WO1989005993A1 - Dispositifs optiques a cristaux liquides presentant un gradient controle d'ordre en surface - Google Patents
Dispositifs optiques a cristaux liquides presentant un gradient controle d'ordre en surface Download PDFInfo
- Publication number
- WO1989005993A1 WO1989005993A1 PCT/FR1988/000623 FR8800623W WO8905993A1 WO 1989005993 A1 WO1989005993 A1 WO 1989005993A1 FR 8800623 W FR8800623 W FR 8800623W WO 8905993 A1 WO8905993 A1 WO 8905993A1
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- WIPO (PCT)
- Prior art keywords
- liquid crystal
- plates
- roughness
- orientation
- thickness
- Prior art date
Links
- 239000004973 liquid crystal related substance Substances 0.000 title claims abstract description 66
- 230000003287 optical effect Effects 0.000 title description 3
- 230000010287 polarization Effects 0.000 claims abstract description 13
- 239000004990 Smectic liquid crystal Substances 0.000 claims abstract description 7
- 238000001704 evaporation Methods 0.000 claims description 40
- 230000008020 evaporation Effects 0.000 claims description 40
- 239000004988 Nematic liquid crystal Substances 0.000 claims description 8
- 230000005684 electric field Effects 0.000 claims description 8
- 238000000576 coating method Methods 0.000 claims description 7
- 238000000151 deposition Methods 0.000 claims description 7
- 239000011248 coating agent Substances 0.000 claims description 6
- 238000004873 anchoring Methods 0.000 claims description 5
- 230000008021 deposition Effects 0.000 claims description 5
- 239000000126 substance Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 3
- 238000010849 ion bombardment Methods 0.000 claims description 2
- 239000000463 material Substances 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 6
- 230000002999 depolarising effect Effects 0.000 abstract description 3
- 238000011160 research Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 239000007788 liquid Substances 0.000 description 3
- FEIWNULTQYHCDN-UHFFFAOYSA-N mbba Chemical compound C1=CC(CCCC)=CC=C1N=CC1=CC=C(OC)C=C1 FEIWNULTQYHCDN-UHFFFAOYSA-N 0.000 description 3
- 230000007850 degeneration Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000012552 review Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 241000167854 Bourreria succulenta Species 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 210000004027 cell Anatomy 0.000 description 1
- 235000019693 cherries Nutrition 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 210000002858 crystal cell Anatomy 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- UREBDLICKHMUKA-CXSFZGCWSA-N dexamethasone Chemical compound C1CC2=CC(=O)C=C[C@]2(C)[C@]2(F)[C@@H]1[C@@H]1C[C@@H](C)[C@@](C(=O)CO)(O)[C@@]1(C)C[C@@H]2O UREBDLICKHMUKA-CXSFZGCWSA-N 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 238000010884 ion-beam technique Methods 0.000 description 1
- ONCZDRURRATYFI-QTCHDTBASA-N methyl (2z)-2-methoxyimino-2-[2-[[(e)-1-[3-(trifluoromethyl)phenyl]ethylideneamino]oxymethyl]phenyl]acetate Chemical compound CO\N=C(/C(=O)OC)C1=CC=CC=C1CO\N=C(/C)C1=CC=CC(C(F)(F)F)=C1 ONCZDRURRATYFI-QTCHDTBASA-N 0.000 description 1
- 238000005459 micromachining Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
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
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
-
- 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
- G02F1/1337—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers
- G02F1/133734—Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers by obliquely evaporated films, e.g. Si or SiO2 films
-
- 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
- G02F1/137—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
-
- 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
- G02F1/137—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
- G02F1/1396—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell
- G02F1/1397—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent the liquid crystal being selectively controlled between a twisted state and a non-twisted state, e.g. TN-LC cell the twist being substantially higher than 90°, e.g. STN-, SBE-, OMI-LC cells
-
- 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
- G02F1/137—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering
- G02F1/139—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent
- G02F1/141—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 characterised by the electro-optical or magneto-optical effect, e.g. field-induced phase transition, orientation effect, guest-host interaction or dynamic scattering based on orientation effects in which the liquid crystal remains transparent using ferroelectric liquid crystals
Definitions
- the present invention relates to optical devices using liquid crystals. 5.
- the present invention was made in the Laboratory of
- the present * invention now aims to propose new means for defining, simply, reliably and economically, an oblique inclination of the liquid crystal molecules relative to a plate of the device.
- the present invention which is based on numerous theoretical studies and experimental observations, proposes for this purpose to define on a plate " of the device, a roughness of the order of molecular magnitude of the liquid crystal considered.
- the roughness thus defined on the plate of the device will be of the order of magnitude from 20 to 40 A.
- the inventors have determined that such roughness results in an order parameter gradient which induces an ordoelectric polarization, associated with a depolarizing field which tends to force the molecules of the crystal in an oblique orientation relative to the plate. More precisely still, by extending their research, the inventors have determined that, by defining a preferential direction of roughness, for example by depositing on the plate a rough coating by evaporation in a determined direction, it was possible to obtain both. controlled oblique orientation and azimuthal orientation of the liquid crystal, relative to the plates.
- the oblique orientation and the azimuthal orientation of the liquid crystal evolve continuously, in an obi plane relative to the plates as a function of the thickness of the roughness and of its preferential direction, that is to say in the case of an evaporation as a function of the direction of incidence.
- a bistable display with very low energy consumption can be obtained using a device comprising two parallel transparent plates, and a material comprising liquid crystal molecules placed between the two plates, at least one plates having on its surface adjacent to the liquid crystal a roughness of the order of molecular magnitude of the liquid crystal, the thickness and the orientation of the roughness being adapted to define two possible azimuthal orientations of the molecules of the liquid crystal, symmetrical with respect to to the preferred direction of roughness and of the order of 45 ° relative to this direction, and means making it possible to apply an electric field external to the device to cause the controlled tilting of the molecules from one azimuth orientation to the other.
- Document US-A-4 601 544 relates to a liquid crystal device having a bistable volume effect.
- Document FR-A-2 308 675 relates to micromachining, by means of an ion beam, of a coating deposited on the substrate of a liquid crystal cell.
- FIGS. 1 to 4 show, for four experiments, the azimuthal orientation Y and the oblique bearing ⁇ of the liquid crystal as a function of the angle of evaporation and the thickness of a deposit made on a plate,
- FIGS. 7, 8 and 9A, 9B schematically illustrate three applications of the invention , to nematic liquid crystal devices, and
- FIG. 10 shows curves illustrating the evolution of the oblique or ⁇ tion of a smectic liquid crystal, on each of the two faces of the device, depending on a thickness of SiO deposited.
- the present invention is based on the following theoretical analysis.
- Nematic liquid crystals can be considered as liquids of oriented electric quadrupoles for which one can write: relationship in which:
- - S represents the order parameter of the liquid crystal (S is between O and 1)
- - n is the unit vector representing the orientation of the molecules.
- the inventors proposed the idea of controlling the order parameter S, on the surface of a liquid crystal device, by depositing on a plate of the device small grains whose size is of the order of magnitude of the molecular size of the liquid crystal considered, that is to say of l '' from 20 to 40 A.
- the inventors have controlled the orientation of the liquid crystal for different pairs of evaporation angle and thickness of the deposited grains.
- the inventors have found that achieving a rough surface state by evaporation in a determined direction makes it possible to obtain not only an oblique orientation of the liquid crystal molecules relative to the plates, but also an azimuthal orientation which is controlled and variable with respect to to the direction of evaporation.
- the first results obtained are recorded in Figures 1 to 4 and 6 attached. These results are illustrated with reference to the geometric model represented in FIG. 5.
- This geometric model includes a coordinate system with three axes x, y and z, orthogonal to each other.
- the axes x, y extend parallel to the plate P considered.
- the z axis extends perpendicular to this plate P, in the direction of the volume of the liquid crystal.
- the direction of evaporation arbitrarily coincides with the plane defined by the x and z axes.
- the incidence of the direction of evaporation, which corresponds to the inclination between the direction of evaporation and the z axis is defined by the angle.
- the oblique orientation of the liquid crystal which corresponds to the inclination between the z axis and the longitudinal axis of the liquid crystal molecules is illustrated by the angle ⁇ in FIG. 5.
- the complement of this angle ⁇ is referenced ⁇ .
- the azimuthal orientation of the liquid crystal which corresponds to the inclination between the x axis and the projection on the xy plane of the longitudinal axis of the molecules is illustrated by the angle referenced ⁇ in FIG. 5.
- the evaporation angle c a gradual azimuthal rotation of the molecules in an oblique plane with respect to the plate P.
- the liquid crystal then passes from a domain for which the azimuthal orientation ⁇ equals 90 ° to an azimuthal domain for which can reach 0 °, that is to say a domain for which the molecules are oriented substantially parallel to the xz plane containing the direction of evaporation.
- azimuthal is accompanied by an increase in molecules; when T gradually goes from 90 ° to 0 °, ⁇ goes from 0 to about 20-30 °.
- the hatched range in FIG. 1 corresponds to the range of values of the evaporation angle c. and of the thickness of evaporation for which the azimuthal orientation varies progressively between 90 ° and 0 ° and the oblique orientation ⁇ varies progressively between 0 and approximately 20-30 °.
- FIG. 2 relates to tests carried out under the same operating conditions, that is to say deposition by evaporation of SiO on ordinary glass, for different values of evaporation angle and thickness of deposition, but with the difference of Figure 1, using liquid crystal 5 CB instead of MBBA.
- Figures 3 and 4 similarly represent the value of the azimuthal orientation as a function of the angle of evaporation o (and the thickness of deposition of SiO, on an ITO plate, respectively for liquid crystal MBBA d ' on the one hand, and 5CB on the other.
- Figures 2, 3 and 4 like Figure 1 above, reveal a range (hatched in the figures) of pairs of values, evaporation angle ⁇ (/ thickness of deposit, for which the orientation azimuthal ⁇ ? gradually goes from 90 ° to 0 °.
- FIG. 6 represents the simultaneous evolution of the azimuthal orientation T and of the oblique orientation ⁇ as a function of the thickness of a deposit of SiO evaporated on an ITO plate with an incidence p. 74 °, using a 5CB liquid crystal.
- the azimuthal orientation ⁇ passes progressively from 90 ° to 0 ° for a thickness of deposit substantially between 30 and 40 A.
- the oblique orientation ⁇ gradually rises from 0 to 20 ° for an evaporation thickness ranging from 30 to 40 A.
- the tests carried out by the inventors have made it possible to observe that the bare substrate, before evaporation, promotes a planar orientation, that is to say parallel to the surface, but degenerate.
- the average evaporated amount (of SiO) reaches 5 A, the azimuthal degeneration is lifted, but the anchoring remains planar.
- the nematic which turns in a oblique plane from its initial planar position, perpendicular to the direction of evaporation, to an oblique position towards the direction of evaporation.
- achieving a rough state on the plates capable of generating an order gradient, and from there thanks to the induced ordoelectric polarization, to request a raising of the liquid crystal in an oblique orientation orientation relative to the plates, can be operated by means other than evaporation, such as for example, by chemical attack, spraying, or even ion bombardment.
- the inventors have moreover determined that the molecules of the liquid crystal are capable of taking two symmetrical azimuthal orientations with respect to the plane xz containing the direction of evaporation.
- FIG. 8 We have thus schematically illustrated in FIG. 8 two azimuthal orientations symmetrical with respect to the plane xz defined by the direction of evaporation.
- the evaporation angle ⁇ and thickness evaporation on a plate so that the azimuthal orientation with respect to the xz plane is in the range of 45 ° T, it is easy, by applying an external electric field provoke the controlled tilting of the molecules from an azimuthal orientation to the other on said plate.
- both electrodes or plates have a state of
- a planar and parallel anchoring is defined on the two plates of the device, as illustrated in FIG. 9A.
- the angle of evaporation ⁇ (and the thickness of evaporation of a deposit are checked to place the liquid crystal in the vicinity of the hatched transition range in FIGS. 1 to 4.
- the liquid crystal is thus placed in the vicinity of an instability threshold, that is to say in the vicinity of an azimuthal tilting threshold.
- This arrangement facilitates the tilting of the liquid crystal towards a helical formation, by application of an external electric field, as is known per se and as illustrated diagrammatically in FIG. 9B
- Ferroelectric smectic C displays when they have a degenerate surface anchoring, theoretically allow two positions of symmetrical molecules with respect to the smectic layers. In one of these positions, the electric dipole of the molecules is oriented towards the electrode, in the other position, it is oriented towards the volume, by an external applied field. In theory, these two positions should be equivalent and allow the realization of bistable displays.
- the present invention makes it possible to cancel the chemical polarization by virtue of an ordoelectric polarization induced by the creation of a gradient of nematic order, in the smectic phase, of suitable sign and amplitude.
- FIG. 10 illustrates the orientation 0, - of the liquid crystal thus obtained on the lower and upper device plates for different thickness values of a deposit of SiO operated by evaporation at an incidence ⁇ of 81 ° on ITO plates separated by 3 ⁇ m, respectively for temperatures of 55 ° C and 48.0 ° C.
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- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Chemical & Material Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Mathematical Physics (AREA)
- Liquid Crystal (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR87/17660 | 1987-12-17 | ||
FR8717660A FR2624985B1 (fr) | 1987-12-17 | 1987-12-17 | Dispositifs optiques a cristaux liquides presentant un gradient controle d'ordre en surface |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1989005993A1 true WO1989005993A1 (fr) | 1989-06-29 |
Family
ID=9357996
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/FR1988/000623 WO1989005993A1 (fr) | 1987-12-17 | 1988-12-16 | Dispositifs optiques a cristaux liquides presentant un gradient controle d'ordre en surface |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0393128A1 (fr) |
JP (1) | JPH03502969A (fr) |
FR (1) | FR2624985B1 (fr) |
WO (1) | WO1989005993A1 (fr) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2657699A1 (fr) * | 1990-01-30 | 1991-08-02 | Centre Nat Rech Scient | Dispositif optique bistable a cristaux liquides et commande electrochirale. |
WO1991011747A1 (fr) * | 1990-01-30 | 1991-08-08 | Centre National De La Recherche Scientifique (Cnrs) | Dispositif optique bistable a cristaux liquides et commande electrochirale |
FR2663770A1 (fr) * | 1990-06-22 | 1991-12-27 | Centre Nat Rech Scient | Afficheur a cristal liquide nematique, a bistabilite de surface, commande par effet flexoelectrique. |
WO1992000546A3 (fr) * | 1990-06-22 | 1992-02-06 | Centre Nat Rech Scient | Afficheur a cristal liquide nematique, a bistabilite de surface, commande par effet flexoelectrique |
WO1995022077A1 (fr) * | 1994-02-09 | 1995-08-17 | The Secretary Of State For Defence | Dispositifs bistables a cristaux liquides nematiques |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2308675A1 (fr) * | 1975-04-21 | 1976-11-19 | Hughes Aircraft Co | Procede de realisation d'une cellule a cristaux liquides |
US4601544A (en) * | 1982-10-15 | 1986-07-22 | At&T Bell Laboratories | Nematic liquid crystal storage display device |
-
1987
- 1987-12-17 FR FR8717660A patent/FR2624985B1/fr not_active Expired - Lifetime
-
1988
- 1988-12-16 EP EP19890900833 patent/EP0393128A1/fr not_active Ceased
- 1988-12-16 JP JP1500763A patent/JPH03502969A/ja active Pending
- 1988-12-16 WO PCT/FR1988/000623 patent/WO1989005993A1/fr not_active Application Discontinuation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2308675A1 (fr) * | 1975-04-21 | 1976-11-19 | Hughes Aircraft Co | Procede de realisation d'une cellule a cristaux liquides |
US4601544A (en) * | 1982-10-15 | 1986-07-22 | At&T Bell Laboratories | Nematic liquid crystal storage display device |
Non-Patent Citations (3)
Title |
---|
Conference Record of 1978 Biennial Display Research Conference, 24-26 octobre 1978 Cherry Hill, N.J.(New York, US) R. Chabicovsky et al.: "A matrix addressed liquid crystal color display, pages 56-58 * |
Japanese Journal of Applied Physics, vol. 19, no, mars 1980 (Tokyo, JP) K. Hiroshima et al.: "Influence of Si0 film thickness on liquid crystal orientation", pages 567-568 * |
Proceedings of the Society for Information Display (SID), vol. 25, no. 4, 1984 (New York, US) K. Hiroshima et al.: "Controlled low-tilt-angle liquid-crystal orientation on "omniazimuthally" evaporated Si0 films at 60° incidence", pages 287-292 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2657699A1 (fr) * | 1990-01-30 | 1991-08-02 | Centre Nat Rech Scient | Dispositif optique bistable a cristaux liquides et commande electrochirale. |
WO1991011747A1 (fr) * | 1990-01-30 | 1991-08-08 | Centre National De La Recherche Scientifique (Cnrs) | Dispositif optique bistable a cristaux liquides et commande electrochirale |
FR2663770A1 (fr) * | 1990-06-22 | 1991-12-27 | Centre Nat Rech Scient | Afficheur a cristal liquide nematique, a bistabilite de surface, commande par effet flexoelectrique. |
WO1992000546A3 (fr) * | 1990-06-22 | 1992-02-06 | Centre Nat Rech Scient | Afficheur a cristal liquide nematique, a bistabilite de surface, commande par effet flexoelectrique |
US5357358A (en) * | 1990-06-22 | 1994-10-18 | Centre National De La Recherche Scientifique (Cnrs) | Nematic liquid crystal display with surface bistability and control by flexoelectric effect |
WO1995022077A1 (fr) * | 1994-02-09 | 1995-08-17 | The Secretary Of State For Defence | Dispositifs bistables a cristaux liquides nematiques |
GB2301446A (en) * | 1994-02-09 | 1996-12-04 | Secr Defence | Bistable nematic liquid crystal devices |
US5796459A (en) * | 1994-02-09 | 1998-08-18 | The Secretary Of State For Defence In Her Britannic Majesty's Government Of The United Kingdom Of Great Britain And Northern Ireland | Bistable nematic liquid crystal device with bigrating alignment layers and twist |
Also Published As
Publication number | Publication date |
---|---|
FR2624985B1 (fr) | 1992-08-21 |
EP0393128A1 (fr) | 1990-10-24 |
JPH03502969A (ja) | 1991-07-04 |
FR2624985A1 (fr) | 1989-06-23 |
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