CN100407012C - A liquid crystal device and a method for manufacturing thereof - Google Patents

Abstract

The invention relates to a liquid crystal device comprising a liquid crystal bulk layer and a surface-director alignment layer comprising side-chains arranged to interact with the bulk layer, wherein the orientation of the bulk layer molecules and the orientation of said side-chains each is directly controllable by an electric field via dielectric coupling, thus resulting in a decreased total time period (rise and decay times) needed to switch and relax the liquid crystal bulk molecules in response to an applied external field. The invention also relates to a method for manufacturing a liquid crystal device and a method of controlling a liquid crystal bulk layer.

Description

Liquid crystal device and manufacture method thereof

Technical field

Relate generally to field of liquid crystals of the present invention.More specifically, the present invention relates to liquid crystal device, it is included in that there is body of liquid crystal (bulk) layer of surface orientation device (director) in its body surface and interacts with body layer at described body surface place and the surface orientation device alignment layer of arrangement so that help obtains the preferred orientation of the surface orientation device of body layer.

The invention still further relates to the method for making liquid crystal device and the method for controlling liq-uid crystal bulk layer.

Background technology

The liquid crystal that is widely used as at present the photoelectron medium in display device is the organism with anisotropy physical property energy.The normally long rodlike molecule of liquid crystal molecule, so-called calamitic molecule, it has along the ability (orientation) of its major axis calibration on some preferred directions.Determine the mean direction of molecule and be called orientor by vector.

Yet, be noted that also there is discotic liquid-crystalline molecules so-called plate-like (discotic) molecule.

Operation of LCD is based in the demonstration that causes by extra electric field (directly coupling), liquid crystal optics feature, for example variation of the absorptance under transmittance, the different wave length, light scattering, refraction, optical activity, circular dichroism etc.

One of basic principle of operation of liquid crystal display and device is the switching that causes liquid crystal molecular orientation by the extra electric field on the dielectric anisotropy that is coupled to liquid crystal (dielectric coupling).This coupling obtains the photoelectricity of extra electric field quadratic equation and replys, and is promptly irrelevant with electric polarity.There is the many inhomogeneous LCD (LCD) of its operation based on dielectric coupling, dynamic scattering display particularly, use the display of the nematic crystal distortion of reversing calibration in the same way, Schadt-Helfrich stable twisted nematic (TN) display, switch (switching) (IPS) nematic display in STN Super TN type (STN) display, face.

For modern Application, LCD should have the feature of several important, for example high-contrast and brightness, low-power consumption, low-work voltage, short rising (switching) and delay (relaxation) time, the low visual angle correlativity of contrast, gray scale or bistable state etc.LCD should be cheaply, produce easily and operate.The LCD of none prior art is being optimized aspect all these key characters.

Nematic liquid crystalline material demonstrates the simplest liquid crystal structure, i.e. anisotropic liquid.In nematic material, liquid crystal molecule is calibrated towards specific direction in the space, but the not ordering of the center of material molecule.

In the nematic LCD of most conventional, operation based on dielectric coupling, perpendicular to liq-uid crystal bulk layer (promptly, (confining) substrate perpendicular to the restriction liq-uid crystal bulk layer) applies electric field, in the face vertical, switch (switching outside so-called) by electric field with the confining substrate surface with the body of liquid crystal molecule.These show usually slowly, and almost all have the shortcoming of the dependence of angle of not satisfied contrast.

Exist to have the another kind of LCD that switches in the face, wherein apply electric field, change at the in-plane parallel with the confining substrate surface with the body of liquid crystal molecule along liq-uid crystal bulk layer (promptly parallel) with the confining substrate.These displays demonstrate the dependence of angle of very little picture contrast, but resolution and switching time are unsatisfactory.

In above-described LCD, there is not the outfield, for example under the situation of electric field, usually pass through surface treatment confining solid substrate surface suitably, for example by on the confining substrate surface of described body of liquid crystal, applying so-called (surface orientation device) alignment layer (being also referred to as oriented layer), thereby realize the required initial calibration of liquid crystal layer.Determine initial liquid crystal alignment by solid surface/liquid crystal phase interaction.The orientation of the liquid crystal molecule adjacent with the confining surface is transferred on the liquid crystal molecule in body by elastic force, thereby applies substantially the same being calibrated on all body of liquid crystal molecules.

The orientor (hereinafter being also referred to as the surface orientation device) of the liquid crystal molecule of close confining substrate surface is confined to some directions, on the point of for example vertical with the confining substrate surface (be also referred to as and reverse in the same way or vertical direction) or parallel (being also referred to as in-plane) direction.According to the symbol of dielectric anisotropy, the direction of extra electric field and the switch mode (in the face or outside the face) of required type, select to be coupled as the type of calibration of the LCD of fundamental operation between liquid crystal dielectric anisotropy and the extra electric field.

Outside utilization has the face of body of liquid crystal of negative dielectric anisotropy, switch in the liquid crystal cells, importantly evenly the orientor (under field-free state) of aligned liquid-crystal body molecule perpendicular to substrate surface (so-called reverse in the same way calibration).

Set up the example reverse Calibration Method in the same way and comprise and use surfactant that for example lecithin or cetyl trimethyl ammonium bromide are coated with the confining substrate surface.Then, the surface of also preferred wiping coat substrates in a predetermined direction is so that the plane calibration that induce the field of liquid crystal molecule is orientated on predetermined wiping direction.In laboratory study, this method can obtain good result, but never finds industrial acceptance, this is because alignment layer slowly is dissolved in the bulk liquid crystal, therefore can not get long-time stability (J.Cognard, Mol.Cryst.Liq.Cryst.Suppl.Ser.1982,1,1).

Switch in the liquid crystal cells outside utilization has the face of body of liquid crystal of positive dielectric anisotropy, importantly evenly the orientor (under field-free state) of aligned liquid-crystal body molecule is parallel to substrate surface (so-called plane calibration).For the stable twisted nematic liquid crystal cells, it is also important that, to become orientation angles (pre-tilt angle) the aligned liquid-crystal body molecule of certain inclination with substrate.

The known method of setting up plane calibration for example is inoranic membrane CVD (Chemical Vapor Deposition) method and organic membrane wiping method.

In the inoranic membrane CVD (Chemical Vapor Deposition) method, by vapour deposition inorganics obliquely, for example monox forms inoranic membrane on substrate surface to the confining substrate, so that depend on inorganics and gasification condition, on a certain direction, pass through inoranic membrane aligned liquid-crystal molecule.Because the production cost height, so this method is not suitable for large-scale production, and in fact this method can not be used.According to organic membrane wiping method, on substrate surface, for example form the organic coating of polyvinyl alcohol (PVA), polyoxyethylene, polyamide or polyimide.Use for example cloth of cotton, nylon or polyester afterwards, with this organic coating of predetermined direction wiping, so that the liquid crystal molecule that contacts with this layer is orientated on the wiping direction.

Commercial, polyvinyl alcohol (PVA) (PVA) is seldom as alignment layer, and this is because these polymkeric substance are hydrophilic, and the absorbent polymer that can absorb moisture is the molecular orientation of impact polymer unfriendly, and therefore influences the performance of liquid crystal device.In addition, PVA can attract ion, and described ion can damage the performance of liquid crystal device equally.

In addition, polyoxyethylene can attract ion, thereby causes the liquid crystal device performance damaged.

Polyamide has low solubleness in most of common acceptable solvent.Therefore, commercial polyamide seldom uses in liquid crystal device is made.

In most of the cases, polyimide is owing to its quite favourable feature, and for example therefore chemical stability, thermal stability etc. are used as organic surface coating.

Switch in the liquid crystal cells in utilization has the face of body of liquid crystal of plus or minus dielectric anisotropy, importantly evenly the orientor of aligned liquid-crystal body molecule is parallel to substrate surface.In the case the calibration steps of Shi Yonging be similar to the face that utilizes body of liquid crystal with positive dielectric anisotropy switch outward liquid crystal cells employed those.

Switch in the liquid crystal cells in utilization has the face of body of liquid crystal of positive dielectric anisotropy, the initial field-free plane calibration of body of liquid crystal molecule is perpendicular to the direction of extra electric field.

Switch in the liquid crystal cells in utilization has the face of body of liquid crystal of negative dielectric anisotropy, the initial plane calibration of body of liquid crystal molecule is along the direction of extra electric field.

In calibration all above-described methods, on the confining substrate surface of described body of liquid crystal, applying so-called (surface-orientor) alignment layer usually near the orientor of the body of liquid crystal molecule of confining substrate.

Be noted that in prior art (for example at US2002/0006480), disclose the alignment layer of the material that in its structure, has mesogenic group group.The layer of this type is mainly used under field-free state, increases the interaction between alignment layer and (internal compensation cooperates) liq-uid crystal bulk layer, but discloses the influence that alignment layer significantly is subjected to extra electric field (be it be can not pass through electric field directly actuated).

In the prior art, by realizing the new liquid crystal molecular orientation different, there is the technology of the optical property of three kinds of different change liquid crystal in principle with initial calibration.

The most widely used technology of first kind of reorientation molecule is all to apply external electric field on the bulk liquid crystal layer.Because electric field and some liquid crystal material parameters, for example directly coupling between the electric field anisotropy, therefore, if its initial calibration is corresponding to the interaction of least energy between electric field and the body of liquid crystal, then electric field will be on new direction direct reorientation body of liquid crystal molecule.

Second of molecule kind of known method is that one or two confining alignment surface of design is as light-operated " instruction (command) face " in the reorientation liquid crystal layer.This light-operated instruction face be when accepting for example UV light time, with liquid crystal molecule that the surface contacts on can change the calibrating direction that applies by the surface.K.Ichimura is at Chemical Reviews, and many papers of summary have been described the notion of " light commanded surfaces " among the 100.p.1847 (2000).More specifically, the azobenzene monolayer deposition is on the inside base surface of the interlayer element that contains the nematic crystal layer.Azobenzene molecule becomes " cis " with its configuration from " trans " under the irradiation of UV light.Down auxiliary in triethoxysilyl, the azobenzene molecule side anchors on the substrate surface.What the cis-isomer of azobenzene part applied nematic crystal reverses calibration in the same way, and cis-isomer obtains the planar orientation of liquid crystal molecule.Therefore, cause that by the UV irradiation molecular configuration changes the variation that will cause the nematic crystal molecular alignment in the alignment layer.By with the radiation of visible light sample or simply by heating it, arrive its initial calibrating direction thereby obtain relaxation to isotropic state.

The third known method of reorientation liquid crystal molecule involves use so-called electric commanded surfaces (ECS).This principle is disclosed in the international patent application No.WO00/03288 of public publication.The ECS principle is used for major control ferroelectric liquid crystals polymeric layer.According to the ECS principle, in conventional interlayer element, on the substrate inside surface of restriction liquid crystal bulk material, deposit independently ferroelectric liquid crystals polymer foil.The ferroelectric liquid crystals polymeric layer serves as the dynamic surface alignment layer, and described dynamic surface alignment layer gives plane or the calibration on plane basically on adjacent liquid crystal bulk material.Therefore more particularly, when on the whole unit and when applying external electric field on whole surperficial alignment layer, the molecule in ferroelectric liquid crystals polymeric layer independently will switch.Switch conversely can be by being transferred in the body at the elastic force at the interface between alignment layer and the body layer independently for this a part in polymeric layer independently, thereby cause switching in the face relatively fast because of the bulk volume molecule of dynamic surface alignment layer mediation.The ECS layer should extremely thin (100-200nm) and should be preferably with bookshelf geometric configuration orientation, and promptly smectic layer is vertical with the confining substrate.In addition, in order to keep the ECS layer and to operate completely, the material of ECS layer should be soluble in liquid crystal bulk material.

In order to optimize the performance of liquid crystal device, the hope reduction is made when replying extra electric field and being switched and required total time period of relaxation body of liquid crystal molecule.Total response time is by forming rise time (liquid crystal molecule switches to an induced orientation state) and time delay (the liquid crystal molecule relaxation becomes field-free state of orientation).In the liquid crystal device of prior art, the rise time is shorter than time delay usually, and for example the rise time can be that about 1/3 and time delay of total response time can be about 2/3 of total response times.

The face of prior art is generally about 20-100ms circumscribed time delay of changing the nematic liquid crystal device, and especially for mobile image, this causes low picture quality.For the liquid crystal device with big display area with especially switch liquid crystal device outward for face, time delay, long problem was more serious.

Has the long rise time, and the liquid crystal device of total response time of therefore growing, especially for mobile image, low picture quality also is provided, for liquid crystal device with big display area, especially for switching liquid crystal device in the face, the rise time problem of length is more serious.The surface orientation device that switches liquid crystal molecule in the face causes being limited to sometimes because of substrate surface, and therefore slack-off.The rise time that the face inscribe of prior art is changed the nematic liquid crystal device is generally about 10-20ms.

The face that Fig. 1 illustrates prior art switches the principle of liquid crystal device 1 outward, and described liquid crystal device 1 is included in the liq-uid crystal bulk layer 2 that has negative dielectric anisotropy (Δ ε＜0) between the confining substrate 3.Under field-free state (E=0), by the conventional surface orientation device alignment layer (not shown) that applies on confining substrate surface 3, the body of liquid crystal molecule is by the elastic force vertical calibration.When on confining substrate surface 3, when applying external electric field (E ≠ 0) between the electrode 4 on whole liq-uid crystal bulk layer 2, liquid crystal molecule 2 switches to the planar orientation that induce the field.Yet, being positioned near confining substrate surface 3 liquid crystal molecules 2 and not only being subjected to the influence of extra electric field, and be subjected to the influence of surface orientation device alignment layer, this causes near the elastic deformation D1 of liquid crystal layer 2 substrate surface 3, as shown in Figure 1.After removing the outfield, near liquid crystal molecule 2 relaxations surface orientation device alignment layer are to its initial field-free orientation, and this is owing to solid surface/liquid crystal phase interaction causes.The relaxation of the liquid crystal molecule 2 in this zone is by the orientation of the distant body of liquid crystal molecule 2 of elastic force influence.Therefore, under extra electric field, the elastic deformation D1 that takes place in liquid crystal layer 2 disappears, and recovers initial even field-free of whole liq-uid crystal bulk layer 2 at last and reverse calibration in the same way.Yet as mentioned above, relaxation is quite slow to field-free orientation, thereby causes quite long time delay.

Face for prior art shown in Figure 2 switches liquid crystal device 1` outward, problem with same-type, wherein said device 1` is included in the liq-uid crystal bulk layer 2` that has positive dielectric anisotropy (Δ ε＞0) between the confining substrate 3` that is coated with conventional surperficial alignment layer (not shown).Under field-free state (E=0), body of liquid crystal molecule 2` demonstrates plane calibration.When on confining substrate 3`, when on whole bulk liquid crystal layer 2`, applying external electric field (E ≠ 0) between the electrode 4`, liquid crystal molecule 2` switch to the field induce vertical orientated.Fig. 2 shows the elastic deformation D2 of liquid crystal layer 2` substrate surface 3` near.

Fig. 3 illustrates the interior top view that switches liquid crystal device 1`` of face of prior art, and described liquid crystal device 1`` is included in the liq-uid crystal bulk layer 2`` that has positive dielectric anisotropy (Δ ε＞0) between the confining substrate 3`` (showing only substrate).Under field-free state (E=0), Fig. 3 a, body of liquid crystal molecule 2`` are on first direction of orientation of gained, and by being applied to the surface orientation device alignment layer (not shown) on the confining substrate surface 3``, by elastic force, display plane is calibrated.When between the electrode 4`` in placement shown in Figure 3 when bulk liquid crystal layer 2`` (promptly parallel with the confining substrate) applies external electric field (E ≠ 0), Fig. 3 b, liquid crystal molecule 2`` switches to second direction of orientation that induce the field in the electric field orientation face.Yet shown in Fig. 3 b, the orientation of liquid crystal molecule 2`` is subjected to the restriction of surface orientation device alignment layer, thereby causes the quite long rise time.

Identical reason is suitable for comprising that liq-uid crystal bulk layer has the liquid crystal device that switches in the face of negative dielectric anisotropy (Δ ε＜0).

Summary of the invention

In view of the above-described shortcoming of known liquid crystal device, general purpose of the present invention provides improved liquid crystal device, makes improving one's methods and controlling improving one's methods of liquid crystal device of liquid crystal device.The present invention is not only at display, and can be used for many other liquid crystal devices.

According to a first aspect of the invention, a kind of liquid crystal device is provided, it is included in the liq-uid crystal bulk layer that there is the surface orientation device in its body surface place, with surface orientation device alignment layer, described surface orientation device alignment layer is included in the side chain of described body surface place for interacting and to arrange with body layer, so that help to obtain the preferred orientation of the surface orientation device of body layer, wherein the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer is directly controlled by dielectric coupling by electric field separately.

In first embodiment of device of the present invention, liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.This device is by shortening time delay for example to being lower than 20ms, and for example about 4-6ms makes and can shorten total response time, and therefore especially for mobile image and big display device, provides improved picture quality.This effect is switched advantageous particularly in the liquid crystal device outside face.

In second embodiment of device of the present invention, liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of same-sign.This device is by shortening the rise time, and for example to being lower than 10ms, for example about 1-5ms makes and can shorten total response time, and therefore especially for mobile image and big display device, provides improved picture quality.This effect is switched advantageous particularly in the liquid crystal device in face.

In the 3rd embodiment of device of the present invention, surface orientation device alignment layer comprises the structure division of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.It is believed that this device by shortening rise time and time delay, makes and can shorten total response time.

According to a second aspect of the invention, the method of making liquid crystal device is provided, this method comprises the steps: to provide surface orientation device alignment layer on the inside surface of at least one substrate, and between two substrates, accompany liq-uid crystal bulk layer, there is the surface orientation device in described liq-uid crystal bulk layer at its body surface place, be included as in described body surface place and body layer with described surface orientation device alignment layer and interact and the side chain arranged, so that help to obtain the preferred orientation of the surface orientation device of body layer, wherein the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer can directly be controlled by dielectric coupling by electric field separately.

According to a third aspect of the invention we, the method of control liq-uid crystal bulk layer is provided, this method comprises the steps: by using surface orientation device alignment layer, be aligned in the liq-uid crystal bulk layer that there is the surface orientation device in its body surface place, wherein said surface orientation device alignment layer is included as at described body surface place and body layer and interacts and the side chain of arrangement, so that help to obtain the preferred orientation of the surface orientation device of body layer, wherein the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer can directly be controlled by dielectric coupling by electric field separately.

Description of drawings

The face that Fig. 1 illustrates prior art switches liquid crystal device outward, and it demonstrates the initial vertical calibration of liq-uid crystal bulk layer.

The face that Fig. 2 illustrates prior art switches liquid crystal device outward, and it demonstrates the initial plane calibration of liq-uid crystal bulk layer.

Fig. 3 illustrates the interior liquid crystal device that switches of face of prior art.

Fig. 4 illustrates of the present invention the outer embodiment of switching liquid crystal device, and it demonstrates the initial vertical calibration of liq-uid crystal bulk layer, and wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.

Fig. 5 and 6 illustrates Fig. 1 and device shown in Figure 4 difference between aspect the elastic deformation respectively.

Fig. 7 illustrates of the present invention the outer embodiment of switching liquid crystal device, and it demonstrates the initial plane calibration of liq-uid crystal bulk layer, and wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.

Fig. 8 and 9 illustrates Fig. 2 and device shown in Figure 7 difference between aspect the elastic deformation respectively.

Figure 10 illustrates the embodiment of switching liquid crystal device in of the present invention, and wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.

Figure 11 illustrates arrays of interdigitated electrodes.

Figure 12 and 13 illustrates of the present invention the outer embodiment of switching liquid crystal device, and wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of same-sign.

Figure 14 and Figure 15 show of the present invention the outer embodiment of switching liquid crystal device, and described liquid crystal device comprises that the two layers of surface orientor alignment layer of the dielectric anisotropy (Δ ε) that demonstrates contrary sign shows.

Figure 16 and 17 illustrates of the present invention the outer embodiment of switching liquid crystal device with surface orientation device alignment layer, and described liquid crystal device has the structure division of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.

Figure 18-20 demonstrates rising and the time delay that the device of embodiment 1-3 is measured respectively, and all devices demonstrate the initial vertical calibration of liq-uid crystal bulk layer.

Figure 21 demonstrates rising and the time delay that the device of embodiment 5 is measured, and described device demonstrates the initial plane calibration of liq-uid crystal bulk layer.

Should be noted that accompanying drawing does not proportionally draw.

Embodiment

What have structural anisotropy has an ordered molecular structure, and for example the dielectric anisotropy of the material of crystallization or liquid crystal structure (Δ ε) is in this material, and with respect to preferred molecular orientation, the specific inductive capacity of measuring on vertical and parallel direction is poor respectively.

When electric field is applied on the liquid crystal material that demonstrates positive dielectric anisotropy (Δ ε＞0), molecule will be calibrated its major axis along (or basically along) direction of an electric field.

When electric field is applied on the liquid crystal material that demonstrates negative dielectric anisotropy (Δ ε＜0), molecule will be calibrated its major axis perpendicular to (or being substantially perpendicular to) direction of an electric field.

Liquid crystal device of the present invention is included in the liq-uid crystal bulk layer that there is the surface orientation device in its body surface place, with surface orientation device alignment layer, described surface orientation device alignment layer is included in the side chain of described body surface place for interacting and to arrange with body layer, so that help to obtain the preferred orientation of the surface orientation device of body layer, wherein the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer is directly controlled by dielectric coupling by electric field separately.

Liquid crystal device is preferably included at least one confining substrate at described body surface place, for example two confining substrates.

Surface orientation device alignment layer preferably is applied on the described substrate inside surface of restriction liq-uid crystal bulk layer.

Liq-uid crystal bulk layer comprises the liquid crystal material that demonstrates (non-zero) dielectric anisotropy, and wherein therefore the molecular orientation of liquid crystal material molecules can directly be controlled by dielectric coupling by extra electric field.

Surface orientation device alignment layer comprises the material that demonstrates (non-zero) dielectric anisotropy and be included as the side chain of arranging with the body layer interaction, and therefore the molecular orientation of wherein said side chain can directly be controlled by dielectric coupling by extra electric field.

As used hereinly applying electric field be meant on the material of " can directly by extra electric field control ", is that the initial orientation of the molecule in this material is affected, and for example improves or changes (switching) as the result of impressed field.

The preferred nematic crystal of the liq-uid crystal bulk layer of device of the present invention.

Liq-uid crystal bulk layer can comprise having evenly or the nematic liquid crystalline material of distressed structure.Homogeneous texture can be for example the plane, reverse in the same way or incline structure.Distressed structure can be for example to reverse (being stable twisted nematic or cholesteric) or have tubaeform and/or elasticity of flexure distortion.

The nematic crystal molecule of body layer can be achirality or chiral molecules.

In the preferred embodiment of the following stated, provided the example of the suitable body of liquid crystal layer material that has the positive and negative dielectric anisotropy respectively.

The material of surface orientation device alignment layer can or have liquid crystal property or it can not have liquid crystal property.

Preferably, the material of surface orientation device alignment layer is a liquid crystal material, for example nematic or smectic crystal material, perhaps when the material of surface orientation device alignment layer contacts with liq-uid crystal bulk layer, the alternate liquid crystal property of inducing between surface orientation device alignment layer and body layer.

Preferably, (itself or induce when contact) with body layer surface orientation device alignment layer has higher invariant parameter (S) than liq-uid crystal bulk layer, so higher elastic constant (K).Higher invariant parameter causes switching faster/relaxation, therefore short response time.The invariant parameter of nematic crystal be generally about 0.5 and the invariant parameter of smectic crystal be generally about 0.8-1.0.Therefore, if use the nematic body layer, should preferably provide the smectic sequence when then surface orientation device alignment layer contacts with body layer.

The material of surface orientation device alignment layer can for example be a polymeric material, for example the polyvinyl alcohol (PVA) of chemical modification, Pioloform, polyvinyl acetal, polyimide, polysiloxane, polyacrylate, polymethacrylate, polyamide, polyester, polyurethane etc.

Can be at first by on substrate surface, applying polymer coating with reactive group, afterwards by with the reaction-ity group reaction of polymkeric substance, required side chain chemistry is connected on the described polymer coating, produce surface orientation device alignment layer, thereby required surface orientation device alignment layer is provided.

Also can be by on substrate surface, applying the polymkeric substance of modification, thus surface orientation device alignment layer produced.

Perhaps, surface orientation device alignment layer can comprise the non-polymer solid material of chemical modification, for example has the gold surface of the side chain of chemistry connection, silica surface or glass surface (containing silanol).

In the embodiment of the following stated, provided the example of the suitable surface orientor alignment layer material of the dielectric anisotropy that has positive and negative respectively.In an embodiment, one or more side chains are connected on the main polymer chain (Z).

In the application's chemical formula, use following writing a Chinese character in simplified form:

R1 and R2 are aliphatic hydrocarbon chain independently of one another, and for example alkyl preferably contains 1-20 carbon atom, the alkyl of 2-12 carbon atom for example,

R3 (expression is atom at interval) is to contain at least 2, preferred 2-20, for example 4-20, more preferably 5-20 carbon atom or heteroatomic aliphatic hydrocrbon, as alkyl, siloxane, glycol chain, perhaps its any combination (should be noted that, carbon atom or heteroatoms number can be along the random variations of main polymer chain)

R4 is an aliphatic hydrocarbon chain, and for example alkyl preferably contains 1-20 carbon atom, the alkyl of 1-5 carbon atom for example,

R5 and R6 are aliphatic hydrocrbon, siloxane, glycol chain or its any combination independently of one another, and it preferably contains 4-22,6-20 for example, and more preferably 8-18, for example 9-15 carbon atom or heteroatoms,

X and Y are H, F, Cl, CN or CF independently of one another ₃,

X ₁And Y ₁Be F or Cl independently of one another, preferred F and

Z is the part of main polymer chain (main polymer chain).

In the present invention, should be noted that at least some side chain (S of surface orientation device alignment layer material _n) be to move freely its molecular orientation (can directly control) as its dielectric coupling to the direct result on the extra electric field.What therefore, the intramolecular interaction of the physics between the remainder of described side chain and surface orientation device alignment layer material should be preferably weak.For example, can be by the surface orientation device alignment layer material a little less than the intramolecular interaction of physics between the remainder that is chosen in described side chain and this material, perhaps, for example by between the remainder of described side chain and this material, using base at interval, prevent the intramolecular interaction of this physics by steric hindrance, thereby obtain interaction than low degree.

Surface orientation device alignment layer material in device of the present invention is preferably included in defined polymkeric substance among pendent International Patent Application PCT/SE2004/000300.This base polymer comprises main polymer chain (Z), preferably polyethylene acetal and the side chain (S that is connected thereto _n), wherein main polymer chain does not have the ring structure of direct coupling and each side chain of at least some side chains to comprise by at least two phenyl that do not replace and/or replace that are selected from following coupling base coupling: the unit of carbon-carbon single bond (-), carbon-carbon double bonds (CH=CH-), the unit of carbon containing carbon triple bond (C ≡ C-), methylene ether unit (CH ₂O-), ethyleneether units (CH ₂CH ₂O-), ester units (COO-) and the azo unit (N=N-), these side chains demonstrate dipole moment permanent and/or that induce, described dipole moment provides dielectric anisotropy with orderly phase form, and by at least two interval atoms, preferably at least 5 interval atoms are connected on the main polymer chain.The preparation of this base polymer is disclosed in PCT/SE2004/000300.

" side chain " as used herein be meant from straight chain molecule, for example the atomic radical of branching on the main polymer chain.

" unsubstituted phenyl " as used herein is meant phenyl, for example-and C ₆H ₄-and-C ₆H ₅-.

" substituted-phenyl " as used herein is meant wherein one or more hydrogen atoms quilts not homoatomic or the alternative phenyl of group.

" at interval atom " as used herein is meant side chain is connected to atom on the main polymer chain.

The ring structure of coupling " directly " as used herein is meant the ring structure that condenses and with the ring structure (promptly using the ring structure of only one or more chemical bond couplings) of only singly-bound or multikey coupling.

Preferably, do not have the described main polymer chain of the ring structure of direct coupling to comprise unit according to the first kind random distribution of following formula:

S wherein ₁Represent first side chain, described first side chain comprises by two phenyl that do not replace and/or replace that are selected from following coupling base coupling at least: the unit of carbon-carbon single bond (-), carbon-carbon double bonds (CH=CH-), the unit of carbon containing carbon triple bond (C ≡ C-), methylene ether unit (CH ₂O-), ethyleneether units (CH ₂CH ₂O-), (COO-) (N=N-), this side chain demonstrates dipole moment permanent and/or that induce to ester units, and described dipole moment provides dielectric anisotropy with orderly phase form with the azo unit; At least two atoms at interval, wherein first side chain is connected on the main polymer chain by described interval atom and according to the unit of the second class random distribution of following formula:

When main polymer chain comprised the unit of random distribution of these types, polymkeric substance was a Pioloform, polyvinyl acetal.

In addition, main polymer chain can preferably also comprise the unit according to the 3rd class random distribution of following formula:

S wherein ₂Represent second side chain, described second side chain is different from S ₁, demonstrating dipole moment permanent and/or that induce, described dipole moment provides dielectric anisotropy with orderly phase form; At least two interval atoms, wherein second side chain is connected on the main polymer chain by described interval atom.Pass through S ₂The dielectric anisotropy that provides can be different from passes through S ₁The dielectric anisotropy that provides.

Preferably, the described second side chain S ₂Comprise by at least two phenyl that do not replace and/or replace that are selected from following coupling base coupling: the unit of carbon-carbon single bond (-), carbon-carbon double bonds (CH=CH-), the unit of carbon containing carbon triple bond (C ≡ C-), methylene ether unit (CH ₂O-), ethyleneether units (CH ₂CH ₂O-), ester units (COO-) and the azo unit (N=N-).

Main polymer chain also can comprise the unit according to further (the 3rd or the 4th) class random distribution of following formula:

S wherein ₃The expression side chain, described side chain is different from S ₁And S ₂, do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy be not provided.Can use required specific side chain S ₁, randomly in conjunction with required specific side chain S ₂, this class unit is incorporated in the main polymer chain, obtain polymkeric substance, described polymkeric substance demonstrates some required dielectric anisotropies with orderly phase form.Therefore, can use not demonstrate any permanent and/or dipole moment of inducing, and therefore the side chain S of any dielectric anisotropy is not provided ₃Thereby, reduce the dielectric anisotropy of the polymkeric substance of orderly phase form.

Device of the present invention is preferred or face is outer switches or the interior liquid crystal device that switches of face.

1. the contrary sign of dielectric anisotropy

In first group of embodiment of device of the present invention, liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.The preferred face of described device switches liquid crystal device outward.

A) face switches liquid crystal device outward

According to first group of embodiment of the present invention, outside having the face of initial plane calibration, switch in the liquid crystal device, (in the liq-uid crystal bulk layer) described surface orientation device is at the suprabasil orthogonal projection of confining (the surface orientation device that is called as projection), in the geometric surface parallel, has described preferred orientation (being called preferred field-free planar orientation) with described substrate, can directly control with the molecular orientation of described body layer by applying electric field, so as the described preferred planar oriented surface of the surface orientation device of projection switch to outward the field induce vertical orientated.

According to first group of embodiment of the present invention, outside having the face of initial vertical calibration in the switch spare, the orthogonal projection (the surface orientation device that be called as projection) of (in the liq-uid crystal bulk layer) described surface orientation device on the geometrical plane vertical with described substrate, has described preferred orientation (being called preferred field-free vertical orientated), can directly control with the molecular orientation of described body layer, so that the described preferred vertical orientation face of the surface orientation device of projection switches to the planar orientation that induce the field outward by applying electric field.

In the switching device outside of the present invention, apply electric field (promptly perpendicular to liq-uid crystal bulk layer) perpendicular to the confining substrate.

Fig. 4 shows according to an of the present invention outer part of switching the embodiment of liquid crystal device 5, and wherein surface orientation device alignment layer 6 is applied on the inside surface of the substrate 7 that limits liq-uid crystal bulk layer 8.Body of liquid crystal 8 demonstrates negative dielectric anisotropy (Δ ε＜0) and surface orientation device alignment layer 6 demonstrates positive dielectric anisotropy (Δ ε＞0).

In this embodiment, the molecule of surface orientation device alignment layer 6 (being side chain) has initial vertical orientated with respect to confining substrate surface 7, thereby causes under field-free state (E=0), the body of liquid crystal molecule 8 of vertical or perpendicular calibration.Also preferred folk prescription is to wipe surfaces orientor alignment layer 6, the preferred orientation of the plane calibration of inducing with the field that obtains body of liquid crystal molecule 8.

Comprise two layers of surface orientor alignment layer 6 (two sides embodiment) even should be noted that device shown in Figure 45, device of the present invention for example can or comprise only layer of surface orientor alignment layer (single face embodiment).

When applying external electric field (E ≠ 0) perpendicular to liq-uid crystal bulk layer 8 between the electrode in confining substrate 79, the body of liquid crystal molecule 8 of vertical or perpendicular calibration is because its negative dielectric anisotropy causes face to switch to the planar orientation that induce the field outward.Yet the molecule of surface orientation device alignment layer 6 (being side chain) is because its positive dielectric anisotropy causes keeping its initial vertical orientation, thisly initial vertical orientatedly be improved and stablize by the electric field that adds.In other words, when applying electric field on layer 6, the molecule of surface orientation device alignment layer 6 (being side chain) will can not switch, thereby cause near the strong elasticity distortion D3 of liquid crystal layer 8 substrate surface 7.When removing outfield (E=0), the vertical orientated molecule of surface orientation device alignment layer 6 (being side chain) will promote to get back to from the field quick relaxation of planar orientation of inducing of body of liquid crystal molecule 8 that it is field-free vertical orientated.Therefore, elastic deformation D3 shown in Figure 4 is better than elastic deformation D1 shown in Figure 1, and therefore, in the case, relaxation will be faster than situation shown in Figure 1 to field-free orientation.Fig. 5 and 6 also illustrates the comparison of D1 and D3 respectively.

Liq-uid crystal bulk layer 8 can have negative dielectric anisotropy in-6 to-1 scope and surface orientation device alignment layer 6 can have positive dielectric anisotropy in 1 to 30 scope.

Formula I-X is the example that is suitable for providing the surface orientation device alignment layer material of initial field-free vertical calibration in above-mentioned embodiment (switching liquid crystal device outside the face).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain demonstrates dipole moment permanent and/or that induce, and described dipole moment provides positive dielectric anisotropy with orderly phase form.

Formula I formula II

Formula III formula IV

Formula V

Formula VI

Formula VII

Formula VIII

Formula IX formula X

In above-described embodiment, be suitable for representing with formula XI-XIII as the instantiation of this base polymer of surface orientation device alignment layer material.

Formula XI formula XII

Formula XIII

Formula XIV-XVI is the further example that is suitable for providing the surface orientation device alignment layer material of initial field-free vertical calibration in above-mentioned embodiment (switching liquid crystal device outside the face).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁) and the side chain (S of chemical bonding ₃), described side chain (S ₁) demonstrating dipole moment permanent and/or that induce, described dipole moment provides positive dielectric anisotropy with orderly phase form, described side chain (S ₃) do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy is not provided.

Formula XIV formula XV

Formula XVI

In above-described embodiment, be suitable for representing with formula XVII-XXVIII as the instantiation of this base polymer of surface orientation device alignment layer material.

Formula XVII formula XVIII

Formula XIX formula XX

Formula XXI formula XXII

Wherein R4 is CH ₃(m+n)/o in the 25/50-43/14 scope, preferably be higher than 40/20, for example 42/16 and m/n in the 9/1-1/9 scope, preferred 3/1-1/3, for example 2/1 and

Formula XXIII formula XXIV

Formula XXV formula XXVI

Formula XXVII formula XXVIII

Formula XXIX representative is suitable for providing the further example of the surface orientation device alignment layer material of initial field-free vertical calibration in above-mentioned embodiment (switching liquid crystal device outside the face).These polymkeric substance comprise the side chain (S that two classes are different ₁And S ₂) and side chain (S ₃), described side chain (S ₁And S ₂) demonstrating dipole moment permanent and/or that induce, described dipole moment provides positive dielectric anisotropy with orderly phase form, described side chain (S ₃) do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy is not provided.

Formula XXIX

In above-described embodiment, be suitable for representing with formula XXX-XXXII as the instantiation of this base polymer of surface orientation device alignment layer material.

Formula XXX formula XXXI

Wherein R4 is CH ₃, R5 is CH ₃(m+n)/o in the 25/50-43/14 scope, preferably be higher than 40/20, for example 42/16 and m/n in the 9/1-1/9 scope, preferred 3/1-1/3, for example 2/1 and

Formula XXXII

Skilled those skilled in the art is well known that, do not use polymkeric substance, the side chain of formula I-XXXII can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

It should be noted that, outside of the present invention in the embodiment of switch spare, described device comprises the two layers of surface orientor alignment layer on the substrate surface that is applied to the restriction liq-uid crystal bulk layer, wherein surface orientation device alignment layer demonstrates positive dielectric anisotropy, demonstrate negative dielectric anisotropy with liq-uid crystal bulk layer, the dipole moment of the side chain of each surface orientation device alignment layer can have or identical direction or opposite direction.

This device with the two-layer independently alignment layer that demonstrates identical dipole moment direction can exemplify the device that has according to the two-layer independently alignment layer of the material of formula XIX (or formula XVIII).

This device with the two-layer independently alignment layer that demonstrates opposite dipole moment direction can exemplify to have according to one deck alignment layer of the material of formula XIX (or formula XVIII) with according to the device of one deck alignment layer of the material of formula XVII.

The example of the body of liquid crystal layer material that has negative dielectric anisotropy and be suitable for using in the above-described embodiment is, the potpourri of MLC6608 (Δ ε=-4.2) and MBBA (Δ ε=-0.8), the potpourri of MLC6884 (Δ ε=-5.0) and MBBA (Δ ε=-0.8), and the potpourri of MDA98-3099 (Δ ε=-6) and MBBA (Δ ε=-0.8), all these are the nematic liquid crystalline material by the Merck supply.

Fig. 7 shows an of the present invention outer part of switching another embodiment of liquid crystal device 10, and wherein surface orientation device alignment layer 11 is applied on the inside surface of the substrate 12 that limits liq-uid crystal bulk layer 13.Body of liquid crystal 13 demonstrates positive dielectric anisotropy (Δ ε＞0) and surface orientation device alignment layer 11 demonstrates negative dielectric anisotropy (Δ ε＜0).

In this embodiment, the molecule of surface orientation device alignment layer 11 (being side chain) has initial planar orientation with respect to confining substrate surface 12, thereby cause under field-free state (E=0) plane or the body of liquid crystal molecule 13 of plane calibration basically.Also preferred folk prescription is to wipe surfaces orientor alignment layer 11, with the preferred orientation (under field-free state) of the plane calibration that obtains the body of liquid crystal molecule.

Comprise two layers of surface orientor alignment layer 11 (two sides embodiment) even should be noted that device shown in Figure 7 10, device of the present invention for example alternately comprises only layer of surface orientor alignment layer (single face embodiment).

When applying external electric field (E ≠ 0) perpendicular to liq-uid crystal bulk layer 13 between the electrode in confining substrate 12 14, the plane or basically the body of liquid crystal molecule 13 of plane calibration because its positive dielectric anisotropy causes face to switch to vertical orientated that the field induces outward.Yet the molecule of surface orientation device alignment layer 11 (being side chain) is because its negative dielectric anisotropy causes keeping its initial uniform in-plane orientation, and this initial planar orientation is improved by extra electric field and stablizes.In other words, when applying electric field on layer 11, the molecule of surface orientation device alignment layer 11 (being side chain) will can not switch.When removing outfield (E=0), the molecule of the planar orientation of surface orientation device alignment layer 11 (being side chain) will promote to get back to its initial field-free planar orientation from the vertical orientated quick relaxation that induce the field of body of liquid crystal molecule 13.Therefore, elastic deformation D4 shown in Figure 7 is better than elastic deformation D2 shown in Figure 2, and Fig. 8 and Fig. 9 also illustrate the comparison of D2 and D4 respectively.

Liq-uid crystal bulk layer 13 can have positive dielectric anisotropy in 1 to 30 scope and surperficial alignment layer 11 can have negative dielectric anisotropy in-6 to-1 scope.

Formula XXXIII-XLIII is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (liquid crystal device outside the face).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain demonstrates dipole moment permanent and/or that induce, and described dipole moment provides negative dielectric anisotropy with orderly phase form.

Formula XXXIII formula XXXIV

Formula XXXV formula XXXVI

Formula XXXVII formula XXXVIII

Formula IXL formula XL

Formula XLI

Formula XLII formula XLIII

The instantiation that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (switching liquid crystal device outside the face) is the polymkeric substance according to formula XLIV.This polymkeric substance comprises side chain (S ₁) and side chain (S ₃), described side chain (S ₁) demonstrating dipole moment permanent and/or that induce, described dipole moment provides negative dielectric anisotropy with orderly phase form, described side chain (S ₃) do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy is not provided.

Formula XLIV

Wherein (m+n)/o preferably is higher than 40/20 in the 25/50-43/14 scope, for example 43/18 and m/n in the 9/1-1/9 scope, preferred 3/1-1/3, for example 1/1.

In above-described embodiment, be suitable for representing with formula XLV as another instantiation of this base polymer of surface orientation device alignment layer material.

Formula XLV

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula XXXIII-XLV can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

The example of the body of liquid crystal layer material that has positive dielectric anisotropy and be suitable for using in the above-described embodiment is, E44 (Δ ε=+ 16.8), E9 (Δ ε=+ 16.5) and E70A (Δ ε=+ 10.8), all these are the nematic liquid crystalline material by the BDH/Merck supply.

Embodiment shown in Fig. 4 and 7 comprises that face switches liquid crystal device outward, and wherein each device comprises the liq-uid crystal bulk layer and the surface orientation device alignment layer of the dielectric anisotropy that demonstrates contrary sign.It should be noted that, demonstrating the surface orientation device alignment layer of dielectric anisotropy of contrary sign and the combination of liq-uid crystal bulk layer also is available and favourable for switching liquid crystal device in (the following stated) face, although the influence of the time delay of reduction is more outstanding for face switches liquid crystal device outward.Therefore, wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate contrary sign dielectric anisotropy device of the present invention preferably face switch liquid crystal device outward.

B) switch liquid crystal device in the face

According to first group of embodiment of the present invention, in face in the switching device with initial first plane calibration, (in the liq-uid crystal bulk layer) described surface orientation device is at described suprabasil orthogonal projection (the surface orientation device that is called as projection), in the geometric surface parallel, has described preferred orientation (being called preferred field-free planar orientation) with described substrate, can directly control with the molecular orientation of described body layer, so that switch to second planar orientation that induce the field in the described preferred planar oriented surface of the surface orientation device of projection by applying electric field.

In of the present invention interior switching device, apply electric field with the direction parallel direction of liq-uid crystal bulk layer (promptly along) with the confining substrate.

Figure 10 shows according to a part of switching the embodiment of liquid crystal device 15 in of the present invention, and wherein surface orientation device alignment layer 16 is applied on the inside surface of substrate 17 (only showing a substrate) of restriction liq-uid crystal bulk layer 18.Body of liquid crystal 18 demonstrates positive dielectric anisotropy (Δ ε＞0) and surface orientation device alignment layer 16 demonstrates negative dielectric anisotropy (Δ ε＜0).

In this embodiment, the molecule of surface orientation device alignment layer 16 (being side chain) has initial planar orientation with respect to confining substrate surface 17, thereby cause under the field-free state of Figure 10 (E=0) plane or the body of liquid crystal molecule 18 of plane calibration basically.Preferred folk prescription is to wipe surfaces orientor alignment layer 16, to obtain preferred field-free first planar orientations.

Should be noted that device shown in Figure 10 15 can or comprise two layers of surface orientor alignment layer 16 (two sides embodiment), perhaps layer of surface orientor alignment layer 16 (single face embodiment) only alternatively.

When between the electrode of placing as shown in Figure 4 19 when liq-uid crystal bulk layer 18 (parallel with the confining substrate) applies external electric field (E ≠ 0), Figure 10 b, body of liquid crystal molecule 18 will be because its positive dielectric anisotropy will switch to second planar orientations that induce the field along the impressed field direction in the face.Yet the molecule of surface orientation device alignment layer 16 (being side chain) is because its negative dielectric anisotropy causes keeping its first initial planar orientation, and this first initial planar orientation is improved by impressed field and stablizes.In other words, when when layer 16 applies electric field, the molecule of surface orientation device alignment layer 16 (being side chain) will can not switch.When removing outfield (E=0), the molecule (being side chain) with surface orientation device alignment layer 16 of first planar orientations will promote to get back to its initial field-free plane first direction of orientation from the quick relaxation of second planar orientation that induce the field of body of liquid crystal molecule 18.

Formula XXXIII-XLV is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (in the face switch liquid crystal device).As mentioned above, these polymkeric substance comprise the side chain that demonstrates permanent and/or the dipole moment of inducing, and described dipole moment provides negative dielectric anisotropy with orderly phase form.

The person skilled in the art is well known that, do not use polymkeric substance, the side chain of formula XXXIII-XLV can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

The example of the suitable body of liquid crystal layer material that has positive dielectric anisotropy and be suitable for using in the above-described embodiment is, E44 (Δ ε=+ 16.8), E9 (Δ ε=+ 16.5) and E70A (Δ ε=+ 10.8), all these are the nematic liquid crystalline material by the BDH/Merck supply.

Switching the another kind of of liquid crystal device in of the present invention is following device like embodiment, this device comprises body of liquid crystal that demonstrates negative dielectric anisotropy (Δ ε＜0) and the one deck at least that demonstrates positive dielectric anisotropy (Δ ε＞0), preferred two layers of surface orientor alignment layer.

Formula XLVI-LXII is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (in the face switch liquid crystal device).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain demonstrates dipole moment permanent and/or that induce, and described dipole moment provides positive dielectric anisotropy with orderly phase form.

Formula XLVI formula XLVII

Formula XLVIII formula IL

Formula L formula LI

Formula LII formula LIII

Formula LIV formula LV

Formula LVI formula LVII

Formula LVIII formula LIX

Formula LX formula LXI

Formula LXII

Formula LXIII-LXVII is the further example that is suitable for providing the surface orientation device alignment layer material of initial field-free plane calibration in above-mentioned embodiment (in the face switch liquid crystal device).These polymkeric substance comprise side chain (S ₁) and side chain (S ₃), described side chain (S ₁) demonstrating dipole moment permanent and/or that induce, described dipole moment provides positive dielectric anisotropy with orderly phase form, described side chain (S ₃) do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy is not provided.

Formula LXIII formula LXIV

Formula LXV

Formula LXVI formula LXVII

In above-described embodiment, be suitable for representing with formula LXVIII as the instantiation of this base polymer of surface orientation device alignment layer material.

Formula LXVIII

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula XLVI-LXVIII can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

The example of the body of liquid crystal layer material that has negative dielectric anisotropy and be suitable for using in the above-described embodiment is, the potpourri of MLC6608 (Δ ε=-4.2) and MBBA (Δ ε=-0.8), the potpourri of MLC6884 (Δ ε=-5.0) and MBBA (Δ ε=-0.8), and the potpourri of MDA98-3099 (Δ ε=-6) and MBBA (Δ ε=-0.8), all these are the nematic liquid crystalline material by the Merck supply.

2. the same-sign of dielectric anisotropy

In second group of embodiment of device of the present invention, liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of same-sign.Switch liquid crystal device in the preferred face of described device.

A) switch liquid crystal device in the face

Second group of embodiment according to the present invention, in face, switch in the liquid crystal device, the molecular orientation of described body layer can directly be controlled by applying electric field, so that switch to second planar orientation that induce the field in the initial first planar orientation face, and (in the liq-uid crystal bulk layer) described surface orientation device has described preferred orientation (being called the planar orientation that induce preferred field) at described suprabasil orthogonal projection (the surface orientation device that is called as projection) in the geometric surface parallel with described substrate.

In of the present invention interior switching device, the direction of parallel with the confining substrate (promptly along liq-uid crystal bulk layer) applies electric field.

The embodiment of switching liquid crystal device in of the present invention is that wherein body of liquid crystal and surface orientation device alignment layer all demonstrate the device of positive dielectric anisotropy (Δ ε＞0), and described surface orientation device alignment layer is applied on the inside surface of substrate of restriction liq-uid crystal bulk layer.

In this embodiment, the molecule of surface orientation device alignment layer (being side chain) is with respect to the confining substrate surface, have the initial planar orientation on first direction, thereby cause under field-free state (E=0) plane or the calibrating crystal body molecule on plane basically.Preferred folk prescription is to wipe surfaces orientor alignment layer, to obtain the direction of orientation on preferred field-free first plane.

This device can comprise two layers of surface orientor alignment layer (two sides embodiment), perhaps layer of surface orientor alignment layer (single face embodiment) only alternatively.

When between the electrode when liq-uid crystal bulk layer (parallel with the confining substrate) applies external electric field (E ≠ 0), the body of liquid crystal molecule will be because its positive dielectric anisotropy will switch to second planar orientations that induce the field along the impressed field direction in the face.When along this layer and when being parallel to the confining substrate and applying electric field, the molecule of surface orientation device alignment layer (being side chain) is because its positive dielectric anisotropy and also will switch to second direction of orientation that induce the field in the face.Molecular switchable (being side chain) will promote to switch to second planar orientations that it is induced fast from the first field-free planar orientations of body of liquid crystal molecule in the face of surface orientation device alignment layer.Therefore, under lower impressed voltage, the body of liquid crystal molecule switches to the field direction of orientation of inducing and switches in the face faster than the liquid crystal device (as shown in Figure 3) of the prior art of the surface orientation device alignment layer with non-switching in the case.Yet this is in interior switching of face that the surface orientation device alignment layer that should be noted that this device of the present invention in the context does not mediate the body of liquid crystal molecule, and this orientation can directly be controlled by dielectric coupling.Surface orientation device alignment layer does not drive, but only promotes described interior body to switch.

Can have positive dielectric anisotropy in 1 to 30 scope and surface orientation device alignment layer according to the liq-uid crystal bulk layer of the device of described embodiment and can have positive dielectric anisotropy in 1 to 30 scope.

It is believed that if compare the positive dielectric anisotropy of surface orientation device alignment layer has big on the occasion of (corrigendum), and is preferably much bigger, then is favourable with the positive dielectric anisotropy of liq-uid crystal bulk layer.

Formula XLVI-LXVIII is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (in the face switch liquid crystal device).As mentioned above, these polymkeric substance comprise the side chain that demonstrates permanent and/or the dipole moment of inducing, and described dipole moment provides positive dielectric anisotropy with orderly phase form.

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula XLVI-LXVIII can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

According to the present invention, in face, switch in the liquid crystal device (it has the surface orientation device alignment layer and the liq-uid crystal bulk layer of the dielectric anisotropy of the same-sign of demonstrating), can advantageously use two electrod- arrays 20,21, each array is made up of 2 interdigital electrodes 22, wherein arrange described interdigital electrode, so that obtainable electric field is substantially perpendicular to obtainable electric field (Figure 11) in second electrod-array 21 in first electrod-array 20.Each array 20,21 is applied in the confining substrate 23.In this embodiment, the two takes place and can realize easily the response time of weak point in the switching of body of liquid crystal molecule and relaxation when having extra electric field.

Embodiment is like liquid crystal device another kind of according to switching in of the present invention, wherein liq-uid crystal bulk layer and surface orientation device alignment layer the two all demonstrate the device of negative dielectric anisotropy (Δ ε＜0).

When (promptly along liq-uid crystal bulk layer, parallel with the confining substrate) when applying external electric field (E ≠ 0), the body of liquid crystal molecule is because its negative dielectric anisotropy causes switching to second planar orientations that induce the field vertical with the direction of extra electric field in the first field-free planar orientations face.When along this layer and when being parallel to the confining substrate and applying electric field, the molecule of surface orientation device alignment layer (being side chain) will be because its negative dielectric anisotropy also will switch to second direction of orientation that induce the field in the first field-free planar orientations face.Molecular switchable (being side chain) therefore will promote to switch to second planar orientations that it is induced fast from the first field-free planar orientations of body of liquid crystal molecule in the face of surface orientation device alignment layer.Therefore, the body of liquid crystal molecule switches to the field direction of orientation of inducing and switches in the face faster than the liquid crystal device of the corresponding prior art of the surface orientation device alignment layer with non-switching in the case.Equally, should be noted that herein the surface orientation device alignment layer of this device of the present invention does not mediate interior switching of face of body of liquid crystal molecule, it only promotes described switching.

Can have negative dielectric anisotropy in-6 to-1 scope and surperficial alignment layer according to the liq-uid crystal bulk layer of the device of this embodiment and can have the dielectric anisotropy of bearing in-6 to-1 scope.

It is believed that the negative dielectric anisotropy of surface orientation device alignment layer has big negative value (more negative), and is preferably much bigger, then is favourable if compare with the negative dielectric anisotropy of liq-uid crystal bulk layer.

Formula XXXIII-XLV is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (in the face switch liquid crystal device).As mentioned above, these polymkeric substance comprise the side chain that demonstrates permanent and/or the dipole moment of inducing, and described dipole moment provides negative dielectric anisotropy with orderly phase form.

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula XXXIII-XLV can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

The example of the body of liquid crystal layer material that has negative dielectric anisotropy and be suitable for using in the above-described embodiment is, the potpourri of MLC6608 (Δ ε=-4.2) and MBBA (Δ ε=-0.8), the potpourri of MLC6884 (Δ ε=-5.0) and MBBA (Δ ε=-0.8), and the potpourri of MDA98-3099 (Δ ε=-6) and MBBA (Δ ε=-0.8), all these are the nematic liquid crystalline material by the Merck supply.

It should be noted that, demonstrating the surface orientation device alignment layer of dielectric anisotropy of same-sign and the combination of liq-uid crystal bulk layer also is available and favourable for (the following stated) face switches liquid crystal device outward, more outstanding although the influence of the rise time of reducing is switched in face the liquid crystal device.Therefore, wherein liq-uid crystal bulk layer and the surface orientation device alignment layer device of the present invention that demonstrates the dielectric anisotropy of same-sign preferably switches liquid crystal device in the face.

B) face switches liquid crystal device outward

Second group of embodiment according to the present invention, outside face, switch in the liquid crystal device, the molecular orientation of described body layer can directly be controlled by applying electric field, so that initial vertical oriented surface switches to the planar orientation that induce the field outward, and (in the liq-uid crystal bulk layer) described surface orientation device has described preferred orientation (being called the planar orientation that induce preferred field) at the suprabasil orthogonal projection of confining (the surface orientation device that is called as projection) in the geometric surface parallel with described substrate.

Switch in the liquid crystal device outside of the present invention, the direction of vertical with the confining substrate (promptly vertical with liq-uid crystal bulk layer) applies electric field.

Figure 12 illustrates under field-free state (E=0), according to an of the present invention outer part of switching the embodiment of liquid crystal device 24, wherein surface orientation device alignment layer 25 (showing only one deck) and body of liquid crystal 26 all demonstrate negative dielectric anisotropy (Δ ε＜0), and described surface orientation device alignment layer 25 is applied on the inside surface of the substrate that limits liq-uid crystal bulk layer 26.

In this embodiment, the molecule of surface orientation device alignment layer 25 (being side chain) has initial vertical orientated with respect to the confining substrate surface, thereby cause under field-free state (E=0), the body of liquid crystal molecule 26 of vertical or perpendicular calibration, as shown in figure 12.Also preferred folk prescription is to wipe surfaces orientor alignment layer 25, the preferred orientations of the plane calibration of inducing with the field that obtains body of liquid crystal molecule 26.

This device can or comprise two layers of surface orientor alignment layer (two sides embodiment), perhaps layer of surface orientor alignment layer (single face embodiment) only.

When applying outfield (E ≠ 0) perpendicular to liq-uid crystal bulk layer 26 between the electrode on the inside surface of confining substrate 27, body of liquid crystal molecule 25 is because the planar orientation that induce the field that its negative dielectric anisotropy causes face to switch to outward to be determined by the wiping direction.

The molecule of surface orientation device alignment layer 25 (being side chain) is because the planar orientation that induce the field that its negative dielectric anisotropy causes the face of going back to switch to outward to be determined by the wiping direction.The face of surface orientation device alignment layer 25 switches the field-free vertical orientated planar orientation of inducing that switches to fast that molecule (being side chain) therefore promotes body of liquid crystal molecule 26 outward.Therefore, under lower impressed voltage, body of liquid crystal molecule 26 switches from field-free vertical orientated switching to outside the face of planar orientation faster than the liquid crystal device of the prior art of the surface orientation device alignment layer with non-switching of inducing the field.Yet, should be noted that according to the present invention the face that the surface orientation device alignment layer 25 of described device does not mediate body of liquid crystal molecule 26 switches outward, this orientation can directly be controlled by dielectric coupling by impressed field.Surface orientation device alignment layer 25 only promotes described outer the switching.

Can have negative dielectric anisotropy in-6 to-1 scope and surface orientation device alignment layer 25 according to the liq-uid crystal bulk layer 26 of the device of described embodiment and can have the dielectric anisotropy of bearing in-6 to-1 scope.

It is believed that surface orientation device alignment layer 25 has big negative value (more negative), and is preferably much bigger, then is favourable if compare with the negative dielectric anisotropy of body of liquid crystal 26.

Formula LXIX-LXXII is the example that is suitable for providing the surface orientation device calibration materials of initial field-free vertical calibration in above-mentioned embodiment (switching liquid crystal device outside the face).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain demonstrates dipole moment permanent and/or that induce, and described dipole moment provides negative dielectric anisotropy with orderly phase form.

Formula LXIX

Formula LXX

Formula LXXI

Formula LXXII

Formula LXXIII representative is suitable for providing the additional examples of the surface orientation device alignment layer material of initial field-free vertical calibration in above-mentioned embodiment (switching liquid crystal device outside the face).These polymkeric substance comprise side chain (S ₁) and side chain (S ₃), described side chain (S ₁) demonstrating dipole moment permanent and/or that induce, described dipole moment provides negative dielectric anisotropy with orderly phase form, described side chain (S ₃) do not demonstrate any permanent and/or dipole moment of inducing, and therefore any dielectric anisotropy is not provided.

Formula LXXIII formula LXXIV

In above-described embodiment, be suitable for representing with formula LXXIV as the instantiation of this base polymer of surface orientation device alignment layer material.

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula LXIX-LXXIV can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

Outside face, switch like liquid crystal device another kind of in the embodiment according to second group of embodiment of the present invention, the molecular orientation of described body layer can directly be controlled by applying electric field, so that initial planar orientation face switches to vertical orientated that the field induces outward, and the orthogonal projection (the surface orientation device that be called as projection) of (in the liq-uid crystal bulk layer) described surface orientation device on the geometrical plane vertical with described substrate has described preferred orientation (be called preferred field induce vertical orientated).

Figure 13 shows under field-free state (E=0), according to an of the present invention outer part of switching the embodiment of liquid crystal device 28, wherein surface orientation device alignment layer 29 (only showing one deck) and body of liquid crystal 30 the two all demonstrate positive anisotropy (Δ ε＞0), described surface orientation device alignment layer 29 is applied on the inside surface of substrate of restriction liq-uid crystal bulk layer 30.

In this embodiment, the molecule of surface orientation device alignment layer 29 (being side chain) has initial planar orientation with respect to the confining substrate surface, thereby causes under field-free state (E=0), the plane or the body of liquid crystal molecule 30 of plane calibration basically.Also preferred folk prescription is to wipe surfaces orientor alignment layer 29, with the preferred orientation of the field-free plane calibration that obtains body of liquid crystal molecule 30.

This device can comprise or two layers of surface orientor alignment layer 29 (two sides embodiment) or layer of surface orientor alignment layer 29 (single face embodiment) only.

When applying external electric field (E ≠ 0) perpendicular to liq-uid crystal bulk layer 30 between the electrode on the inside surface of confining substrate 31, body of liquid crystal molecule 30 is because its positive anisotropy causes face to switch to vertical orientated that the field induces outward.

When applying electric field perpendicular to the confining substrate, the molecule of surface orientation device alignment layer 29 (being side chain) since its positive dielectric anisotropy also face is switched to outward the field induce vertical orientated.Therefore the outer molecule (being side chain) that switches of the face of surface orientation device alignment layer 29 will promote to switch to induce vertical orientated fast from the field-free planar orientation of body of liquid crystal molecule 30.Therefore, under lower impressed voltage, body of liquid crystal molecule 30 switches outside field-free planar orientation switches to the face of liquid crystal device of the vertical orientated prior art faster than the surface orientation device alignment layer with non-switching of inducing the field.Yet, should be noted that the face that the surface orientation device alignment layer 29 of device of the present invention does not mediate body of liquid crystal molecule 30 switches outward, this orientation can directly be controlled by dielectric coupling by impressed field.Surface orientation device alignment layer 29 only promotes described outer the switching.

Can have positive dielectric anisotropy in 1 to 30 scope and surface orientation device alignment layer 29 according to the liq-uid crystal bulk layer 30 of the device of described embodiment and can have positive dielectric anisotropy in 1 to 30 scope.

It is believed that if compare the positive dielectric anisotropy of surface orientation device alignment layer 29 has big on the occasion of (corrigendum), and is preferably much bigger, then is favourable with the positive dielectric anisotropy of body of liquid crystal 30.

Formula XLVI-LXVIII is the example that is suitable for providing the surface orientation device calibration materials of initial field-free plane calibration in above-mentioned embodiment (switching liquid crystal device outside the face).As mentioned above, these polymkeric substance comprise the side chain that demonstrates permanent and/or the dipole moment of inducing, and described dipole moment provides positive dielectric anisotropy with orderly phase form.

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula XLVI-LXVIII can be connected to solid surface by chemistry, for example contain on gold surface, silica surface or the glass surface of silanol, form the suitable material that is suitable for as the surface orientation device alignment layer in the device of the present invention.

The variant of described up to now first and second groups of embodiments of device is following device according to the present invention, and described device comprises the two layers of surface orientor alignment layer of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.It is believed that this class device provides short total response time, especially switch liquid crystal device outward for face, time delay is short.

Figure 14 shows according to an of the present invention outer part of switching the embodiment of liquid crystal device 32, and wherein (with regard to dielectric anisotropy) asymmetric surface orientation device alignment layer 33,34 is applied on the inside surface of the substrate that limits liq-uid crystal bulk layer 35.Body of liquid crystal 35 demonstrates negative dielectric anisotropy (Δ ε＜0) and first surface orientor alignment layer 33 demonstrates negative dielectric anisotropy (Δ ε＜0) and second surface orientor alignment layer 34 demonstrates positive dielectric anisotropy (Δ ε＞0).

In this embodiment, the molecule of surface orientation device alignment layer 33,34 (being side chain) has initial vertical orientated with respect to the confining substrate surface, thereby cause under field-free state (E=0), the body of liquid crystal molecule 35 of vertical or perpendicular calibration is shown in Figure 14 a.Also preferred folk prescription is to wipe surfaces orientor alignment layer 33,34, the preferred orientation of the plane calibration of inducing with the field that obtains body of liquid crystal molecule 35.

When between the suprabasil electrode 36 of confining, applying external electric field (E ≠ 0) perpendicular to liq-uid crystal bulk layer 35, induce the flexural deformation in liq-uid crystal bulk layer 35, shown in Figure 14 b, thereby obtain crooked electricity (flexoelectric) polarization P _F1Extra electric field is coupled on the meander electrodeization and depends on the polarity of extra electric field, and flexural deformation will increase or descend, and replys thereby obtain linear photoconductor.

Figure 15 shows according to an of the present invention outer part of switching the embodiment of liquid crystal device 37, and wherein (with regard to dielectric anisotropy) asymmetric surface orientation device alignment layer 38,39 is applied on the inside surface of the substrate that limits liq-uid crystal bulk layer 40.Body of liquid crystal 40 demonstrates positive dielectric anisotropy (Δ ε＞0) and first surface orientor alignment layer 38 demonstrates positive dielectric anisotropy (Δ ε＞0) and second surface orientor alignment layer 39 demonstrates negative dielectric anisotropy (Δ ε＜0).

In this embodiment, the molecule of surface orientation device alignment layer 38,39 (being side chain) has initial planar orientation with respect to the confining substrate surface, thereby cause under field-free state (E=0), the plane or the body of liquid crystal molecule 40 of plane calibration basically are shown in Figure 15 a.Also preferred folk prescription is to wipe surfaces orientor alignment layer 38,39, with the preferred orientation of the field-free plane calibration that obtains body of liquid crystal molecule 40.

When between the suprabasil electrode 41 of confining, applying external electric field (E ≠ 0) perpendicular to liq-uid crystal bulk layer 40, induce the inclination and distortion in liq-uid crystal bulk layer 40, shown in Figure 15 b, thereby obtain meander electrode P _F1Extra electric field is coupled on the meander electrodeization and depends on the polarity of extra electric field, and inclination and distortion will increase or descend, and replys thereby obtain linear photoconductor.

3. demonstrate the structure division of surface orientation device alignment layer of the dielectric anisotropy of contrary sign

In the 3rd group of embodiment of the device according to the present invention, surface orientation device alignment layer comprises the structure division of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.It is believed that for switch in the face liquid crystal device and face switch outward liquid crystal device the two, this class device provides short time delay and short rise time.

The described structure division that it is believed that the dielectric anisotropy (Δ ε) that demonstrates contrary sign preferably should be evenly distributed in the surface orientation device alignment layer.

Can comprise or two layers of surface orientor alignment layer (two sides embodiment) or layer of surface orientor alignment layer (single face embodiment) only according to the device of the 3rd group of embodiment.

Can use the material that for example contains dimer chemistry structure, described dimer chemistry structure has first structure division of positive dielectric anisotropy (Δ ε＞0) and second structure division of the dielectric anisotropy of bearing (Δ ε＜0), obtain surface orientation device alignment layer, described surface orientation device alignment layer comprises the structure division of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.

Formula LXXV represents to be suitable for to provide the example of the surface orientation device alignment layer material of initial field-free plane calibration in above-mentioned embodiment (switching liquid crystal device outside the face or in the face).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain has dimeric structure, each side chain comprises first structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides positive dielectric anisotropy with orderly phase form, with second structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides negative dielectric anisotropy with orderly phase form.

Formula LXXV

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula LXXV can be connected to solid surface by chemistry, for example contains on gold surface, silica surface or the glass surface of silanol, forms the suitable material that is suitable for as surface orientation device alignment layer.

Formula LXXVI-LXXX is the example that is suitable for switching the surface orientation device alignment layer material that initial field-free vertical calibration is provided in the liquid crystal device outside the face of above-mentioned embodiment.These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain has dimeric structure, each side chain comprises first structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides positive dielectric anisotropy with orderly phase form, with second structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides negative dielectric anisotropy with orderly phase form.

Formula LXXVI

Formula LXXVII

Formula LXXVIII

Formula LXXIX

Formula LXXX

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula LXXVI-LXXX can be connected to solid surface by chemistry, for example contains on gold surface, silica surface or the glass surface of silanol, forms the suitable material that is suitable for as surface orientation device alignment layer.

Figure 16 shows according to an of the present invention outer part of switching the embodiment of liquid crystal device 42, described device has initial field-free vertical orientated and comprise surface orientation device alignment layer (showing only one deck), it is applied on the substrate surface 43, have dimeric structure, described dimeric structure comprises have positive dielectric anisotropy first structure division 44 of (Δ ε＞0) and second structure division 45 of negative dielectric anisotropy (Δ ε＜0).Liq-uid crystal bulk layer 46 has negative dielectric anisotropy (Δ ε＜0).

Figure 16 a shows field-free state (E=0) and Figure 16 b shows the state (E ≠ 0) that induce the field.

The material that contains the tripolymer chemical constitution also can be used in the 3rd group of embodiment of the present invention, described tripolymer chemical constitution has first structure division of positive dielectric anisotropy (Δ ε＞0), second structure division of negative dielectric anisotropy (Δ ε＜0) and or the 3rd structure division of the dielectric anisotropy of (Δ ε＞0) or negative (Δ ε＜0) just.Compare with first and second structure divisions, the 3rd structure division can be similar or different.Therefore, can in the device of the 3rd group of embodiment of the present invention, use the chemical constitution that contains two or more structure divisions, wherein each structure division demonstrates or the dielectric anisotropy of plus or minus and two dielectric anisotropies that demonstrate contrary sign in described three structure divisions.

Formula LXXXI-LXXXIII is the example that is suitable for providing the surface orientation device alignment layer material of initial field-free plane calibration in above-mentioned embodiment (outside the face or in the face switch liquid crystal device).These polymkeric substance comprise the side chain (S that is chemically bonded on the main polymer chain (Z) ₁), described side chain has the tripolymer structure, each side chain comprises first structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides positive dielectric anisotropy (Δ ε＞0) with orderly phase form, demonstrate second structure division of permanent and/or the dipole moment of inducing, described dipole moment provides negative dielectric anisotropy (Δ ε＜0) with orderly phase form, with the 3rd structure division that demonstrates permanent and/or the dipole moment of inducing, described dipole moment provides with orderly phase form or the dielectric anisotropy of (Δ ε＞0) or negative (Δ ε＜0) just.

Formula LXXXI

Formula LXXXII

Formula LXXXIII

Those skilled in the art are well known that, do not use polymkeric substance, the side chain of formula LXXXI-LXXXIII can be connected to solid surface by chemistry, for example contains on gold surface, silica surface or the glass surface of silanol, forms the suitable material that is suitable for as surface orientation device alignment layer.

Figure 17 shows according to an of the present invention outer part of switching the embodiment of liquid crystal device 47, described device has initial field-free planar orientation and comprises surface orientation device alignment layer (showing only one deck), it is applied on the substrate surface 48, has the tripolymer structure, described tripolymer structure comprises first structure division 49 of positive dielectric anisotropy (Δ ε＞0), the 3rd structure division of second structure division 50 of negative dielectric anisotropy (Δ ε＜0) and positive dielectric anisotropy (Δ ε＞0).Liq-uid crystal bulk layer 52 has positive dielectric anisotropy (Δ ε＞0).

Figure 17 a shows field-free state (E=0) and Figure 17 b shows the state (E ≠ 0) that induce the field.

Embodiment

Used thickness is the liquid crystal display glass substrate of 1.10mm.It is 80 Ω/cm that substrate one side provides surface resistance ²Indium tin oxide target (ITO) layer (electrode material).Use the known conventional photolithographic methods of those skilled in the art, addressing electrode structures is provided.Substrate of glass is cut into the sheet material that is of a size of 9.5 * 12.5mm, and milled border.Also use the substrate of glass that is of a size of 25.4 * 25.4mm.

Then, in ultra sonic bath, washing substrate several in distilled water, drying is washed 2 times in isopropyl alcohol then.Afterwards substrate is moved into the indoor of cleaning.

With being dissolved in the ITO side that the interior concentration of tetrahydrofuran (THF) is the surface orientation device alignment layer material spin coating substrate of about 0.1% (w/w) (testing the concentration of maximum 0.5%w/w).Speed is 3000-4000rpm and was coated with in 30 seconds.

After coating, the heating substrate is about 5-10 minute under 125 ℃ temperature, removes and desolvates (THF), and form alignment layer.Can or carry out drying on the hot plate and/or under the vacuum in baking oven.Make the substrate cooling then.

Should be noted that two-step approach test also obtains acceptable result, described two-step approach is included in 60 ℃ of heating about 5-10 minute down, then heats about 10-30 minute down at 130 ℃.Yet, be noted that the temperature that surpasses room temperature is optional for drying steps in principle.

Use the roller diameter of 120mm, the drum speed of 300rpm, the accumulation contact length of the linear velocity of 15mm/sec and about 0.5mm, the surface orientation device alignment layer that on the ITO layer, applies with the nylon cloth rubbing down.All substrates of rubbing down in the same direction.

Afterwards, two edges, in the string of a musical instrument (string), use UV-glue (NorlandNOA68) and separant (spacer), two substrates are placed in the unit together, one of them substrate Rotate 180 ° makes rubbing down direction antiparallel in this unit.Can be the separant that on this cell surface, sprays from alcohol dispersion liquid for the method that substitutes.This unit was placed under pressure in the UV exposure box 15 minutes.Little cable is ultrasonically welded on each ITO surface of this unit.

Then, by capillary force, the nematic crystal that will be in isotropic phase is incorporated in this unit (this can have or do not have under the situation of the vacuum of adding and carry out).

Should be noted that above-described device is simple relatively type.Device can have much bigger size and can for example pass through to use passive matrix addressing class or the addressing by different way of active array addressing class.In these cases, comprise the step that involves complicated microelectronics production stage.In all following embodiment, before using solvent, by reaction dissolvent being flowed through contain the shorter chromatogram column available from the ICN Alumina N super 1 of ICN Biomedicals GmbH Germany, dry solvent.

In all following embodiment, the known standard reaction of those skilled in the art is used for the preparation of polymkeric substance.

Owing to the statistics reason, maximum in the following embodiments functionality is 86%.Therefore, minimum 14% initial hydroxyl still keeps after reaction is finished.

Embodiment 1: the face with surface orientation device alignment layer of the stable vertical calibration of electricity switches liquid crystal device outward

The preparation of surface orientation device alignment layer material

In the 100ml flask, with 0.70g4`-(11,11-diethoxy undecane oxygen base)-xenyl-4-carbon nitrile (side chain precursor I) is (referring to D Lacey etc., MacromolecularChemistry and Physics 200,1222-1231 (1999)), 0.081g octanal, 0.198g polyvinyl alcohol (PVA) (PVA) (number-average molecular weight is about 15000g/mol) and 0.10g p-toluenesulfonic acid (TsOH) are dissolved in the dry N of 20ml, in the dinethylformamide (DMF), and under about 55 ℃, stirred 24 hours.

Then reaction mixture is poured in the 150ml methyl alcohol, and polymer precipitation.Collecting precipitation, and be dissolved in the 5ml chloroform, and in 100ml methyl alcohol, precipitate again, precipitate again repeatedly 2 times.

Productive rate is 0.29g polymkeric substance (that is, the consumption based on the polyvinyl alcohol (PVA) that is added is calculated as 40%).Loss is to cause owing to the polymkeric substance of low molar mass in comprehensive process operation (promptly precipitating operation) is removed.

Resulting polymers ¹H-NMR spectrum is consistent with the structure A of flow process I.The side chain mol ratio I/ octanal in polymkeric substance that uses NMR to measure is found to be 2/1 (o/n the among=structure A).In addition, (o+n)/p is found to be about 42/16.

The side chain that is formed by side chain precursor I passes through-(CH ₂) ₁₀The interval atom of-form is connected on the main polymer chain.

Flow process I

Make liquid crystal device of the present invention

As mentioned above, with the polymer A (=formula XIX) for preparing as mentioned above, the ITO side of coat substrates.Yet, should be noted that any structure that can use in this embodiment according among the formula I-XXXII.

Folk prescription is to wiping polymeric layer (about 100nm) very gently, and the internal compensation of induced polymer cooperates the little pre-tilt of side chain and assembles this unit afterwards.

Use nematic mixture M BBA/MLC6608 (Merck, Germany) then, 40/60wt% fills interlayer element (cell gap is about 3 microns), wherein Δ ε=-4.2 of Δ ε=-0.8 of MBBA and MLC6608.

In this unit, polymeric layer serves as surface orientation device alignment layer.

Observe the calibration of the unit cool to room temperature after by polarizing microscope, be found to be even vertical.

In the device that contains polarizing microscope, photodetector, oscillograph and pulse producer, measure to reply and rise and time delay.

Figure 18 has described and has applied under low frequency (about 1Hz) unipolar pulse, and the photoelectricity with unit of vertical calibration is replied.Under the voltage (U) of 9.2V, are respectively measured rising and time delay about 1.9 and 3.8ms.Therefore, measured time delay is than lacking about 5 times the time delay that the face with initial vertical calibration switches common measurement in the liquid crystal cells outward.

Embodiment 2: the face with surface orientation device alignment layer of the stable vertical calibration of electricity switches liquid crystal device outward

Repeat embodiment 1, different is that with nematic mixture M BBA/MLC6884 (Merck, Germany), 40/60wt% fills interlayer element, wherein Δ ε=-0.8 of Δ ε=-5.0 of MLC6884 and MBBA.

As shown in figure 19, under the voltage (U) of 6.1V, are respectively measured rising and time delay about 2.5 and 1.8ms.

Embodiment 3: the face with surface orientation device alignment layer of the stable vertical calibration of electricity switches liquid crystal device outward

The preparation of surface orientation device alignment layer material

In the 100ml flask, with 0.11g4`-(11,11-diethoxy undecane oxygen base)-xenyl-4-carboxylic acid 4-ethoxy carbonyl phenyl ester (side chain precursor III), 0.07g4`-(11,11-diethoxy undecane oxygen base)-4`-11 carbon-10-thiazolinyl oxygen base biphenyl (side chain precursor VII), 0.018g octanal, 0.037gPVA (number-average molecular weight is about 15000g/mol) and 0.03g TsOH be dissolved among the dry DMF of 10ml, and stirred 48 hours down at about 55 ℃.

Then reaction mixture is poured in the 150ml methyl alcohol, and polymer precipitation.Collecting precipitation, and be dissolved in the 5ml chloroform, and in 100ml methyl alcohol, precipitate again, precipitate again repeatedly 2 times.

Productive rate is the 0.09g polymkeric substance.Loss is to cause owing to the polymkeric substance of low molar mass in the comprehensive process operation is removed.

Resulting polymers ¹H-NMR spectrum is consistent with the structure H of flow process II.

To pass through-(CH by the side chain that side chain precursor III forms ₂) ₁₀The interval atom of-form is connected on the main polymer chain, and will be passed through-(CH by the side chain that side chain precursor VII forms ₂) ₁₀The interval atom of-form is connected on the main polymer chain.

Flow process II

Make liquid crystal device of the present invention

Repeat embodiment 1, different is that the polymkeric substance H (=formula XXXII) that usefulness prepares as mentioned above is the ITO side of coat substrates as described above.Yet, not wiping polymeric layer.In addition, the nematic material MLC6884 (Merck, Germany) with Δ ε=-5.0 fills interlayer element.

As shown in figure 20, under the voltage (U) of 5.2V, are respectively measured rising and time delay about 2.7 and 2.7ms.

Embodiment 4:

Face with surface orientation device alignment layer of the stable plane calibration of electricity switches liquid crystal device outward

The preparation of surface orientation device alignment layer material

In the 100ml flask, with 1.0g2-[4-(11,11-diethoxy-undecane oxygen base)-and 3-(4-ethoxyl phenenyl azo group) phenyl oxygen base] butyl propionate (side chain precursor IX), 0.205g octanal, 0.25gPVA (number-average molecular weight is about 15000g/mol) and 0.1gTsOH be dissolved in the 25ml dry THF, and stirred 24 hours down at about 60 ℃.

Then reaction mixture is poured in the 250ml methyl alcohol, and polymer precipitation.Collecting precipitation, and be dissolved in the 5ml chloroform, and in 100ml methyl alcohol, precipitate again, precipitate again repeatedly 2 times.

Productive rate is the 0.56g polymkeric substance.Loss is to cause owing to the polymkeric substance of low molar mass in the comprehensive process operation is removed.

Resulting polymers ¹H-NMR spectrum is consistent with the structure J of flow process III.The side chain mol ratio IX/ octanal in polymkeric substance that uses NMR to measure is found to be 1/1 (o/n the among=structure J).In addition, (o+n)/p is found to be about 43/18.

The side chain that is become by side chain precursor I X-shaped passes through-(CH ₂) ₁₀The interval atom of-form is connected on the main polymer chain.

Flow process XIII

Make liquid crystal device of the present invention

As mentioned above, with the polymkeric substance J (=formula XLIV) for preparing as mentioned above, the ITO side of coat substrates.Yet, should be noted that any structure that can use in this embodiment according among the formula XXXIII-XLV.

Folk prescription cooperates the uniform planar calibration of (mesogenic) side chain and assembles this unit afterwards with the internal compensation of guaranteeing polymkeric substance to wiping polymeric layer (about 100nm).

Use the nematic mixture E 7 (BDH/Merck) of Δ ε＞0 to fill interlayer element (cell gap is about 3 microns) then.

In this unit, polymeric layer serves as surface orientation device alignment layer.

Observe the calibration of the unit after cool to room temperature and be found to be uniform planar by polarizing microscope.

In the device that contains polarizing microscope, photodetector, oscillograph and pulse producer, measure rise time and time delay.

Applying under low frequency (about 1Hz) unipolar pulse, the photoelectricity with unit of plane calibration is replied, and finds to rise and be respectively about 0.5ms and 4ms time delay.

Embodiment 5:

Face with surface orientation device alignment layer of the stable plane calibration of electricity switches liquid crystal device outward

Repeat embodiment 4, different is to use the nematic material E70A (BDH/Merck) of Δ ε=+ 10.8 to fill interlayer element.

As shown in figure 21, under the voltage (U) of 5.6V, are respectively measured rising and time delay about 1.1 and 1.6ms.

Although described the present invention in detail with reference to specific embodiments of the present invention, for those skilled in the art, it is evident that, can under the situation that does not break away from the spirit and scope of the present invention, make various variations and change.

Claims (18)

1. liquid crystal device, it comprises liq-uid crystal bulk layer, there is the surface orientation device in the place at the liq-uid crystal bulk layer body surface, with comprise surface orientation device alignment layer, described surface orientation device alignment layer is included in the side chain of described body surface place for interacting and to arrange with liq-uid crystal bulk layer, so that help to obtain the preferred orientation of the surface orientation device of liq-uid crystal bulk layer, it is characterized in that each is directly actuated by dielectric coupling by electric field naturally for the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer.

2. the liquid crystal device of claim 1, wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign.

3. the liquid crystal device of claim 1, wherein liq-uid crystal bulk layer and surface orientation device alignment layer demonstrate the dielectric anisotropy (Δ ε) of same-sign.

4. the liquid crystal device of claim 1, it comprises the first and second surface orientation device alignment layers, wherein liq-uid crystal bulk layer and first surface orientor alignment layer demonstrate the dielectric anisotropy (Δ ε) of contrary sign and wherein liq-uid crystal bulk layer and second surface orientor alignment layer demonstrate the dielectric anisotropy (Δ ε) of same-sign.

5. the liquid crystal device of claim 1, wherein surface orientation device alignment layer comprises the structure division of the dielectric anisotropy (Δ ε) that demonstrates contrary sign.

6. the liquid crystal device of claim 2, further comprise the substrate of at least one restriction liq-uid crystal bulk layer, wherein said surface orientation device is in described suprabasil orthogonal projection, the surface orientation device that is called as projection, in the geometric surface parallel, has described preferred orientation with described substrate, be called preferred field-free planar orientation, can directly control with the molecular orientation of described liq-uid crystal bulk layer by applying electric field, so as the described preferred planar oriented surface of the surface orientation device of projection switch to outward the field induce vertical orientated.

7. the liquid crystal device of claim 2, further comprise the substrate of at least one restriction liq-uid crystal bulk layer, the orthogonal projection of wherein said surface orientation device on the geometrical plane vertical with described substrate, the surface orientation device that is called as projection, has described preferred orientation, being called preferred field-free molecular orientation vertical orientated and described liq-uid crystal bulk layer can directly control by applying electric field, so that the described preferred vertical orientation face of the surface orientation device of projection switches to the planar orientation that induce the field outward.

8. the liquid crystal device of claim 6, wherein the substrate perpendicular to described at least one restriction liq-uid crystal bulk layer applies electric field.

9. the liquid crystal device of claim 7, wherein the substrate perpendicular to described at least one restriction liq-uid crystal bulk layer applies electric field.

10. the liquid crystal device of claim 3, further comprise the substrate of at least one restriction liq-uid crystal bulk layer, can directly control with the molecular orientation of described liq-uid crystal bulk layer by applying electric field, so that switch to second planar orientation that induce the field in the first initial planar orientation face, and the orthogonal projection of described surface orientation device, the surface orientation device that is called as projection has described preferred orientation in the geometric surface parallel with described substrate, be called the planar orientation that induce preferred field.

11. the liquid crystal device of claim 10, the substrate that wherein is parallel to described at least one restriction liq-uid crystal bulk layer applies electric field.

12. any one liquid crystal device of claim 1-11, wherein liq-uid crystal bulk layer comprises nematic crystal.

13. any one liquid crystal device of claim 1-11, wherein surface orientation device alignment layer comprises the polymkeric substance that has main polymer chain and be connected to the side chain on the main polymer chain, and described main polymer chain does not have the ring structure of direct coupling and each side chain at least some side chains wherein:

(i) comprise by at least two phenyl that do not replace and/or replace that are selected from following coupling base coupling: the unit of carbon-carbon single bond (-), carbon-carbon double bonds (CH=CH-), the unit of carbon containing carbon triple bond (C ≡ C-), methylene ether unit (CH ₂O-), ethyleneether units (CH ₂CH ₂O-), ester units (COO-) and the azo unit (N=N-);

(ii) demonstrate dipole moment permanent and/or that induce, described dipole moment provides dielectric anisotropy with orderly phase form; With

(iii) be connected on the main polymer chain by at least two interval atoms.

14. the liquid crystal device of claim 12, wherein surface orientation device alignment layer comprises the polymkeric substance that has main polymer chain and be connected to the side chain on the main polymer chain, and described main polymer chain does not have the ring structure of direct coupling and each side chain at least some side chains wherein:

(i) comprise by at least two phenyl that do not replace and/or replace that are selected from following coupling base coupling: the unit of carbon-carbon single bond (-), carbon-carbon double bonds (CH=CH-), the unit of carbon containing carbon triple bond (C ≡ C-), methylene ether unit (CH ₂O-), ethyleneether units (CH ₂CH ₂O-), ester units (COO-) and the azo unit (N=N-);

(ii) demonstrate dipole moment permanent and/or that induce, described dipole moment provides dielectric anisotropy with orderly phase form; With

(iii) be connected on the main polymer chain by at least two interval atoms.

15. the liquid crystal device of claim 13, wherein polymkeric substance is a Pioloform, polyvinyl acetal.

16. the liquid crystal device of claim 14, wherein polymkeric substance is a Pioloform, polyvinyl acetal.

17. a method of making liquid crystal device, this method comprises the steps:

On the inside surface of at least one substrate, provide surface orientation device alignment layer and

Between two substrates, accompany liq-uid crystal bulk layer, there is the surface orientation device in described liq-uid crystal bulk layer at its body surface place, be included as in described body surface place and liq-uid crystal bulk layer with described surface orientation device alignment layer and interact and the side chain arranged, so that help to obtain the preferred orientation of the surface orientation device of body layer

It is characterized in that each is directly actuated by dielectric coupling by electric field naturally for the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer.

18. method of controlling liq-uid crystal bulk layer, this method comprises the steps: by using surface orientation device alignment layer, the calibrating crystal body layer, there is the surface orientation device in the place at the liq-uid crystal bulk layer body surface, wherein said surface orientation device alignment layer is included as at described body surface place and liq-uid crystal bulk layer and interacts and the side chain of arrangement, so that help to obtain the preferred orientation of the surface orientation device of liq-uid crystal bulk layer, it is characterized in that each is directly actuated by dielectric coupling by electric field naturally for the orientation of the described side chain of the molecular orientation of liq-uid crystal bulk layer and surface orientation device alignment layer.

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