WO2001079924A1 - Ensemble integre afficheur a cristaux liquides et module electroluminescent - Google Patents

Ensemble integre afficheur a cristaux liquides et module electroluminescent Download PDF

Info

Publication number
WO2001079924A1
WO2001079924A1 PCT/US2001/011813 US0111813W WO0179924A1 WO 2001079924 A1 WO2001079924 A1 WO 2001079924A1 US 0111813 W US0111813 W US 0111813W WO 0179924 A1 WO0179924 A1 WO 0179924A1
Authority
WO
WIPO (PCT)
Prior art keywords
layer
lcd
module
conductive layer
conductive
Prior art date
Application number
PCT/US2001/011813
Other languages
English (en)
Inventor
Robert Stinauer
Benjamin Rush
Original Assignee
Motorola Inc., A Corporation Of The State Of Delaware
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 Motorola Inc., A Corporation Of The State Of Delaware filed Critical Motorola Inc., A Corporation Of The State Of Delaware
Priority to AU2001253369A priority Critical patent/AU2001253369A1/en
Publication of WO2001079924A1 publication Critical patent/WO2001079924A1/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 generally to display devices that use electroluminescent modules and, more particularly, to a liquid crystal display device having an integrated a liquid crystal display module and an electroluminescent backlight module.
  • LCD liquid crystal display
  • PDAs personal data assistants
  • LCDs are used in cellular telephones, personal data assistants (PDAs) , portable computers, and other applications to display information.
  • PDAs personal data assistants
  • LCDs are their relatively small size in comparison to traditional display devices, such as cathode ray tubes.
  • LCD displays can be made substantially thin, lightweight, and, thus, portable.
  • These LCD devices may include a LCD module and an electroluminescent (EL) module.
  • EL electroluminescent
  • LCD modules use a birefringent liquid crystal material which alters the polarization state of an incident light wave.
  • This liquid crystal material is housed between two linear polarizers oriented such that their respective axes of polarization are parallel to one another. With this orientation, the light wave, which enters the liquid crystal linearly polarized along one axis is rotated into an orthogonal polarization after passing through the liquid crystal. This orthogonally polarized wave will be blocked by the linear polarizer on the exit end of the liquid crystal.
  • numerous types of switching elements may be used with LCD modules, all elements sharing substantially the same purpose, i.e., establishing an electric field across a portion of the liquid crystal such that the liquid crystal material does not alter the polarization state of the incident light wave as the light wave travels through the crystal.
  • the liquid crystal housing, front polarizer, and rear polarizer apparatus is oriented to pass light through the LCD under this electric field biasing. Such a LCD module is well known in the art.
  • EL modules have an electroluminescence phosphor layer of material that will luminesce upon excitation by electron movement across and absorption within the layer.
  • EL modules comprise a planar sandwich structure, in which two conductor layers are used, one on each side of the electroluminescence layer, to establish a current forming path across the electroluminescence layer. These two conductor layers are typically thin layer films made of conductive material .
  • One conductor layer can be placed onto a base layer that serves as the bottom of the EL module.
  • the other (i.e., upper), conductor layer may be placed on the other side of the electroluminescence layer except that the upper conductor layer must be substantially optically transparent so that luminescence from the electroluminescence layer is transmitted to the LCD module. Therefore the upper contact is usually a thin layer of conductive material deposited onto a thin insulating film.
  • the insulating film acts as a protective upper surface of the EL module package, thus allowing the package to be handled, tested, and placed in different environments of use without damaging the conductor layers or contaminating the electroluminescence layer of the EL module.
  • the EL module generally forms an electrode-dielectric- electroluminescence layer-electrode-insulating film multilayer sandwich.
  • This multilayer sandwich i.e., EL module, is attached to the rear polarizer of the LCD module, by adhesively laminating the insulating film of the EL module to the rear polarizer of the LCD module, thus forming an entire LCD device.
  • FIG. 1 is an isometric view of the integrated LCD module and EL module of an embodiment of the present invention.
  • FIG. 2 is a top plan view of a cellular telephone in which the integrated LCD module and EL module of FIG. 1 is used.
  • FIG. 3 is a top plan view of a PDA in which the integrated LCD module and EL module of FIG. 1 is used.
  • FIG. 4 is an isometric view of an alternative embodiment of the integrated LCD module and EL module.
  • FIG. 5 is an isometric view of the bottom surface of an integrated rear polarizer in accordance with an aspect of the present invention.
  • FIG. 6 is a plan view of a bottom insulating layer of the embodiment of FIG. 4. Detailed Description of the Preferred Embodiments
  • a LCD and integrated EL module As exemplified in the present description of a preferred embodiment, a LCD and integrated EL module
  • the integrated module 10 (hereinafter referenced as "the integrated module 10") is shown preassembled in a perspective view in Fig. 1.
  • the integrated module offers improvements over the disadvantages discussed above, in that it requires less layers than the state of the art and reduces the vibrational noise associated therewith.
  • the integrated module may be used in lieu of the state of the art LCD and EL modules in numerous applications, including cellular telephones 12, as shown in Fig. 2, and PDAs 14, as shown in Fig. 3. It will be readily appreciated by persons of ordinary skill in the art that the preferred embodiments may be employed in other applications as well.
  • the integrated module comprises an LCD module 16 integrated with an EL module 18.
  • the modules 16,18 are individually referenced for ease of comprehension and together form the integrated module 10.
  • the LCD module 16 comprises a front polarizer 20 and a liquid crystal housing 22 with two LCD glass panels 24, 26 all of which are rectangular in shape in a planar view.
  • each glass panel 24, 26 can have an indentation so that when the two glass panels 24, 26 are brought into contact the indentations define a space into which a liquid crystal material may be hermetically sealed.
  • the rear polarizer traditionally found in LCD modules has been replaced by an integrated rear polarizer 30 that is shared by both the LCD module 16 and the EL module 18.
  • the front polarizer 20 and the integrated rear polarizer 30 are linear polarizers with their respective axes of polarization oriented in parallel.
  • the front polarizer 20 is sized to cover the entire upper surface of the liquid crystal housing 22, or at least that functional area of the housing 22 that will be visible for display to and/or inking by the user.
  • the integrated rear polarizer 30 can cover the entire lower surface of the liquid crystal housing or its functional area.
  • biasing means may be used to establish electric fields across the liquid crystal housing 22, including a thin optically translucent indium tin oxide (ITO) contact layer placed between the upper surface of the liquid crystal housing 22 and the front polarizer 20, as well as another thin ITO contact layer placed between the lower surface of the liquid crystal housing 22 and the rear polarizer 30.
  • ITO layers absorb approximately 10% of the radiation incident upon them.
  • the integrated module 10 of FIG. 1 also comprises the EL module 18 which has numerous layers, including an electroluminescence layer 44.
  • the electroluminescence layer 44 is preferably a phosphor layer that converts electron energy, generated by a current path across the phosphor layer, into radiant energy, i.e., visible luminescence for backlighting the LCD module.
  • a phosphor layer that converts electron energy, generated by a current path across the phosphor layer, into radiant energy, i.e., visible luminescence for backlighting the LCD module.
  • other suitable electroluminescence layers may be used in the present invention.
  • the EL module 18 is shown in use in the integrated module 10, the EL module 18 with integrated rear polarizer 30 may exist separately from the integrated application, and still be within the scope of the present invention.
  • the EL module 18 includes (from bottom to top) a bottom insulating layer 48 with a rear busbar 50 and lead 52 attached thereto, a dielectric layer 54 upon which the electroluminescence layer 44 is deposited, and the integrated rear polarizer 30, each of which are rectangular in shape from a plan view and have a surface area substantially the same as the liquid crystal housing 22 or at least the functional area thereof .
  • the bottom insulating layer 48 is disposed to electrically isolate the EL module 18 from its environment of use, such as circuitry within the cellular telephone 12 or the PDA 14.
  • the bottom insulating layer is made of a polyester film of approximately 2 mil thickness to provide necessary isolation and to avoid detrimental capacitive effects. Nevertheless, one of ordinary skill in the art will recognize that other insulating materials may be used.
  • the rear busbar 50 and the lead 52 are disposed on the bottom insulating layer 48.
  • the rear busbar 50 forms one electrode current path across the electroluminescence layer 44.
  • a rear conductive layer 56 is used.
  • the rear conductive layer 56 is a carbon or silver conductive ink deposited, i.e., screened, onto the entire surface of the bottom insulating layer 48.
  • the carbon or silver ink can be screened onto two portions of the bottom insulating layer 48.
  • inks impregnated with other conductive materials such as copper, may also be used, however carbon and silver impregnated inks are preferred for their reduced resistance.
  • the rear conductive layer 56 can be used to adhesively bond the rear busbar 50 to the bottom insulating layer 54.
  • the rear busbar 50 can be separately bonded to the bottom insulating layer 48.
  • other types of rear conductive layers such as thin metallic conductive layers adhesively bonded to the bottom insulating layer 48, may be used and, as such, are considered with the scope of the present invention.
  • the lead 52 of the rear busbar 50 is connected to an AC current source 66.
  • a front busbar 60 with lead 62 is connected to a front conductive layer 64 (FIG. 5) which is formed on the bottom surface of the integrated rear polarizer 30, according to the present invention.
  • the front conductive layer 64 should be optically transparent to allow light from the EL module 18 to backlight the LCD module 16, and, thus, a layer containing ITO is used as the front conductive layer 64.
  • the ITO layer is formed onto the bottom of the integrated rear polarizer 30 by sputtering.
  • a view of the bottom surface of the integrated rear polarizer 30 with a sputtered ITO layer thereon is shown in FIG. 5.
  • the integrated rear polarizer 30 is formed of a polyester film through known means.
  • the integrated rear polarizer 30 can be approximately 7 mils thick, for example, and because the rear polarizer 30 is used by both the LCD module 16 and the EL module 18 it functions both as an insulating film upon which the front conductive layer 64 of the EL module 18 can be deposited and as a rear polarizer for the LCD module 16. Furthermore, because the front conductive layer 64 is deposited onto the bottom of the integrated rear polarizer 30, the integrated rear polarizer 30 also electrically isolates the front conductive layer 64 from the ITO layer disposed on the bottom of the liquid crystal housing 22, discussed generally above.
  • Conductive layers other than an ITO layer and means of connecting these conductive layers to a rear polarizer other than sputtering may be used.
  • a thin patterned metallic layer may be adhesively bonded to the rear polarizer.
  • This integrated rear polarizer 30 with sputtered front conductive layer 64 is advantageous over known devices, because it reduces the layers needed to form a LCD module and EL module pair by combining into one layer the rear polarizer traditionally used in LCD modules the insulating layer traditionally used in EL modules (approximately 5 mils thick) , and the adhesive laminate layer traditionally used (approximately 2.5 mils thick) to combine the two modules.
  • this combined layer i.e., the integrated rear polarizer 30
  • reductions in overall thickness of approximately 7.5 mils, or .15 mm have been shown.
  • the two modules 16, 18 are integrated in the present invention, vibrational noise between the modules will be low.
  • the liquid crystal housing 22 acts as a stiffener for the EL module 18, thus substantially attenuating the vibrational effects that occur in known non-integrated LCD and EL module devices.
  • the front conductive layer 64 is disposed in electrical contact with the electroluminescence layer 44 by adhesively bonding or laminating the integrated rear polarizer 30 to the electroluminescence layer 44.
  • the dielectric layer 54 is disposed between the electroluminescence layer 44 and the rear conductive layer 56.
  • the dielectric layer 54 is preferably made of a barium titanate. Alternatively, the dielectric layer 54 can be located in other positions such as between the front conductive layer 64 and the electroluminescence layer 44, with the rear conductive layer 56 being electrically coupled to the electroluminescence layer 44.
  • the dielectric layer 54 serves to electrically isolate the two conductive layers 56, 64 so that they do not short one another.
  • a second integrated module 68 is shown, wherein the positioning of the layers of the EL module 18 has been slightly modified to create another EL module 69 with a first busbar 70 being located on the bottom insulating layer 48 along with a second busbar 72, both with leads 74, 76, respectively.
  • the carbon or silver ink deposited onto the bottom insulating layer 48 is not deposited over the entire area as with the previous embodiment of FIG. 1, but rather is deposited onto two isolated locations 78, 80.
  • the large first portion 80 of the upper surface of the bottom insulating layer 48 is covered with conductive material. In this case, the large portion 80 is electrically connected to the second busbar 72 and serves as a rear conductive layer 78 (FIG. 6) .
  • the narrow second portion 78 of conductive material which is electrically connected to the first busbar 70.
  • the second portion 78 is connected to the front conductive layer 64 via an electrical connection not shown.
  • This electrical connection can come in numerous forms, including an external wire or conductive layer extending along a path defined by a hole 82 in the dielectric layer 54 and electroluminescence layer 44.
  • the electrical connection through the hole 82 can be formed by a conductive material, such as a carbon or silver ink layer, which is long enough to extend through the hole 82 forming an electrical contact between the front conductive layer 64 and the second conductive portion 78, but which will not short out the electroluminescence layer 44.
  • the integrated module 10 can be assembled and placed into the cellular telephone 12 or the PDA 14.
  • the leads from the rear busbar 50 and from the front busbar 60 are connected to the AC current source 66, such as an inverter circuit driven by a battery source.
  • the AC current source 66 such as an inverter circuit driven by a battery source.
  • depressing one of a group of keys 90 on the keypad 92 of the cellular telephone 12 may activate the current source 66 causing it to supply driving current to the front and rear busbars 50, 60.
  • the front and rear busbars 50, 60 connected to the front and rear conductive layers 56, 64, respectively, a current path is created through the electroluminescence layer 44 thus exciting the electroluminescence layer 44 which in turn creates a visible luminescence.
  • a portion of the visible luminescence is partially transmitted through the front conductive layer 64 and the integrated rear polarizer 30. This partially transmitted and polarized light is thereafter incident on the liquid crystal housing 22, and thus backlights the LCD module 16. Under no electric field biasing across the liquid crystal housing 22, very little backlight from the EL module 18 is transmitted from the front polarizer 20 of the LCD module 16.
  • the electrodes on the LCD may be programmed to establish electric fields across certain electrodes to selectably transmit light from the LCD module 16. For example, in FIG. 2, the keys 90 associated -with the numbers "0", "1", and "3" have been pressed and the corresponding number 34 has been displayed on the LCD screen 32.
  • a user selects from the menu bar 40 on the LCD display 36 or uses the stylus 42 to write symbols on the PDA 14 a corresponding pixelated listing of names 38 can be displayed.
  • the operation of the integrated module 68 operates in a similar manner to that of the integrated module 10.

Landscapes

  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • Mathematical Physics (AREA)
  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Devices For Indicating Variable Information By Combining Individual Elements (AREA)
  • Liquid Crystal (AREA)

Abstract

L'invention concerne un ensemble intégré (10) constitué d'un module (16) afficheur à cristaux liquides (LCD) et d'un module (18) électroluminescent (EL). Une couche (30) de polarisation est disposée entre les deux modules, de manière à servir à la fois de polariseur pour le module LCD (16) et de couche de substrat isolant pour une couche conductrice (64) du module EL (18). L'ensemble intégré (10) selon l'invention, qui comprend le module LCD, le module EL et une couche de polarisation intégrée peut être utilisé dans les téléphones cellulaires (12) et les assistants personnels de données (14).
PCT/US2001/011813 2000-04-14 2001-04-11 Ensemble integre afficheur a cristaux liquides et module electroluminescent WO2001079924A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU2001253369A AU2001253369A1 (en) 2000-04-14 2001-04-11 Integrated lcd display and electroluminescent module

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US54996100A 2000-04-14 2000-04-14
US09/549,961 2000-04-14

Publications (1)

Publication Number Publication Date
WO2001079924A1 true WO2001079924A1 (fr) 2001-10-25

Family

ID=24195118

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2001/011813 WO2001079924A1 (fr) 2000-04-14 2001-04-11 Ensemble integre afficheur a cristaux liquides et module electroluminescent

Country Status (2)

Country Link
AU (1) AU2001253369A1 (fr)
WO (1) WO2001079924A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2004077137A1 (fr) * 2003-02-21 2004-09-10 Universal Display Corporation Afficheur transflectif ayant une oled d'eclairage en arriere-plan

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4500173A (en) * 1983-05-02 1985-02-19 Timex Corporation Electroluminescent lamp for liquid crystal display

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4500173A (en) * 1983-05-02 1985-02-19 Timex Corporation Electroluminescent lamp for liquid crystal display

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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

Also Published As

Publication number Publication date
AU2001253369A1 (en) 2001-10-30

Similar Documents

Publication Publication Date Title
US7615785B2 (en) Light emitting device
TW397964B (en) Electronic device with electroluminescent panel
TW586096B (en) Dual-screen organic electroluminescent display
WO2004029918A1 (fr) Ecran
KR20170070309A (ko) 백플레이트 및 이를 포함하는 폴더블 표시장치
JPH117259A (ja) ディスプレイ装置及び端末装置
KR20020061524A (ko) 액정표시장치
CN102169387A (zh) 输入装置及电子设备
US20040080686A1 (en) Dual-display liquid crystal display
KR100863188B1 (ko) 플라스틱 평판 디스플레이
JP4608768B2 (ja) 液晶表示装置
JP2007071948A (ja) 表示装置及び電子機器
CN110320690A (zh) 一种显示装置
WO2001079924A1 (fr) Ensemble integre afficheur a cristaux liquides et module electroluminescent
JP4202652B2 (ja) 液晶表示装置及び携帯情報端末
JP4371650B2 (ja) エレクトロルミネッセンス表示装置及びこれを用いた携帯型端末
KR20110032110A (ko) 표시 장치
JP2862900B2 (ja) Ｌｃｄ表示器
JP2000267092A (ja) 液晶装置及び電子機器
CN217739670U (zh) 一种盖板与液晶盒基板集成的显示面板及电子设备
CN212675325U (zh) 液晶显示装置
JP4044328B2 (ja) 液晶表示装置
JP3003928B2 (ja) 液晶表示装置
JPH09152605A (ja) 液晶表示装置
WO2004066067A2 (fr) Interface utilisateur stratifiee multicouche

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BY BZ CA CH CN CR CU CZ DE DK DM DZ EE ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NO NZ PL PT RO RU SD SE SG SI SK SL TJ TM TR TT TZ UA UG UZ VN YU ZA ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): GH GM KE LS MW MZ SD SL SZ TZ UG ZW AM AZ BY KG KZ MD RU TJ TM AT BE CH CY DE DK ES FI FR GB GR IE IT LU MC NL PT SE TR BF BJ CF CG CI CM GA GN GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
REG Reference to national code

Ref country code: DE

Ref legal event code: 8642

122 Ep: pct application non-entry in european phase
NENP Non-entry into the national phase

Ref country code: JP