluminescent dlsplay devlces and more partlcularly to an elec-trolumlnescent dlsplay devlce havlng a novel constructlon whlch ensures an Improved lumlnescent brlghtness and low voltage drlvlng.
In the past, electrolumlnlescent dlsplay devlces (herelnafter slmply referred to as IEL dlsplay devlces) have been known Includlng EL dlsplay devlces ~Df a double lnsulatlng layer type In whlch the sldes of an electrolumlnescent llght emlttlng layer (herelnafter slmply referred to as an EL layer) are held between Insulatlng layers whlch are In turn held externally between a transparent eiectrode made essentlally of lndlum oxlde (In~03) or tln oxlde (SnO2) and a metal electrode made of alu-mlnum (Al) or the llke and EL dlsplay devlces of a slngle Insu-latlng layer type In whlch an EL layer ls dlrectly formed on atransparent electrode made essentlally of lndlum oxlde or tln oxlde and then an lnsulatlng layer and a metal electrode are suc-cesslvely provlded on the EL layer. If these two types of EL
dlsplay devlces are constructed so that they have the same total lnsulatlng layer thlckness and the same EL emltting thlckness and an ac voltage or pulse voltage ls applled to cause llght emls-slon, the EL dlsplay devlce of the slngle Insulatlng layer type ls lower than the EL dlsplay devlce of the double lnsulatlng layer type ln terms of lumlnescent threshold voltage and also the EL dlsplay devlce of the ciouble lnsulatlng layer type ls hlgher than the EL dlsplay devlce of the slngle lnsulatlng layer type In terms of iumlnescent brlghtness. Thus, the known EL display devlces have had thelr own merlts and demerlts and therefore . there has been a demand for an EL dlsplay devlce whlch has a lower luminescent threshold voltage or ls adapted to be drlven at a lower voltage and whlch also has a hlgher lumlnescent brlghtness.
The present Inventlon provides an EL dlsplay devlce of 3~ the type In whlch energl~lng means apply slgnal voltages corre-spondlng to lnformatlon to an assembly of an EL layer Includlng zlnc sul~ide contalnlng a lumlnescently actlve materla~ and an Insulatlng layer thereby dlsp~aylng the Informatlon In the form of an Image, whereln one of the energlzlng means arranged on the slde of the EL layer Includes a plurallty of semlconductlve elec-trodes contalnlng at least one compound selected from the group conslsts of the chemlcal compounds of Groups ~T ~Z~ or at least one compound selected from the group of chemlcal compounds of Groups 11-~1 and tln oxlde thus ensur5ng a reduced lumlnescent threshold voltage and an Increased lumlnescent brlghtness.
As regards ~roup Il-gl chemlcal compound constltutlng the semlconductor electrodes whlch form one of the energlzlng means, at least one of zlnc oxlde (ZnO), zlnc selenlde (ZnSe), ~Inc tellurIde (ZnTe), zlnc sulfIde (7nS), cadmlum sulfIde (CdS) and cadmlum selenlde (CdSe) Is preferred and partlcularly zlnc oxlde Is preferred most. Also, It Is needless to say that the semlconductor electrodes may be made of at least one of these chemlcal compounds and tln oxlde.
Any one of the heretofore known materials may be used as the lumlnescently actlve materlal added to the zlnc sulflde of the EL layer and It Is only necessary to make the selectlon In accordance wlth the deslred lumlnescent color. Manganese (Mn), copper (Cu), sllver (Ag), alumlnum (Al), terblum (Tb), dysproslum (Dy~, erbium (Er), praseodymlum ~Pr), samarlum (Sm), holmlum (Ho), thullum (Tm) and thelr halIdes may be clted as examples o~
the lumlnescenln~ly actlve materlal.
~he present Inventlon wlll be apparent from the follow-Ing detalled descrlptlon taken In conJunctlon wlth the accompany-lng drawlngs, ~n whlch:-Flg. 1 Is a partly cutaway perspectlve vlew showlng an example o~ an EL dlsplay devlce accordlng to the Inventlon;
~'~S~3~3 F Ig . 2 Is a graph showlng applled voltage-lumlnescent brlghtness character~stlc curves for the EL dlsplay devlce shown In F Ig . 1 I n comparlson wlth the applled voltage-lumlnescent brlghtness characterlstlc curve of a conventlonal slngle Insu-latlng layer type EL dlsplay devlce and a double Insulatlng layertype EL dlsplay devlce;
F~g. 3 shows the drlvlng voltage waveforms of the EL
dlsplay devlces;
Flg . 4 I S a graph showlng the applled voltage-lumlnes-cent brlghtness characterlstlc curves obtalned by drlvlng the EL
dlsplay devlce shown In Fl9. 1 wlth dc pulse voltages;
F Igs . ~, 6 and 7 are sectlonal vlews showlng other examples of the EL dlsplay devlce accordlng to the Inventlon; and ,~
Flg. 8 Is a partly cutaway perspectlve vlew showing stlll another example.
Flg. 1 shows one embodlment of an EL dlsplay devlce accordlng to the Inventlon. In thls devlce, a pluralIty of seml-conductor strlp electrodes 2 are arranged In parallel on one ~ur-face of a transparent Insulatlng substrate, e.g.~ a glass sub-strate 1. The semlconductlve strlp electrodes 2 are made of zlnc oxlde and have a thlckness o$ 100 nm. An EL layer 3 and an Insu-latlng layer 4 are successlvely formed on one surface of the glass substrate I Includlng the upper sldes of the semlconductor strlp electrodes 2. Formed on the insulatlng layer 4 are a Plu ralIty of strlp electrodes ~ whlch are arranged parallel ~o each other and extend In a dlrectlon Perpendicular to the dlrectlon oF
the semlconductlve strlp electrodes 2. The EL emlttlng layer ~
Is made of zlnc sul$1de actlvated by manganese and It has a spe-clfic manganese content of 0.8 atomlc % and a thIckness of 0.5 ~m. The Insulatlng layer 4 Is made of yttrlum oxlde (Y203) , ~
; , ., and It has a thlckne~s of 0.4 ~ m. The strlp electrodes 5 are made of alumlnum.
-rhe semlconductlve strlp electrodes 2 are formed by placlng the glass substrate 1 In an argon gas of 2 x 10-2 Torr, malntainlng a temperature of 150C, deposltlng zlnc oxlde on the glass substrate 1 at the rate of 10 nm per mlnute for 10 mlnutes by a radlo-frequency sputterlng process and then formlng semlcon-ductive strlp electrodes by the wldely used photollthography technlque. The EL layer 3 Is formed by malntalnlng the glass substrate 1 at 220C, slmultaneously evaporatlng zlnc sul$1de and manganese at the rate of 0.1~ m per mlnute for 5 mlnutes to attaln a glven ratlo therebetween and then subJectlng the same to a heat treatment at ~0C for 2 hours In a vacuum. The Insulat-1~ Ing layer 4 Is formed by the electron-beam evaporatlon o~ yttrlum oxlde and the electrodes 5 are formed by the vacuum evaporatlon of alumlnum.
Wlth thls devlce, when an ac voltage or pulse voltage Is applled selectlvely between the electrodes 2 and 5, the por-tlon of the EL layer 3 enclosed by the selected electrodes emlts llght. Thls llght Is radlated to the outslde malnly through the glass substrate 1. By successlvely applylng slgnal voltages cor-respondlng to In~ormatlon to be d5splayed, to the electrodes 2 and ~, It Is posslble to dlsplay the Informatlon as an Image.
F~g. 2 compares the applled voltage (VA3-lumlnescent brlghtness characterlstlcs obtalned by drlvlng the devlce of Flg.
1 and the two conventlonal types of EL dlsplay devlces wlth an ac pulse voltage (VA) havlng a pulse wldth of 20 sec and a perlod of 10 m sec as shown In ~a) of Flg. 3. I n Flg, 2, curve (a) shows the characterlstlc curve for an EL dlsplay devlce accordlng to the Inventlon and curve (b) shows the characterlstlc curve for a slngle Insulatlng layer type EL dlsplay devlce constructed by replaclng the semlconductlve strlp electrodes 2 wlth transparent electrodes ~ade ot tln contalnlng Indlum oxlde In the devlce of ~%56~3~
the prevlously de~crlbed constructlon. Also, curve (c) In Flg. 2 shows the characterlstlc c~rve for a conventlonal double Insulat-lng layer type EL dlsplay devlce constructed by successlvely formlng an yttrlum oxlde layer of 0.2 ~m thlck. an EL layer made of maganese-actIvated zlnc sulflde and having a thlckness of 0.5 ~m and an yttrlum oxlde layer havlng a thlckness of 0.2 ~m on transparent electrodes and flnally formlng alumlnum electrodes.
As wlll be seen from Flg. 2, the Fl_ dlsplay devlce of thls Inven-tlon Is capable of reduclng the drlve voltage alone wlthout reduclng the lumlnescen-t brlghtness and maklng posslble low-volt-age operatlon of Its drlve clrcult.
F l g . 4 shows the apPlled voltage (VB)-lumlnescent brlghtness characterlstlcs obtalned by applylng a dc pulse volt-1~ age (VB) havlng a pulse wldth of 20 sec and a pulse spaclng of 10 m sec as shown In (b) of Flg. 3 to the EL dlsplay devlce " accordlng to the Inventlon, wlth the curve (a) showlng the char-acterlstlc obtalned by applylng a voltage of a polarlty such that the electrodes 5 become posltlve wlth respect to the semiconduc-tlve strlp electrodes 2 and the curve (b) showlng the character-lstlc obtalned by applylng a voltage of a poiarlty sUch that the semlconductlve strlp electrodes ~ become posltlve wlth respect to the electrodes ~. As wlll be seen from Flg. ~, the EL dlsplay devlce accordlng to the Inventlon could produce a dlsplay wlth
The present Inventlon relates to eiectroluminescent dlsplay devlces and more partlcularly to an elec-trolumlnescent dlsplay devlce havlng a novel constructlon whlch ensures an Improved lumlnescent brlghtness and low voltage drlvlng.
In the past, electrolumlnlescent dlsplay devlces (herelnafter slmply referred to as IEL dlsplay devlces) have been known Includlng EL dlsplay devlces ~Df a double lnsulatlng layer type In whlch the sldes of an electrolumlnescent llght emlttlng layer (herelnafter slmply referred to as an EL layer) are held between Insulatlng layers whlch are In turn held externally between a transparent eiectrode made essentlally of lndlum oxlde (In~03) or tln oxlde (SnO2) and a metal electrode made of alu-mlnum (Al) or the llke and EL dlsplay devlces of a slngle Insu-latlng layer type In whlch an EL layer ls dlrectly formed on atransparent electrode made essentlally of lndlum oxlde or tln oxlde and then an lnsulatlng layer and a metal electrode are suc-cesslvely provlded on the EL layer. If these two types of EL
dlsplay devlces are constructed so that they have the same total lnsulatlng layer thlckness and the same EL emltting thlckness and an ac voltage or pulse voltage ls applled to cause llght emls-slon, the EL dlsplay devlce of the slngle Insulatlng layer type ls lower than the EL dlsplay devlce of the double lnsulatlng layer type ln terms of lumlnescent threshold voltage and also the EL dlsplay devlce of the ciouble lnsulatlng layer type ls hlgher than the EL dlsplay devlce of the slngle lnsulatlng layer type In terms of iumlnescent brlghtness. Thus, the known EL display devlces have had thelr own merlts and demerlts and therefore . there has been a demand for an EL dlsplay devlce whlch has a lower luminescent threshold voltage or ls adapted to be drlven at a lower voltage and whlch also has a hlgher lumlnescent brlghtness.
The present Inventlon provides an EL dlsplay devlce of 3~ the type In whlch energl~lng means apply slgnal voltages corre-spondlng to lnformatlon to an assembly of an EL layer Includlng zlnc sul~ide contalnlng a lumlnescently actlve materla~ and an Insulatlng layer thereby dlsp~aylng the Informatlon In the form of an Image, whereln one of the energlzlng means arranged on the slde of the EL layer Includes a plurallty of semlconductlve elec-trodes contalnlng at least one compound selected from the group conslsts of the chemlcal compounds of Groups ~T ~Z~ or at least one compound selected from the group of chemlcal compounds of Groups 11-~1 and tln oxlde thus ensur5ng a reduced lumlnescent threshold voltage and an Increased lumlnescent brlghtness.
As regards ~roup Il-gl chemlcal compound constltutlng the semlconductor electrodes whlch form one of the energlzlng means, at least one of zlnc oxlde (ZnO), zlnc selenlde (ZnSe), ~Inc tellurIde (ZnTe), zlnc sulfIde (7nS), cadmlum sulfIde (CdS) and cadmlum selenlde (CdSe) Is preferred and partlcularly zlnc oxlde Is preferred most. Also, It Is needless to say that the semlconductor electrodes may be made of at least one of these chemlcal compounds and tln oxlde.
Any one of the heretofore known materials may be used as the lumlnescently actlve materlal added to the zlnc sulflde of the EL layer and It Is only necessary to make the selectlon In accordance wlth the deslred lumlnescent color. Manganese (Mn), copper (Cu), sllver (Ag), alumlnum (Al), terblum (Tb), dysproslum (Dy~, erbium (Er), praseodymlum ~Pr), samarlum (Sm), holmlum (Ho), thullum (Tm) and thelr halIdes may be clted as examples o~
the lumlnescenln~ly actlve materlal.
~he present Inventlon wlll be apparent from the follow-Ing detalled descrlptlon taken In conJunctlon wlth the accompany-lng drawlngs, ~n whlch:-Flg. 1 Is a partly cutaway perspectlve vlew showlng an example o~ an EL dlsplay devlce accordlng to the Inventlon;
~'~S~3~3 F Ig . 2 Is a graph showlng applled voltage-lumlnescent brlghtness character~stlc curves for the EL dlsplay devlce shown In F Ig . 1 I n comparlson wlth the applled voltage-lumlnescent brlghtness characterlstlc curve of a conventlonal slngle Insu-latlng layer type EL dlsplay devlce and a double Insulatlng layertype EL dlsplay devlce;
F~g. 3 shows the drlvlng voltage waveforms of the EL
dlsplay devlces;
Flg . 4 I S a graph showlng the applled voltage-lumlnes-cent brlghtness characterlstlc curves obtalned by drlvlng the EL
dlsplay devlce shown In Fl9. 1 wlth dc pulse voltages;
F Igs . ~, 6 and 7 are sectlonal vlews showlng other examples of the EL dlsplay devlce accordlng to the Inventlon; and ,~
Flg. 8 Is a partly cutaway perspectlve vlew showing stlll another example.
Flg. 1 shows one embodlment of an EL dlsplay devlce accordlng to the Inventlon. In thls devlce, a pluralIty of seml-conductor strlp electrodes 2 are arranged In parallel on one ~ur-face of a transparent Insulatlng substrate, e.g.~ a glass sub-strate 1. The semlconductlve strlp electrodes 2 are made of zlnc oxlde and have a thlckness o$ 100 nm. An EL layer 3 and an Insu-latlng layer 4 are successlvely formed on one surface of the glass substrate I Includlng the upper sldes of the semlconductor strlp electrodes 2. Formed on the insulatlng layer 4 are a Plu ralIty of strlp electrodes ~ whlch are arranged parallel ~o each other and extend In a dlrectlon Perpendicular to the dlrectlon oF
the semlconductlve strlp electrodes 2. The EL emlttlng layer ~
Is made of zlnc sul$1de actlvated by manganese and It has a spe-clfic manganese content of 0.8 atomlc % and a thIckness of 0.5 ~m. The Insulatlng layer 4 Is made of yttrlum oxlde (Y203) , ~
; , ., and It has a thlckne~s of 0.4 ~ m. The strlp electrodes 5 are made of alumlnum.
-rhe semlconductlve strlp electrodes 2 are formed by placlng the glass substrate 1 In an argon gas of 2 x 10-2 Torr, malntainlng a temperature of 150C, deposltlng zlnc oxlde on the glass substrate 1 at the rate of 10 nm per mlnute for 10 mlnutes by a radlo-frequency sputterlng process and then formlng semlcon-ductive strlp electrodes by the wldely used photollthography technlque. The EL layer 3 Is formed by malntalnlng the glass substrate 1 at 220C, slmultaneously evaporatlng zlnc sul$1de and manganese at the rate of 0.1~ m per mlnute for 5 mlnutes to attaln a glven ratlo therebetween and then subJectlng the same to a heat treatment at ~0C for 2 hours In a vacuum. The Insulat-1~ Ing layer 4 Is formed by the electron-beam evaporatlon o~ yttrlum oxlde and the electrodes 5 are formed by the vacuum evaporatlon of alumlnum.
Wlth thls devlce, when an ac voltage or pulse voltage Is applled selectlvely between the electrodes 2 and 5, the por-tlon of the EL layer 3 enclosed by the selected electrodes emlts llght. Thls llght Is radlated to the outslde malnly through the glass substrate 1. By successlvely applylng slgnal voltages cor-respondlng to In~ormatlon to be d5splayed, to the electrodes 2 and ~, It Is posslble to dlsplay the Informatlon as an Image.
F~g. 2 compares the applled voltage (VA3-lumlnescent brlghtness characterlstlcs obtalned by drlvlng the devlce of Flg.
1 and the two conventlonal types of EL dlsplay devlces wlth an ac pulse voltage (VA) havlng a pulse wldth of 20 sec and a perlod of 10 m sec as shown In ~a) of Flg. 3. I n Flg, 2, curve (a) shows the characterlstlc curve for an EL dlsplay devlce accordlng to the Inventlon and curve (b) shows the characterlstlc curve for a slngle Insulatlng layer type EL dlsplay devlce constructed by replaclng the semlconductlve strlp electrodes 2 wlth transparent electrodes ~ade ot tln contalnlng Indlum oxlde In the devlce of ~%56~3~
the prevlously de~crlbed constructlon. Also, curve (c) In Flg. 2 shows the characterlstlc c~rve for a conventlonal double Insulat-lng layer type EL dlsplay devlce constructed by successlvely formlng an yttrlum oxlde layer of 0.2 ~m thlck. an EL layer made of maganese-actIvated zlnc sulflde and having a thlckness of 0.5 ~m and an yttrlum oxlde layer havlng a thlckness of 0.2 ~m on transparent electrodes and flnally formlng alumlnum electrodes.
As wlll be seen from Flg. 2, the Fl_ dlsplay devlce of thls Inven-tlon Is capable of reduclng the drlve voltage alone wlthout reduclng the lumlnescen-t brlghtness and maklng posslble low-volt-age operatlon of Its drlve clrcult.
F l g . 4 shows the apPlled voltage (VB)-lumlnescent brlghtness characterlstlcs obtalned by applylng a dc pulse volt-1~ age (VB) havlng a pulse wldth of 20 sec and a pulse spaclng of 10 m sec as shown In (b) of Flg. 3 to the EL dlsplay devlce " accordlng to the Inventlon, wlth the curve (a) showlng the char-acterlstlc obtalned by applylng a voltage of a polarlty such that the electrodes 5 become posltlve wlth respect to the semiconduc-tlve strlp electrodes 2 and the curve (b) showlng the character-lstlc obtalned by applylng a voltage of a poiarlty sUch that the semlconductlve strlp electrodes ~ become posltlve wlth respect to the electrodes ~. As wlll be seen from Flg. ~, the EL dlsplay devlce accordlng to the Inventlon could produce a dlsplay wlth
2~ the maxlmum brlghtness of 90 nlts by uslng a dc pulse voltage havlng a duty cycle of 1/500 and such a polarlty that the elec-trodes 5 become posltlve wlth respect to the semlconductlve strlp electrodes 2. The reallzatlon of such a hlgh brIghtness is con sldered to be due to the fact that the contact between the seml-conductlve strlp electrodes Z made of zlnc oxlde and the EL layer3 Is excellent thus facllltatln~ the InJectlon of electrons from the semlconductlve strlp electrodes 2 Into the EL layer 3.
Whlle the foregolng example descrlbes the case In whlch the semlconductlve electrodes are made of zlnc oxlde, slmllar effects were obtalned by uslng semlconductlve electrodes made of ~,Z~3~3 zlnc selenlde, zlnc tellurlde, zlnc sulFlde, cadmlum sul-Flde or cadmlum selenlde, any one of these compounds and tln oxlde, zlnc oxlde and tln oxlde, or a comblnatlon of a plurallty of these materlals. It was conflrmed that a semlconductlve layer thlck-ness of 30 nm or over showed good reproduclblllty and efFectlve-ness. In addltlon to Mn, at least one element seiected from the group conslstlng of Cu, Ag, ~1, Tb, Dy, Er, Pr, Sm, Ho, Tm and thelr halldes may be used as the lumlnesclngly actlve materlal and In thls way EL dlsplay devlces of dlfferent lumlnescent col-ors were constructed.
Then, whlle, In the EL dlsplay devlce shown In F/g. 1,the semlconductor strlps serve as one of the two electrodes, where an EL dlsplay devlce has a wlde surface area so that the reslstance of the semlconductlve strlps become so large that It Is no longer negllglble, It Is only necessary to use a conductlve , strlp of a lower reslstance along ~Ith each semlnconductlve strlp.
In other words, as shown In F/~. ~, conductlve strlps 6 havlng good conductlvlty and a very narrow wldth, as compared wlth the semlconductlve strlp electrodes 2 are dlsposed between each semiconductlve strlp electrodes 2 and the glass substrate 1, and thus the semlconductlve electrodes Include a semlconductlve portlon and a conductive portlon provlded by the semlconductlve strlp electrodes 2 and the conductlve strlps 6. The ¢onductlve strlps 6 may, for example, be made of a materl~l havlng a low speclflc reslstance, such as tltanlum nltrlde, gold, platlnum or molybdenum.
Wlth thls constructlon, the presence of conductlve strlps 6 has the effect of reduclng the reslstance of ~he elec-trode formed by the semlconductlve strlp electrodes 2 and the conductlve strlps 6 and make It posslble to reallze an EL dlsplay devlce havlng a large screen wlthout any brlghtness inhomogenelty.
Whlle the foregolng example descrlbes the case In whlch the semlconductlve electrodes are made of zlnc oxlde, slmllar effects were obtalned by uslng semlconductlve electrodes made of ~,Z~3~3 zlnc selenlde, zlnc tellurlde, zlnc sulFlde, cadmlum sul-Flde or cadmlum selenlde, any one of these compounds and tln oxlde, zlnc oxlde and tln oxlde, or a comblnatlon of a plurallty of these materlals. It was conflrmed that a semlconductlve layer thlck-ness of 30 nm or over showed good reproduclblllty and efFectlve-ness. In addltlon to Mn, at least one element seiected from the group conslstlng of Cu, Ag, ~1, Tb, Dy, Er, Pr, Sm, Ho, Tm and thelr halldes may be used as the lumlnesclngly actlve materlal and In thls way EL dlsplay devlces of dlfferent lumlnescent col-ors were constructed.
Then, whlle, In the EL dlsplay devlce shown In F/g. 1,the semlconductor strlps serve as one of the two electrodes, where an EL dlsplay devlce has a wlde surface area so that the reslstance of the semlconductlve strlps become so large that It Is no longer negllglble, It Is only necessary to use a conductlve , strlp of a lower reslstance along ~Ith each semlnconductlve strlp.
In other words, as shown In F/~. ~, conductlve strlps 6 havlng good conductlvlty and a very narrow wldth, as compared wlth the semlconductlve strlp electrodes 2 are dlsposed between each semiconductlve strlp electrodes 2 and the glass substrate 1, and thus the semlconductlve electrodes Include a semlconductlve portlon and a conductive portlon provlded by the semlconductlve strlp electrodes 2 and the conductlve strlps 6. The ¢onductlve strlps 6 may, for example, be made of a materl~l havlng a low speclflc reslstance, such as tltanlum nltrlde, gold, platlnum or molybdenum.
Wlth thls constructlon, the presence of conductlve strlps 6 has the effect of reduclng the reslstance of ~he elec-trode formed by the semlconductlve strlp electrodes 2 and the conductlve strlps 6 and make It posslble to reallze an EL dlsplay devlce havlng a large screen wlthout any brlghtness inhomogenelty.
3~3 In the EL dlsplay devlce shown In F/g. 6, transparent conductlve strlps 8 Is placed between each semlconductlve strlp electrodes 2 and the glass substrate 1. With the electrode 5 formed by the semlnconductlve strlp electrodes 2 and the trans-parent conductlve strlps 8, Its electrlcal conductlvlty Is pro-vlded malnly by the transparent conductlve strlps 8 and thus Its reslstance Is reduced maklng It posslble to reallze an EL dlsplay devlce havlng a large screen.
The EL dlsplay devlce shown In Flg. 7 Is a partlal mod~
IfIcatlon of the constructlon of the devlce shown In Flg. 6. In thls devlce each transparent. conductlve strlp B Is covered by each semlconductlve strlp electrode 2 and the two layers 2 and 8 are formed to have tapered edges.
Due to the fact that the semlconductlve strlp elec-trodes 2 cover the transparent conductlve strlps 8, the con-stltuent elements of the transparent conductlve strlps 8 are pre-vented by the semlconductlve strlp electrodes 2 from dlffuslngInto the EL layer 3 thus effectlvely preventlng any deterioratlon In the characterlstlc of the EL layer 3 due to the constltuent element of the transparent conductlve strlps B. In other words, the transparent conductlve strlps 8 are generally made of oxldes of Indlum and tln so that If the constltuent element Indlum dlf-fuses Into the EL layer 3 whose prlnclpal constltuent Is zlnc sulfIde, thls Indlum serves as a klller In the EL layer 3 and Its lumlnescent characterlstlc Is deterlorated. However, the dlffU-slon of Indlum Is prevented by the presence between the two lay-ers 3 and 8 of the semlconductlve strlp electrodes 2 contalnlngthe compound of the Groups n~
Then, slnce each oF the transparent conductlve strips 8 and the semlconductlve strlp electrodes 2 has Its two edges -~apered, the deterloratlon due to any electrlc fleld concentra-~LZ~ )3~3 tlon at the eiectrode edge portlons l~ very effectl~ely preventedas compared wlth the devlce shown In F l g . 6 .
The EL dlsplay devlce shown In FIg. 8 Is the EL dlsplay devlce of F/g. 6 In whlch the constructlon of the semlconductlve electrodes Is modlfled. In other words, thls devlce repiaces the semlconductlve strlps wlth semlconduct;ve layer 7 Interposed between the g~ass substrate 1 and the transparent conductlve strips 8 on one slde and the EL layer 3. Thls devlce Is advanta-geous In that the operatlon of sellectlvely forming the semlncon-ductlve layer 7 Is elImlnated In tlhe manufacture of the devlce and the devlce can be made easlly. Wlth thls devlce, however, there Is the danger of the semlcon~uctlve layer 7 causlng cross-talk between the transparent conductlve ~trlps 8 and therefore the semlconductlve layer 7 should preferably contaln a materlal whlch Increases the resistance value of the group 11-~1 compound, e.g., llthlum (Ll), thereby satlsfactorlly Increaslng the resls-tance between the transparent conductlve striPs 8. In thls case, the thlckness of the semlconductlve layer 7 Is extremely thln as ZO compared wlth the InterYal between the transparent conductlve strlps 8 and thereFore any Increase In the reslstance value of the semlconductlve layer 7 In Its thlckness dlrectlon due to the addltlon of the sald mater~al can be Ignored.
As descrlbed herelnabove, the EL dlsplay devlce accord-lng to the Inventlon Includes semlconductive layers eontalnlng at least one compound selected from the group conslstlng of cc~-pounds of group ~ or the sald compound and tln oxlde and arranged on one surface of an EL layer thereby reallzlng an EL
dlsplay devlce ensurlng a reduced drlve voltage and an Increased brlghtness. Then, the fact that the use of a low drlve voltage Is sufflclent makes It posslble to use ICs o~ low withstand volt-ages for constructlng a drlve unlt wlth ICs and thus the cost of the EL dlsplay devlce can be reduced. Furtherg thls EL dlsplay 3~ devlce permlts not only an ac voitage drlve but also a dc pulse voltage drlve and thus It has a remarkable utillty value.
~; ~ - 8 -:'~' ' `
The EL dlsplay devlce shown In Flg. 7 Is a partlal mod~
IfIcatlon of the constructlon of the devlce shown In Flg. 6. In thls devlce each transparent. conductlve strlp B Is covered by each semlconductlve strlp electrode 2 and the two layers 2 and 8 are formed to have tapered edges.
Due to the fact that the semlconductlve strlp elec-trodes 2 cover the transparent conductlve strlps 8, the con-stltuent elements of the transparent conductlve strlps 8 are pre-vented by the semlconductlve strlp electrodes 2 from dlffuslngInto the EL layer 3 thus effectlvely preventlng any deterioratlon In the characterlstlc of the EL layer 3 due to the constltuent element of the transparent conductlve strlps B. In other words, the transparent conductlve strlps 8 are generally made of oxldes of Indlum and tln so that If the constltuent element Indlum dlf-fuses Into the EL layer 3 whose prlnclpal constltuent Is zlnc sulfIde, thls Indlum serves as a klller In the EL layer 3 and Its lumlnescent characterlstlc Is deterlorated. However, the dlffU-slon of Indlum Is prevented by the presence between the two lay-ers 3 and 8 of the semlconductlve strlp electrodes 2 contalnlngthe compound of the Groups n~
Then, slnce each oF the transparent conductlve strips 8 and the semlconductlve strlp electrodes 2 has Its two edges -~apered, the deterloratlon due to any electrlc fleld concentra-~LZ~ )3~3 tlon at the eiectrode edge portlons l~ very effectl~ely preventedas compared wlth the devlce shown In F l g . 6 .
The EL dlsplay devlce shown In FIg. 8 Is the EL dlsplay devlce of F/g. 6 In whlch the constructlon of the semlconductlve electrodes Is modlfled. In other words, thls devlce repiaces the semlconductlve strlps wlth semlconduct;ve layer 7 Interposed between the g~ass substrate 1 and the transparent conductlve strips 8 on one slde and the EL layer 3. Thls devlce Is advanta-geous In that the operatlon of sellectlvely forming the semlncon-ductlve layer 7 Is elImlnated In tlhe manufacture of the devlce and the devlce can be made easlly. Wlth thls devlce, however, there Is the danger of the semlcon~uctlve layer 7 causlng cross-talk between the transparent conductlve ~trlps 8 and therefore the semlconductlve layer 7 should preferably contaln a materlal whlch Increases the resistance value of the group 11-~1 compound, e.g., llthlum (Ll), thereby satlsfactorlly Increaslng the resls-tance between the transparent conductlve striPs 8. In thls case, the thlckness of the semlconductlve layer 7 Is extremely thln as ZO compared wlth the InterYal between the transparent conductlve strlps 8 and thereFore any Increase In the reslstance value of the semlconductlve layer 7 In Its thlckness dlrectlon due to the addltlon of the sald mater~al can be Ignored.
As descrlbed herelnabove, the EL dlsplay devlce accord-lng to the Inventlon Includes semlconductive layers eontalnlng at least one compound selected from the group conslstlng of cc~-pounds of group ~ or the sald compound and tln oxlde and arranged on one surface of an EL layer thereby reallzlng an EL
dlsplay devlce ensurlng a reduced drlve voltage and an Increased brlghtness. Then, the fact that the use of a low drlve voltage Is sufflclent makes It posslble to use ICs o~ low withstand volt-ages for constructlng a drlve unlt wlth ICs and thus the cost of the EL dlsplay devlce can be reduced. Furtherg thls EL dlsplay 3~ devlce permlts not only an ac voitage drlve but also a dc pulse voltage drlve and thus It has a remarkable utillty value.
~; ~ - 8 -:'~' ' `
Claims (55)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. An electroluminescent display device comprising an electroluminescent layer including zinc sulfide (ZnS) containing a luminescingly active material, an electrically insulating layer formed on one surface of said electroluminescent layer and first energizing means and second energizing means for applying signal voltages corresponding to an information to be displayed to a multilayer assembly of said electroluminescent emitting layer and said insulating layer whereby displaying said information as an image, characterized in that of said first and second energizing means, said first energizing means arranged on the side of said electroluminescent layer comprises at least a plurality of semi-conductive electrodes, and that said semiconductive electrodes contain one or more chemical compounds selected from the group consisting of chemical compounds of group II-VI.
2. An electroluminescent display device according to claim 1, characterized in that said first energizing means com-prises a semiconductive layer and a plurality of electrical con-ductors disposed in said semiconductive layer, and that said semiconductive layer is placed in contact with said electrolumi-nescent emitting layer.
3. An electroluminescent display device according to claim 1, characterized in that said first energizing means com-prises a plurality of parallel semiconductive strips and an elec-trical conductor provided for each of said semiconductive layers, and that said semiconductive layers are placed in contact with said electroluminescent emitting layer.
4. An electroluminescent display device according to claim 1, characterized in that said first energizing means com-prises a plurality of parallel semiconductive strips and a trans-parent electrical conductive layer provided for each of said semiconductive layers, and that said semiconductive layers are placed in contact with said electroluminescent emitting layer.
5. An electroluminescent display device according to claim 1, characterized in that said first energizing means com-prises a plurality of parallel electrical conductive strips and a semiconductive layer covering each of said electrical conductive strips, and that said semiconductive layers are placed in contact with said electroluminescent emitting layer.
6. An electroluminescent display device according to claim 1, characterized in that said first energizing means com-prises a plurality of parallel transparent electrical conductive strips and a semiconductive layer covering each of said transpar-ent electrical conductive strips, and that said semiconductive layers are placed in contact with said electroluminescent emit-ting layer.
7. An electroluminescent display device according to claim 1, 2 or 3, characterized in that each of said semiconduc-tive layers has tapered edges, and that one surface of each said semiconductive layer on said electroluminescent emitting layer side has an area smaller than an area of the other surface thereof.
8. An electroluminescent display device according to claim 1, 2 or 3, characterized in that each said semiconductive layer contains at least one chemical compound selected from the group consisting of chemical compounds of Groups II-VI and tin oxide (SnO2).
9. An electroluminescent display device according to claim 1, 2 or 3, characterized in that each said semiconductive layer contains at least one chemical compound selected from the chemical compound group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cad-mium sulfide (CdS) and cadmium telluride (CdTe).
10. An electroluminescent display device according to claim 1, 2 or 3, characterized in that each said semiconductive layer contains at least one chemical compound selected from the chemical compound group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cad-mium sulfide (CdS) and cadmium telluride (CdTe) and tin oxide (SnO2).
11. An electroluminescent display device according to claim 1, 2 or 3, characterized in that said second energizing means comprises a plurality of electrical conductive strips, and that conductive strips are arranged on said insulating layer.
12. An electroluminescent display device according to claim 1, 2 or 3, characterized in that each said semiconductive layer has a thickness of at least 30 nm.
13. An electroluminescent display device comprising a multilayer assembly including at least a first electrode, an electroluminescent emitting layer including zinc sulfide (ZnS) containing a luminescent active material and placed in contact with said first electrode, an insulating layer placed in contact with said electroluminescent emitting layer and a second elec-trode placed in contact with said insulating layer, and a sup-porting base supporting said multilayer assembly on one surface thereof whereby applying signal voltages corresponding to an information to be displayed across said first and second elec-trodes and thereby displaying said information as an image, char-acterized in that said first electrode includes at least a plu-rality of semiconductive strips, and that said semiconductive strips contain one or more chemical compounds selected from the group consisting of chemical compounds of Groups II-VI.
14. An electroluminescent display device according to claim 13, characterized in that one or the other of said first and second electrodes is arranged on a surface of said supporting base.
15. An electroluminescent display device according to claim 13, characterized in that said first electrode comprises a semiconductive strip and a plurality of electrical conductors disposed In said semiconductive strip, and that said semiconduc-tive strip is placed in contact with said electroluminescent emitting layer.
16. An electroluminescent display device according to claim 13, characterized in that said first electrode comprises a plurality of parallel semiconductive strips and an electrical conductor provided for each of said semiconductive strips, and that said semiconductive strips are placed in contact with said electroluminescent emitting layer.
17. An electroluminescent display device according to claim 13, characterized in that said first electrode comprises a plurality of parallel semiconductive strips and a transparent electrical conductor layer is provided for each of said semicon-ductive strips, and that said semiconductive strips are placed in contact with said electroluminescent emitting layer.
18. An electroluminescent display device according to claim 13, characterized in that said first electrode comprises a plurality of parallel electrical conductive strips and a semicon-ductive layer covering each of said electrical conductive strips, and that said semiconductive layers are placed in contact with said electroluminescent emitting layer.
19. An electroluminescent display device according to claim 13, characterized in that said first electrode comprises a plurality of parallel transparent electrical conductive strips and a semiconductive layer covering each of said electrical con-ductive strips, and that said semiconductive layers are placed in contact with said electroluminescent emitting layer.
20 . An electroluminescent display device according to claim 13, 14 or 15, characterized in that each of said semicon-ductive layers has tapered edges, and one surface of each said semiconductive layer on said electroluminescent emitting layer side has an area smaller than an area of the other surface thereof.
21. An electroluminescent display device according to claim 13, 14 or 15, characterized in that each said semiconduc-tive layer contains at least one chemical compound selected from the group consisting of chemical compounds of Groups II-VI and tin oxide (Sn2).
22. An electroluminescent display device according to claim 13, 14 or 15, characterized in that each said semiconduc-tive layer contains at least one chemical compound selected from the chemical compound group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cad-mium sulfide (CdS) and cadmium telluride (CdTe).
23. An electroluminescent display device according to claim 13, 14 or 15, characterized in that each said semiconduc-tive layer contains at least one chemical compound selected from the chemical compound group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cad-mium sulfide (CdS) and cadmium telluride (CdTe) and tin oxide (SnO2).
24. An electroluminescent display device according to claim 13, 14 or 15, characterized in that each said semiconduc-tive layer has a thickness of at least 30 nm.
25. An electroluminescent display device suitable for ac and unipolar pulse voltage operation, comprising: a transpar-ent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed, wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes at least one semiconduc-tive electrode which contacts said electroluminescent layer and is comprised of a semiconductive material containing at least one chemical compound selected from the group consisting of the chem-ical compounds of Groups II-VI, and wherein said second ener-gizing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
26. An electroluminescent display device according to claim 25, wherein each said at least one semiconductive electrode includes a semiconductive portion and a conductive portion having a conductivity higher than that of said semiconductive portion, said semiconductive portion being interposed between said conduc-tive portion and said electroluminescent layer.
27. An electroluminescent display device according to claim 26, wherein said semiconductive portions are a single semi-conductive layer and said conductive portions are a plurality of conductive strips arranged in parallel to one another.
28. An electroluminescent display device according to claim 26, wherein said semiconductive portions are a plurality of semiconductive strips arranged in parallel to one another, and wherein said conductive portions are a plurality of conductive strips arranged in parallel to one another, one conductive strip being provided for each of said semiconductive strips.
29. An electroluminescent display device according to claim 28, wherein said plurality of conductive strips are a plu-rality of transparent conductive strips.
30. An electroluminescent display device according to claim 28, wherein each of said semiconductive strips covers one of said conductive strips.
31. An electroluminescent display device according to claim 29, wherein each of said semiconductive strips covers one of said conductive strips.
32 . An electroluminescent display device according to claim 30, wherein each of said semiconductive strips has tapered edges so that the surface thereof which contacts said electrolu-minescent layer has a surface area which is smaller than the sur-face area of the surface thereof which contacts said transparent substrate.
33. An electroluminescent display device according to claim 31, wherein each of said semiconductive strips has tapered edges so that the surface thereof which contacts said electrolu-minescent layer has a surface area which is smaller than the sur-face area of the surface thereof which contacts said transparent substrate.
34. An electroluminescent display device according to claim 25, wherein said semiconductive material comprising said at least one semiconductive layer contains tin oxide and at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI.
35. An electroluminescent display device according to claim 25, wherein said semiconductive material comprising said at least one semiconductive electrode contains tin oxide and at least one chemical compound selected from the group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cadmium sulfide (CdS), and cadmium telluride (CdTe).
36. An electroluminescent display device according to claim 25, wherein said semiconductive material comprising said at least one semiconductive electrode consists of at least one chem-ical compound selected from the group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cadmium sulfide (CdS), cadmium telluride (CdTe) and tin oxide (SnO2).
37. An electroluminescent display device according to claim 25, wherein said second energizing means comprises at least one electrically conductive electrode arranged on said insulating layer.
38. An electroluminescent display device according to claim 37 wherein said at least one electrically conductive elec-trode is a plurality of conductive strips which are arranged in parallel to one another, and wherein said at least one semicon-ductive electrode comprises a plurality of semiconductive strips which are arranged in parallel to one another and are arranged perpendicularly to said plurality of conductive strips.
39. An electroluminescent display device according to claim 25, wherein said at least one semiconductive electrode has a thickness of at lest 30 nm.
40. An electroluminescent display device suitable for ac and unipolar pulse voltage operation, comprising: a transpar-ent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed, wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes at least one semiconduc-tive electrode, each said at least one semiconductive electrode consisting of a semiconductive portion in combination with a transparent conductive portion, said semiconductive portion hav-ing a conductivity higher than that of said electroluminescent layer, said transparent conductive portion having a conductivity higher than that of said semiconductive portion, said semiconduc-tive portion contacting said electroluminescent layer, being interposed between said conductive portion and said electrolumi-nescent layer, being arranged so as to substantially cover said transparent conductive portion, and being a semiconductive mate-rial consisting essentially of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI, and wherein said second energizing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
41. A An electroluminescent display device according to claim 40, wherein said semiconductive material consists of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI.
42. An electroluminescent display device according to claim 40, wherein a plurality of semiconductive electrodes are provided In which said semiconductive portions are a plurality of semiconductive strips arranged in parallel to one another, and said transparent conductive portions are a plurality of conduc-tive strips arranged in parallel to one another, one conductive strip being provided for each of said semiconductive strips.
43. An electroluminescent display device according to claim 40, wherein said semiconductive material consists of at least one chemical compound selected from the group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cadmium sulfide (CdS), and cadmium telluride (CdTe).
44. An electroluminescent display device according to claim 40, wherein said transparent conductive portion consists of lndium oxide doped with tin.
45. An electroluminescent display device according to claim 40, wherein said second energizing means comprises at least one electrically conductive electrode arranged on said insulating layer.
46. An electroluminescent display device according to claim 40, wherein said semiconductive portion has a thickness of at least 30 nm.
47. An electroluminescent display device suitable for ac and unipolar pulse voltage operation, comprising: a transpar-ent electrically Insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed; wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes a single semiconductive electrode consisting of a single semiconductive layer in combina-tion with a plurality of transparent conductive strips, said sin-gle semiconductive layer having a conductivity higher than that of said electroluminescent layer, contacting said electrolumines-cent layer, and being a semiconductive material consisting essen-tially of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI, said plu-rality of transparent conductive strips being arranged in paral-lel to one another and having a conductivity higher than that of said single semiconductive layer, wherein said second energizing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
48. An electroluminescent display device according to claim 47, wherein said semiconductive material consists of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI.
49. An electroluminescent display device according to claim 47, wherein said semiconductive material consists of at least one chemical compound selected from the group consisting of zinc oxide (ZnO), zinc selenide (ZnSe), zinc telluride (ZnTe), zinc sulfide (ZnS), cadmium sulfide (CdS), and cadmium telluride (CdTe).
50. An electroluminescent display device according to claim 47, wherein said transparent conductive portion consists of lndium oxide doped with tin.
51. An electroluminescent display device according to claim 47, wherein said second energizing means comprises at least one electrically conductive electrode arranged on said insuiating layer.
52. An electroluminescent display device according to claim 28, wherein said second energizing means comprises a plu-rality of conductive strip electrodes arranged In Parallel to one another, and wherein said plurality of strip electrodes are arranged perpendicularly to said plurality of semiconductive electrodes.
53. An electroluminescent display device suitable for ac and unipolar pulse voltage operation comprising: a transpar-ent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically Insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed, wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes at least one semiconduc-tive electrode, each said at least one semiconductive electrode consisting of a semiconductive portion in combination with a transparent conductive portion, said transparent conductive por-tion having a conductivity higher than that of said semiconduc-tive portion, said semiconductive portion contacting said elec-troluminescent layer, being interposed between said conductive portion and said electroluminescent layer, being arranged so as to substantially cover said transparent conductive portion, and being a semiconductive material consisting essentially of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI, and wherein said second energizing means is arranged on said insulating layer on the sur-face thereof opposite said electroluminescent layer.
54. An electroluminescent display device suitable for ac and unipolar pulse voltage operation, comprising: a transpar-ent electrically insulating substrate; an electroluminescent layer comprised of zinc sulfide (ZnS) and at least one luminesc-ingly active material; an electrically insulating layer formed on one surface of said electroluminescent layer; and first and sec-ond energizing means for applying signal voltages across said electroluminescent layer and said insulating layer corresponding to information to be displayed; wherein said first energizing means is interposed between said transparent substrate and said electroluminescent layer, and includes a single semiconductive electrode consisting of a single semiconductive layer in combina-tion with a plurality of transparent conductive strips, said sin-gle semiconductive layer contacting said electroluminescent layer and being a semiconductive material consisting essentially of at least one chemical compound selected from the group consisting of the chemical compounds of Groups II-VI, said plurality of trans-parent conductive strips being arranged in parallel to one another and having a conductivity higher than that of said single semiconductive layer, wherein said second energizing means is arranged on said insulating layer on the surface thereof opposite said electroluminescent layer.
55. An electroluminescent display device according to claim 42, wherein said second energizing means comprises a plu-rality of conductive strip electrodes arranged in parallel to one another, and wherein said plurality of conductive strip elec-trodes are arranged perpendicularly to said plurality of semicon-ductive electrodes.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP50678/83 | 1983-03-25 | ||
| JP58050678A JPS59175593A (en) | 1983-03-25 | 1983-03-25 | Electroluminescent display unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1250038A true CA1250038A (en) | 1989-02-14 |
Family
ID=12865589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000445263A Expired CA1250038A (en) | 1983-03-25 | 1984-01-13 | Electroluminescent display device |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS59175593A (en) |
| CA (1) | CA1250038A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS61193396A (en) * | 1985-02-21 | 1986-08-27 | 株式会社村田製作所 | Thin film el element |
| JPS61198592A (en) * | 1985-02-27 | 1986-09-02 | 株式会社村田製作所 | Thin film el element |
| JPS62218474A (en) * | 1986-03-19 | 1987-09-25 | Futaba Corp | Thin-film electroluminescence element |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5812996B2 (en) * | 1977-06-07 | 1983-03-11 | 双葉電子工業株式会社 | electroluminescence device |
| JPS5857288A (en) * | 1981-09-30 | 1983-04-05 | 日本精機株式会社 | Field light emitting element |
| JPS59154793A (en) * | 1983-02-22 | 1984-09-03 | 日本電気株式会社 | Thin film el element |
| JPH066767B2 (en) * | 1986-07-03 | 1994-01-26 | 株式会社神戸製鋼所 | Ti-based alloy with excellent neutron absorption |
-
1983
- 1983-03-25 JP JP58050678A patent/JPS59175593A/en active Granted
-
1984
- 1984-01-13 CA CA000445263A patent/CA1250038A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59175593A (en) | 1984-10-04 |
| JPH0516158B2 (en) | 1993-03-03 |
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