WO1997038347A1 - Eclairage par transmission pour afficheur a cristaux liquides - Google Patents

Eclairage par transmission pour afficheur a cristaux liquides Download PDF

Info

Publication number
WO1997038347A1
WO1997038347A1 PCT/GB1997/000939 GB9700939W WO9738347A1 WO 1997038347 A1 WO1997038347 A1 WO 1997038347A1 GB 9700939 W GB9700939 W GB 9700939W WO 9738347 A1 WO9738347 A1 WO 9738347A1
Authority
WO
WIPO (PCT)
Prior art keywords
light emitting
display according
substrate
light
electrode layer
Prior art date
Application number
PCT/GB1997/000939
Other languages
English (en)
Inventor
Mark Gostick
Original Assignee
Cambridge Display Technology Limited
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
Priority claimed from GBGB9607434.9A external-priority patent/GB9607434D0/en
Application filed by Cambridge Display Technology Limited filed Critical Cambridge Display Technology Limited
Priority to GB9722791A priority Critical patent/GB2314665B/en
Publication of WO1997038347A1 publication Critical patent/WO1997038347A1/fr

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133603—Direct backlight with LEDs

Definitions

  • the present invention relates to the use of organic light emitting devices (LEDs) as backlights for liquid crystal displays (LCDs) .
  • LEDs organic light emitting devices
  • LCDs liquid crystal displays
  • Liquid crystal materials are very widely used in display cells, working as a light valve. Their principle of operation is well known. LCDs are purely passive devices, and can only be used to switch, i.e., transmit, block or partially transmit, light that comes from another source.
  • the source of light that is intended to be used will depend on the application of the display, but the LCD will broadly be one of: reflective - where incident light is reflected by a mirror situated behind a rear polariser on the LCD; transflective - where a partially opaque/partially reflective coating is applied to the rear polariser which will reflect incident light when conditions are bright enough, but will also allow light provided by a backlight mounted behind the LCD to pass through the coating and so allow the LCD to be read; or transmissive - where all the light switched by the LCD is supplied from a backlight.
  • a semi-opaque film is applied to the back of the rear polariser on the LCD, and then a light source is additionally coupled to the semi-opaque film.
  • This light source could for example involve the use of inorganic electroluminescence (IEL) or discrete LEDs combined with waveguides.
  • LEDs as backlights are generally preferred because they are driven from a dc power source at voltages which are normally available within the product in which the LCD is incorporated.
  • IEL backlights could present a more attractive option because they supply a very uniform light output which lends a good appearance to the LCD and they have a very good form factor, being both thin and lightweight.
  • IEL has the disadvantage, however, of being required to be driven by a relatively high voltage ac source, e.g., 90V at 400Hz, which is not normally available and requires an inverter to be built into the product. This is expensive and would require space within the product, eliminating the form factor advantage of the IEL backlight.
  • the inverter can also generate electromagnetic radiation which can cause problems depending on the application.
  • the electroluminescent layer in the IEL device is relatively thick, e.g., of the order of lOO ⁇ m.
  • a display comprising a light modulator defining between a transmissive rear support element and a transmissive front support element a plurality of selectively addressable regions which can be switched between at least an opaque state and a transmissive state, and a light emitting device arranged adjacent the light modulator and fixed to the same comprising a substrate on which is formed a continuous first electrode layer, a continuous light emitting layer and a second electrode layer which extends continuously over the light emitting layer to encapsulate an active area of the light emitting device.
  • a transflective LCD can easily be made m this fashion, where the second electrode layer is reflective.
  • the rear support element carries an optical polariser to which is secured the substrate of the light emitting device.
  • the substrate of the light emitting device itself can constitute the optical polariser for the light modulator.
  • the light emitting device may be fixed to the light modulator by laminating or bonding, or by securing with edge clips .
  • the light modulator has an array of selectively addressable regions (pixels) organised in rows and columns .
  • addressing circuitry comprising column drive circuitry for applying, for each selected row, data voltages on selected ones of column electrodes, and row addressing circuitry for sequentially addressing rows of pixels.
  • the light emitting layer comprises a semiconductive conjugated polymer such as polyphenylenevmylene (PPV) or its derivatives.
  • a semiconductive conjugated polymer such as polyphenylenevmylene (PPV) or its derivatives.
  • PSV polyphenylenevmylene
  • the light emitting layer can take the form of an organic molecular film which, when excited, emits light. Suitable organic molecular films are disclosed in CW. Tang, S.A. Van Slyke and CH. Chen, Journal of Applied Physics, 65, 3610 (1989) .
  • organic LEDs can be very susceptible to moisture and oxygen, good encapsulation is important for longevity of the devices.
  • the second electrode layer is formed of a material which is a barrier to water and oxygen.
  • the light emitting device can be formed on a flexible substrate, since where the rear support element of the light modulator is rigid, the flexible substrate of the light emitting device is thus supported.
  • the light emitting layer When the light emitting layer is a semiconductive conjugated polymer, it emits light when electrically excited. Electrical excitation takes place by application of a voltage between the electrode layers on either side of the light emitting layer, which causes charge carriers of opposite types to be injected into the light emitting layer These charge carriers recombine and decay radiatively to cause light to be emitted from the light emitting layer.
  • an additional polymer layer can be included to act as a charge transport layer or an additional light emitting layer
  • the first electrode layer can constitute an anode of indium tin oxide, while the second electrode layer can constitute a cathode of aluminium.
  • the second electrode layer could be magnesium, calcium or an alloy of these materials with a more stable but higher work function metal.
  • the second electrode layer is formed of a material having a work function of less than 4.2eV.
  • a method of making a display comprising: forming a first electrode layer on a substrate; forming a layer of a light-emissive material onto the first electrode layer; forming a second electrode layer of a material which is a barrier to water and oxygen over the light-emissive material to encapsulate an active area of the light-emissive material; securing the substrate to a light modulator defining between a transmissive rear support element and a transmissive front support element a plurality of selectively addressable regions switchable between at least an opaque state and a transmissive state.
  • a method for making a transflective LCD with an efficient backlight by laminating or bonding an organic LED to the surface of the rear polariser on an LCD, where the organic LED is fabricated on a substrate which is essentially impermeable to oxygen and water.
  • a transflective LCD structure with an efficient backlight where a single substrate is used as a carrier for the rear polariser for a transmissive LCD and as a substrate for an organic LED.
  • Figure 1 is a diagrammatic side view of a known LCD
  • Figure 2 is a section through a light emitting structure
  • Figure 3 is a sketch of a structure according to one embodiment of the present invention.
  • Figure 4 is a sketch of a structure according to a second embodiment of the present invention.
  • Figure 5 is a sketch of a structure according to a third embodiment of the present invention.
  • Figure 6 shows the structure of Figure 3 with associated control circuitry.
  • Figure 1 illustrates a known liquid crystal display structure.
  • a layer 4 of liquid crystal material is sandwiched between two glass substrates la, lb.
  • On the first glass substrate la are defined row conducting electrodes 2 in contact with the liquid crystal layer 4.
  • On the second glass substrate lb are defined column conducting electrodes 3 in contact with the liquid crystal layer 4. To allow transmission of light through the LCD, these electrodes are typically transparent.
  • the row electrodes 2 extend horizontally and the column electrodes 3 extend vertically. Where the row and column electrodes 2, 3 overlap, pixels are defined in the liquid crystal layer 4.
  • These pixels constitute addressable regions which can be controlled by voltages applied to the row and column electrodes 2, 3 so as to be transmissive (i.e., to transmit light) or to be opaque (i.e., to block light) .
  • the state of the pixels depends on the magnitude of the electric fields applied between the row and column electrodes 2, 3 at the point of overlap defining the respective pixels.
  • a polariser 10 in the form of a coated plastic film is bonded to the rear surface of the first glass substrate la and covered by a semi-opaque film 5. Behind the polarizer 10, a backlight 18 is located, which is turned on to supply illumination when background conditions are not bright enough. When background conditions are bright enough, the semi-opaque film 5 acts as a reflector to reflect ambient light, and the backlight 18 is not then needed.
  • a similar polariser is bonded to the front surface of the second glass substrate lb but is not shown.
  • Figure 1 however suffers from the disadvantages already discussed, where the backlight 18 is a plurality of discrete LEDs or uses IEL technology.
  • Figure 3 illustrates an LCD with an improved backlight in the form of an organic LED.
  • the conventional backlight 18 and semi-opaque film 5 have been removed from the structure of Figure 1, so that the LCD has become a transmissive LCD, and replaced with an organic LED as a backlight 8.
  • the structure of the organic LED is shown in Figure 2.
  • the LED 8 is made on a glass substrate 6, which carries a transparent indium tin oxide (ITO) layer 7 with a resistivity of 30 ohms/square.
  • ITO transparent indium tin oxide
  • ITO layer 7 On top of ITO layer 7 is a 500 Angstrom layer of polyphenylenevmylene (PPV) 11 which has been spin coated as a precursor and thermally converted to form the polymer. On top of PPV layer 11 a 500 Angstrom layer 12 of Alq 3 is sublimed. An aluminium electrode layer 13 is then evaporated on top of the Alq 3 layer 12.
  • the ITO layer 7 has been etched away from an area 7a 1mm wide around the edge of the substrate 6 prior to the deposition of subsequent layers A physical mask was used to prevent deposition of the Alq 3 layer 12 outside this area.
  • the aluminium electrode layer 13 is subsequently deposited across the whole substrate area and so encapsulates the whole active electronic area.
  • the LCD and organic LED backlight of Figure 3 were then set up and run at the same level of brightness achieved by the previous experiment.
  • the power consumed was 50mW which is 37% of the power required for the conventional backlight 18, and at the same time a more uniform appearance was provided.
  • the metallic nature of the rear electrode 13 of the organic LED 8 means that incident light is reflected back through the LCD, combining the functions of reflector and backlight into one component.
  • the light emitting layer or layers can be deposited in a continual process such as blade coating or reel to reel coating, and then the top electrode can also be deposited by a continual process such as sputtering.
  • This enables the fabrication of large areas of organic LED and reduces the manufacturing cost.
  • the materials used as the light emitting layer(s) are sensitive to water and oxygen, whose presence can speed up the degradation of the light output of the device. A requirement for good continuous operation of the backlights is therefore good encapsulation of the active layers against this ingress.
  • One of the most effective barriers is a pinhole free metal or metal oxide film, such as aluminium.
  • the structure of Figure 3 has a continuous aluminium film as the top electrode 13, which in addition to providing a reflective rear layer, also has the advantage of providing an efficient barrier to the ingress of water and oxygen into the device.
  • a substrate which is transparent, carries a transparent electrode and is flexible enough to allow it to pass through the path of the coating equipment .
  • Typical substrates are PET coated with an ITO electrode, but many other thermoplastics and electrode materials can also be used, such as tin oxide, polycarbonates and polyethylene napthalate.
  • the thermoplastic substrates used do not typically provide a suitable barrier to water and oxygen for the purposes of organic LED operation.
  • the ITO layer on top of the thermoplastic would provide an effective barrier, in the same way as the top electrode.
  • ITO is fairly brittle and is deposited on top of a soft material and this combination is repeatedly bent during processing. This leads to cracking of the ITO layer which reduces the integrity of the ITO layer as a barrier layer.
  • a major drawback of organic LEDs fabricated on flexible substrates has therefore been the lack of an effective oxygen and water barrier for the substrate side of the device, which has led to poor device lifetimes.
  • Glass can provide a suitable encapsulation to give extended lifetimes, but does not have the necessary flexibility for m-lme processing.
  • Figure 4 shows an organic LED backlight which has substantially the same structure as the device shown in Figure 3 except that the substrate 6' is made from flexible PET rather than glass.
  • the flexible substrate 6 ' of the organic LED is attached to the polariser 10 on the transmissive LCD cell 9.
  • the LED 8' is bonded to the rear polariser 10 on the LCD cell 9 using a cyano- acrylate adhesive 14.
  • the power consumed by the backlight to give the same illumination is less, making the device more efficient than conventional backlighting systems .
  • Figure 5 illustrates another embodiment of the present invention.
  • the rear polariser as the substrate for the organic LED, it is possible to further integrate the organic LED and the LCD cell.
  • FIG. 5 shows the structure of an organic LED, essentially the same as in Figure 1, with the exception that the rear polariser 10' for the LCD cell 9 is used as the substrate.
  • the layer structure is made up as in the embodiment of Figure 3.
  • An ITO layer 7 is sputtered on top of the polariser 10' .
  • On top of the ITO layer 7 is a 500 Angstrom layer of polyphenylenevinylene (PPV) 11 which has been spin coated as a precursor and thermally converted to form the polymer.
  • PPV layer 11 On top of PPV layer 11 a 500 Angstrom layer of Alq 3 12 is sublimed.
  • An aluminium electrode layer 13 is then evaporated on top of the Alq 3 layer 12.
  • PPV polyphenylenevinylene
  • the ITO layer 7 has been etched away from an area 1mm wide around the edge of the polariser 10' prior to the deposition of subsequent layers. A physical mask was used to prevent deposition of Alq 3 outside of this area.
  • the aluminium electrode layer 13 is subsequently deposited across the whole substrate area and so encapsulates the whole active electronic area. When an electric field is applied across the electrode layers 7, 13 which exceeds the charge injection threshold, light is emitted from the PPV layer 11.
  • This composite polariser/backlight is then bonded or laminated to an LCD cell 9, which has another, conventional polariser (not shown) attached to its front surface.
  • the intimate contact with which the polariser 10 ' is attached to the glass of the LCD cell provides an encapsulation for the substrate of the organic LED and so allows the backlight to have a useful operational and storage lifetime while at the same time having manufacturing cost advantages over conventional backlight assemblies.
  • Figure 6 illustrates the structure of Figure 3 together with its associated drive and addressing circuitry.
  • the addressing circuitry comprises row addressing circuitry 17 for selectively addressing row electrodes 2 of the LCD and column drive circuitry 21 for selectively applying the required voltage to the column electrodes 3.
  • An image data store 23 holds image data for controlling the column drive circuitry 21.
  • a clock circuit 19 generates a clock signal which controls the timing of the signals output from the column drive circuitry 21. It also controls the timing of the row addressing circuitry 17.
  • Reference numeral 15 denotes a voltage supply for the electrode layers 7, 13 of the backlight.
  • a switch 22 is provided for selectively turning the backlight on and off depending on the level of ambient light. For bright conditions, the backlight is not required. In that case, the rear electrode layer 13 will act as a reflector to form a transflective LCD structure. However, in dim light, the backlight can be turned on so that the LCD acts as a transmissive LCD.
  • Organic electroluminescent elements especially those incorporating EL polymers are well suited to application as backlights for LCDs in general and transflective LCDs in particular.
  • the fact that they incorporate a metal electrode on top of thin organic layers means that when the organic LED is not energised, it is reflective.
  • an organic LED is used in place of the reflective film or semi- opaque film at the back of an LCD it will take the place of the reflector in conditions of high ambient light when the LED is not energised and will act as a backlight when ambient light levels are low.
  • This means that the backlight can be operated at low output and still give the same brightness at the front of the LCD, which means that battery life of the product into which the device is incorporated can be extended.

Abstract

L'invention concerne un afficheur comprenant un modulateur de lumière qui définit, entre un élément de support arrière transmissif et un élément de support avant de transmission, une pluralité de zones sélectivement adressables qui peuvent basculer au moins d'un état opaque à un état de transmission, et un dispositif émetteur de lumière (8), adjacent au modulateur de lumière (9) et fixé sur ce dernier. Ledit dispositif émetteur de lumière (8) comprend un substrat (6) sur lequel sont formées une première couche électrode (7) continue, une couche émettrice de lumière continue (11) et une seconde couche électrode (13), qui s'étend sans interruption au-dessus de la couche émettrice de lumière (11) de sorte à englober une zone active dudit dispositif émetteur de lumière (8).
PCT/GB1997/000939 1996-04-10 1997-04-02 Eclairage par transmission pour afficheur a cristaux liquides WO1997038347A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB9722791A GB2314665B (en) 1996-04-10 1997-04-02 Efficient backlighting for lcds

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
GB9607434.9 1996-04-10
GBGB9607434.9A GB9607434D0 (en) 1996-04-10 1996-04-10 Efficient backlighting for lcd's
GB9615937.1 1996-07-30
GBGB9615937.1A GB9615937D0 (en) 1996-04-10 1996-07-30 Efficient backlighting for LCDs

Publications (1)

Publication Number Publication Date
WO1997038347A1 true WO1997038347A1 (fr) 1997-10-16

Family

ID=26309088

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1997/000939 WO1997038347A1 (fr) 1996-04-10 1997-04-02 Eclairage par transmission pour afficheur a cristaux liquides

Country Status (1)

Country Link
WO (1) WO1997038347A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999054780A1 (fr) * 1998-04-17 1999-10-28 Cambridge Display Technology Ltd. Ecrans retroeclaires
EP1046944A2 (fr) * 1999-04-13 2000-10-25 Mannesmann VDO Aktiengesellschaft Dispositif LCD auto éclairé
EP1111966A2 (fr) * 1999-12-22 2001-06-27 General Electric Company Dispositif d'affichage luminescent et méthode pour la fabrication
WO2004077137A1 (fr) * 2003-02-21 2004-09-10 Universal Display Corporation Afficheur transflectif ayant une oled d'eclairage en arriere-plan
US7116308B1 (en) 1998-06-19 2006-10-03 Cambridge Display Technology Limited Backlit displays
DE202005011574U1 (de) * 2005-07-22 2006-11-23 Aeg Gesellschaft für Moderne Informationssysteme mbH Flüssigkristallanzeige
US7576496B2 (en) 1999-12-22 2009-08-18 General Electric Company AC powered OLED device
US11488545B2 (en) 2007-06-13 2022-11-01 Interdigital Madison Patent Holdings, Sas Device for displaying images comprising two modulation stages

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3037224A1 (de) * 1980-10-02 1982-04-29 Philips Patentverwaltung Gmbh, 2000 Hamburg Elektrooptische anzeigeeinheit
JPS58221828A (ja) * 1982-06-18 1983-12-23 Sharp Corp 表示装置
JPS5937530A (ja) * 1982-08-27 1984-03-01 Hitachi Ltd 液晶表示装置
US4775820A (en) * 1984-07-31 1988-10-04 Canon Kabushiki Kaisha Multilayer electroluminescent device
EP0701290A1 (fr) * 1994-09-12 1996-03-13 Motorola, Inc. Diodes électroluminiscentes organiques avec alignement de molécules et procédé de fabrication

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3037224A1 (de) * 1980-10-02 1982-04-29 Philips Patentverwaltung Gmbh, 2000 Hamburg Elektrooptische anzeigeeinheit
JPS58221828A (ja) * 1982-06-18 1983-12-23 Sharp Corp 表示装置
JPS5937530A (ja) * 1982-08-27 1984-03-01 Hitachi Ltd 液晶表示装置
US4775820A (en) * 1984-07-31 1988-10-04 Canon Kabushiki Kaisha Multilayer electroluminescent device
EP0701290A1 (fr) * 1994-09-12 1996-03-13 Motorola, Inc. Diodes électroluminiscentes organiques avec alignement de molécules et procédé de fabrication

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN vol. 8, no. 137 (P - 282)<1574> 26 June 1984 (1984-06-26) *
PATENT ABSTRACTS OF JAPAN vol. 8, no. 79 (P - 267)<1516> 11 April 1984 (1984-04-11) *
V.L.COLVIN ET AL.: "LIGHT-EMITTING DIODES MADE FROM CADMIUM SELENIDE NANOCRYSTALS AND A SEMICONDUCTING POLYMER", NATURE, vol. 370, no. 6488, 4 August 1994 (1994-08-04), pages 354 - 357, XP000466647 *

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999054780A1 (fr) * 1998-04-17 1999-10-28 Cambridge Display Technology Ltd. Ecrans retroeclaires
US7402091B2 (en) 1998-06-19 2008-07-22 Cambridge Display Technology Ltd. Backlit displays including organic light-emissive material
US7116308B1 (en) 1998-06-19 2006-10-03 Cambridge Display Technology Limited Backlit displays
US8529309B2 (en) 1998-06-19 2013-09-10 Cambridge Display Technology Limited Backlit displays including organic light-emissive material
EP1046944A3 (fr) * 1999-04-13 2001-09-12 Mannesmann VDO Aktiengesellschaft Dispositif LCD auto éclairé
US6542145B1 (en) 1999-04-13 2003-04-01 Mannesmann Vdo Ag Self-illuminating LCD display device
EP1046944A2 (fr) * 1999-04-13 2000-10-25 Mannesmann VDO Aktiengesellschaft Dispositif LCD auto éclairé
US7198533B2 (en) 1999-12-22 2007-04-03 General Electric Company Method for making an OLED device
EP1111966A3 (fr) * 1999-12-22 2006-04-19 General Electric Company Dispositif d'affichage luminescent et méthode pour la fabrication
EP1111966A2 (fr) * 1999-12-22 2001-06-27 General Electric Company Dispositif d'affichage luminescent et méthode pour la fabrication
US7576496B2 (en) 1999-12-22 2009-08-18 General Electric Company AC powered OLED device
WO2004077137A1 (fr) * 2003-02-21 2004-09-10 Universal Display Corporation Afficheur transflectif ayant une oled d'eclairage en arriere-plan
US6900458B2 (en) 2003-02-21 2005-05-31 Universal Display Corporation Transflective display having an OLED backlight
EP1746456A2 (fr) 2005-07-22 2007-01-24 AEG Gesellschaft für moderne Informationssysteme mbH Dispositif d affichage à cristaux liquides
US7911439B2 (en) 2005-07-22 2011-03-22 Aeg Gesellschaft für Moderne Informationssysteme mbH Liquid crystal display device
DE202005011574U1 (de) * 2005-07-22 2006-11-23 Aeg Gesellschaft für Moderne Informationssysteme mbH Flüssigkristallanzeige
US11488545B2 (en) 2007-06-13 2022-11-01 Interdigital Madison Patent Holdings, Sas Device for displaying images comprising two modulation stages

Similar Documents

Publication Publication Date Title
KR100630475B1 (ko) 표시장치, 그의 제조방법 및 그의 구동방법
EP0784305B1 (fr) Circuit de commande d&#39;une matrice de diodes électroluminescentes organiques
US7248235B2 (en) Display, method of manufacturing the same, and method of driving the same
US8698978B2 (en) Electroluminescent displays
JP5228268B2 (ja) 有機エレクトロルミネッセンス素子及び液晶表示装置
AU725250B2 (en) Polymer light emitting diode
US20040263045A1 (en) Optoelectronic displays
WO2004077137A1 (fr) Afficheur transflectif ayant une oled d&#39;eclairage en arriere-plan
JP4711273B2 (ja) 照明付き液晶表示装置
JP2005512124A (ja) 積層型透過性エレクトロルミネセント表示素子を備えたディスプレイ装置
US6809481B2 (en) Light emitting device and electric device using the same
JPH08211832A (ja) 複合素子型表示装置
WO1997038347A1 (fr) Eclairage par transmission pour afficheur a cristaux liquides
NL1018484C2 (nl) Werkwijze voor het elektrisch adresseren van fluorescentie-afleeselementen en afleeselement.
JP2001312918A (ja) 照明装置
JPH04308687A (ja) 有機エレクトロルミネッセンス表示装置及びその駆動方法
Visser Application of polymer light-emitting materials in light-emitting diodes, backlights and displays
CN114488594B (zh) 显示设备
US20030214240A1 (en) Contrast-adjustable panels and displays via organic light-emitting devices
JP3672060B2 (ja) 反射型液晶装置
JP4608768B2 (ja) 液晶表示装置
CN115128879A (zh) 变色模组、壳体、电子设备、隐私膜和车辆
US6727660B1 (en) Organic electroluminescent devices and method for improving energy efficiency and optical stability thereof
US20040233138A1 (en) Image display panel consisting of a matrix of memory-effect electroluminescent cells
JP2000331779A (ja) 透明画像表示用ディスプレイ及び発光装置

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): GB JP US

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FI FR GB GR IE IT LU MC NL PT SE

121 Ep: the epo has been informed by wipo that ep was designated in this application
NENP Non-entry into the national phase

Ref country code: JP

Ref document number: 97535955

Format of ref document f/p: F

122 Ep: pct application non-entry in european phase