JP2004219948A - Liquid crystal optical element and its manufacture method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid crystal optical element having high-speed responsibility, and to provide a manufacture method thereof. <P>SOLUTION: The liquid crystal optical element 10 has a configuration in which a substrate 12a, an electrode 14a, an alignment layer 16a, a liquid crystal layer 18, an alignment layer 16b, an electrode 14b and a substrate 12b are laminated in this order, and the liquid crystal layer 18 contains structures 20a, 20b. The structure 20a has the same length L1 with the thickness T1 of the liquid crystal layer 18 and both ends of the structure 20a are fixed to a pair of the alignment layers 16a, 16b, in other words, to liquid crystal layer holding parts. The structure 20b has a length L2 shorter than the thickness T1 of the liquid crystal layer 18 and is disposed in such a manner that one end thereof is fixed to either one side of a pair of the alignment layers 16a, 16b and the other side thereof is separated from the other end. Both of the structures 20a, 20b have side surfaces formed in a planar shape or in a curved shape. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a liquid crystal optical element and a method for manufacturing the same.
[0002]
[Prior art]
A liquid crystal optical element is an element that electrically controls light transmittance and reflectance using the optical rotation and birefringence of liquid crystal.
[0003]
A conventional example of such a liquid crystal optical element will be described with reference to FIG.
[0004]
The liquid crystal optical element 1 shown in FIG. 1 is a general one, and has a configuration in which a substrate 2a, an electrode 3a, an alignment film 4a, a liquid crystal layer 5, an alignment film 4b, an electrode 3b, and a substrate 2b are stacked in this order. The liquid crystal layer 5 is formed of a liquid crystal material such as a nematic liquid crystal or a ferroelectric liquid crystal. Reference numeral 6 denotes an AC power supply for driving the liquid crystal optical element 1.
[0005]
When light is incident from one of the substrates 2a in a state where a voltage is applied between the two electrodes 3a and 3b, the liquid crystal optical element 1 changes the alignment direction of the liquid crystal according to the applied voltage, and the input light is transmitted to the liquid crystal layer 5a. The birefringence phenomenon occurs in the inside, the phase is changed, and the light is emitted from the other substrate 2ba. Note that the light incident and exit directions may be opposite to those in FIG.
[0006]
If this output light is used, the liquid crystal optical element 1 having an optical phase modulation operation can be obtained. If a polarizer and an analyzer are arranged on both sides of the liquid crystal optical element 1, a light intensity modulation operation can be performed. Further, the liquid crystal driving element 1 is formed for each pixel, so that the liquid crystal optical element 1 as a liquid crystal display element (apparatus) can be obtained.
[0007]
In order to provide a high-speed response to such a liquid crystal optical element, it is preferable to use a ferroelectric liquid crystal or an anti-dielectric liquid crystal as a liquid crystal material.
[0008]
However, ferroelectric liquid crystals and anti-dielectric liquid crystals generally have many problems in practical use, such as low impact resistance, a narrow operating temperature range, and a large temperature dependency.
[0009]
For this reason, a nematic liquid crystal mode is used as a practical operation mode.
[0010]
However, since a normal nematic liquid crystal has a low response speed, there is a problem that it does not have an optical response characteristic at a video rate sufficient for displaying a general moving image.
[0011]
On the other hand, there is a π cell as an operation mode showing the fastest response in a nematic liquid crystal.
[0012]
However, the π cell requires the transition from the splay alignment to the bend alignment, has a low transition speed, and requires a special drive circuit for applying a high voltage for the transition. With.
[0013]
In order to eliminate these drawbacks of the π cell, a liquid crystal in which K33 / K11, which is the ratio of the elastic constant K11 representing spray and the elastic constant K33 representing bend, is 0.1 or more and 0.9 or less is used as a liquid crystal material. There has been proposed a liquid crystal optical element having a bend-shaped liquid crystal molecule alignment including a shape having a slight twist. According to this liquid crystal optical element, a special drive circuit for initial alignment transition is not required, and the initial alignment is completed in a short time by applying a low voltage (see Patent Document 1).
[0014]
[Patent Document 1]
JP-A-8-87013
[0015]
[Problems to be solved by the invention]
However, the liquid crystal optical element using the liquid crystal having a bend alignment structure operating at a low voltage as described above is intended to speed up the transition by selecting and using a liquid crystal material having specific characteristics. It can be said that the essential shortcomings of have remained.
[0016]
The present invention has been made in view of the above problems, and has as its object to provide a liquid crystal optical element having high-speed response and a method for manufacturing the same.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, a liquid crystal optical element according to the present invention is provided on a pair of substrates and a pair of electrodes respectively disposed on opposite surfaces of the pair of substrates and subjected to a surface alignment treatment. A liquid crystal optical element comprising a liquid crystal layer holding portion having: and a liquid crystal layer disposed between the liquid crystal layer holding portions, wherein the liquid crystal layer includes a structure extending in a thickness direction of the liquid crystal layer, The structure has a side surface formed in a flat shape or a curved shape curved in a direction orthogonal to the extending direction, and at least one end in the extending direction is fixed to the liquid crystal holding portion. It is characterized by.
[0018]
Thereby, the alignment state of the liquid crystal can be more effectively regulated by the contact between the liquid crystal and the structure, and a liquid crystal optical element having a high-speed response can be obtained.
[0019]
In this case, it is more preferable that the structure has a communication permitting structure that allows the liquid crystal portions located on both sides to communicate with each other via the structure. In particular, the liquid crystal material is injected to form the liquid crystal layer. In this case, a liquid crystal layer having a uniform liquid crystal structure and thickness can be easily obtained.
[0020]
Further, at this time, it is preferable that the structure is disposed such that one end in the extending direction is separated from the liquid crystal holding unit.
[0021]
Further, it is preferable that the structure is constituted by a plurality of cylindrical objects or one or more lattice objects having openings in the extending direction.
[0022]
Further, the structure may include one or two or more circling walls circling in parallel with the liquid crystal holding portion.
[0023]
In this case, it is preferable that the structure has a slit-shaped opening formed on a side surface extending in a direction in which the structure extends.
[0024]
Further, in this case, in a circumference unit that forms a virtual closed loop of the structure by circling in parallel with the liquid crystal holding unit, the total extension distance of the opening interval of the slit-shaped openings is the total length of the circumference unit. When it is formed to have a length equal to or less than の, the contact between the liquid crystal molecules and the structure can be sufficiently ensured, and the alignment state of the liquid crystal can be more effectively regulated.
[0025]
In this case, it is preferable that the liquid crystal layer is formed of one or more liquid crystal materials selected from the group consisting of a nematic liquid crystal, a cholesteric liquid crystal, and a smectic liquid crystal.
[0026]
At this time, the ratio (K33 / K11) of the bending elastic constant K33 to the spreading elastic constant K11 of the liquid crystal material is 1.7 or less, or the ratio of the spreading elastic constant K11 of the liquid crystal material is 15 (unit: pN) or less. If there is, it is preferable.
[0027]
Further, at least one of the pair of substrates of the liquid crystal optical element is made of a polycarbonate resin, a polyester resin, a polyacrylate resin, a polyethylene terephthalate resin, a polyether sulfone resin, an epoxy resin, an amorphous polyolefin resin, an acrylic ultraviolet curable resin. It is preferable to be formed of a material selected from the group consisting of glass and silicon.
[0028]
Further, it is preferable that the pair of alignment films are aligned in parallel by the surface alignment treatment.
[0029]
In addition, when the liquid crystal optical element further includes a phase compensator, an element having high contrast and a wide viewing angle can be obtained.
[0030]
Further, in the liquid crystal optical element according to the present invention, the pair of electrodes is a pixel electrode to which a voltage is applied for each pixel, and the structure is formed in a gap between adjacent pixel electrodes in a plan view state. It is characterized by being provided.
[0031]
As a result, a smooth moving image with no afterimage can be obtained as compared with a device using a conventional twisted nematic liquid crystal.
[0032]
In this case, when the structure is disposed on one or more of the pixel electrodes within a range occupying 60% or less of the total area of the pixel electrodes in a plan view, the aperture ratio is impaired. And a high-luminance image display can be obtained.
[0033]
Further, the method for manufacturing a liquid crystal optical element according to the present invention is the method for manufacturing a liquid crystal optical element described above, wherein the liquid crystal material and the reaction curable polymer material are provided on one side of the liquid crystal layer holding portion. And a step of patterning and curing the reactive curable polymer material to form the structure made of a cured product of the reactive curable polymer material.
[0034]
Thus, a structure having a desired form can be easily obtained.
[0035]
In this case, in the step of forming the structure, when the liquid crystal material is cured in a temperature environment of a nematic phase (a temperature at which the liquid crystal becomes a nematic phase), the liquid crystal layer can be formed of the nematic phase, and high-speed operation is possible. Π cells can be easily obtained.
[0036]
In this case, it is preferable that the reaction-curable polymer material is one or both of a monomer and an oligomer.
[0037]
At this time, it is preferable that the monomer or oligomer is one or two or more materials selected from the group consisting of acrylate, epoxy, epoxy acrylate, ester acrylate, and urethane acrylate.
[0038]
In this case, if the viscosity of the reaction-curable polymer material is 300 (unit: cps) or less, a structure having a desired form can be easily obtained.
[0039]
Further, in this case, in the application step, when a polymerization initiator is added to the mixture and used, the time required to produce a structure can be reduced.
[0040]
In this case, in the application step, when a colorant comprising a dye is added to the mixture and used, a high contrast can be obtained when an image display operation is performed.
[0041]
Further, in this case, the reaction-curable polymer material is a main chain polymer mainly containing a liquid crystal material in a main chain or a side chain polymer mainly containing a liquid crystal material in a side chain, It is suitable.
[0042]
In this case, in the step of forming the structural body, a material containing a liquid crystalline material is used as the reactive curable polymer material, and (1) before the patterning / curing process, or (2) the patterning / curing process. When an electric field is applied between the pair of electrodes before and during the patterning hardening process and at the time of the patterning hardening process, the liquid crystal material is aligned with the liquid crystal material. Can be performed more suitably.
[0043]
In this case, when an electric field is applied between the pair of electrodes before and after the patterning / curing process, the intensity of the electric field applied before the patterning / curing process is increased. When the intensity of the electric field applied during the treatment is higher than that, the liquid crystal alignment in a desired alignment state can be quickly controlled.
[0044]
At this time, the intensity of the electric field applied before the patterning hardening process is 1 (unit: V / μm) or more, and the intensity of the electric field applied at the time of the patterning hardening process is 0.5 (unit: V / μm). The following is preferable.
[0045]
In this case, in the step of forming the structure, it is preferable to perform patterning and hardening by patternwise exposing light from a light source through a photomask or drawing and exposing the light from the light source finely.
[0046]
In this case, it is preferable that the light source is a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a halogen lamp, or a laser.
[0047]
Further, in this case, after performing the pattern exposure or the drawing exposure, and further uniformly exposing the entire liquid crystal layer including the structure, an uncured portion of the reaction-curable polymer material that may remain after curing is obtained. Can be cured.
[0048]
In this case, when uniformly exposing the entire liquid crystal layer, it is preferable to apply an electric field having an intensity of 1 (unit: V / μm) or more between the pair of electrodes.
[0049]
In this case, the exposure area (S _P ), The total area of the liquid crystal layer including the exposed area (S _D ), The mass of the reactive curable polymer material to be applied (W _P ) And the mass of the liquid crystal material to be applied (W _LC Is adjusted so as to satisfy the following formula, the residual amount of the uncured portion of the cured reaction-curable polymer material after curing can be minimized.
[0050]
(Formula) S _P / S _D ≧ 1.5W _P / (W _P + W _LC )
In this case, it is preferable that the reaction curable polymer material is formed of a material having a contact angle with liquid crystal molecules constituting the liquid crystal layer of 50 ° or less in a state where the structure is formed. is there.
[0051]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of a liquid crystal optical element and a method of manufacturing the same according to the present invention (hereinafter, referred to as embodiments) will be described below with reference to the drawings.
First, a liquid crystal optical element according to a first example of the present embodiment will be described with reference to FIG.
[0052]
The basic configuration of the liquid crystal optical element according to the first example of the present embodiment is the same as that of the conventional liquid crystal optical element shown in FIG. 1 in the vertical direction) is different from the conventional liquid crystal optical element.
[0053]
That is, the liquid crystal optical element 10 according to the first example of the present embodiment has a configuration in which the substrate 12a, the electrode 14a, the alignment film 16a, the liquid crystal layer 18, the alignment film 16b, the electrode 14b, and the substrate 12b are stacked. , The liquid crystal layer 18 includes the structures 20a and 20b. Here, except for the liquid crystal layer 18, the substrate 12a, the electrode 14a, the alignment film 16a, the liquid crystal layer 18, the alignment film 16b, the electrode 14b, and the substrate 12b constitute a liquid crystal layer holding unit.
[0054]
The structure 20a has the same length (height) L1 as the thickness T1 of the liquid crystal layer 18, and both ends are fixed to the pair of alignment films 16a and 16b, in other words, to the liquid crystal layer holding portion.
The structure 20b has a length L2 shorter than the thickness T1 of the liquid crystal layer 18, and one end is fixed to one of the pair of alignment films 16a and 16b, and the other end of the structure 20b is connected to the other of the alignment films 16a and 16b. It is arranged with the other end separated. As long as the structure has a planar shape or a curved shape that is curved in a direction perpendicular to the thickness direction of the liquid crystal phase 18, the structure extends in a plan view (a state viewed from the thickness direction of the liquid crystal phase). The shape is not particularly limited. That is, the structure may be a rod-like or plate-like material like the structures 20a and 20b, or may be a lattice shape or a cylindrical shape described later. Note that, for example, when the liquid crystal optical element has an image display function, the structure may be a conical member or the like as long as it does not overlap the pixel region. The structure may be an aggregate of any one of the structures 20a and 20b, or may be a hybrid of these irregular structures.
[0055]
At least one of the substrates 12a and 12b is preferably a polycarbonate resin, a polyester resin, a polyacrylate resin, a polyethylene terephthalate resin, a polyethersulfone resin, an epoxy resin, an amorphous polyolefin resin, an acrylic ultraviolet curing resin, glass or silicon. It is formed of any material. In particular, it is preferable that both the substrates 12a and 12b are formed of a thin plastic material because the liquid crystal optical element 10 can have flexible characteristics.
[0056]
The electrodes 14a and 14b are formed using an appropriate transparent material such as ITO.
[0057]
The alignment films 16a and 16b are preferably made of, for example, polyimide resin, silicon oxide, polyvinyl alcohol resin, or the like, and are subjected to parallel alignment and anti-alignment using alignment processing methods such as rubbing, optical alignment, and oblique deposition. The alignment processing is performed in one of a parallel alignment and a twist alignment. In particular, the parallel alignment is preferable because a bend alignment cell having a hydrodynamic flow effect and operating at high speed can be easily realized.
[0058]
The liquid crystal layer 18 is formed of a liquid crystal material having a refractive index anisotropy that changes its alignment state with respect to an applied voltage (electric field). The liquid crystal molecules of the liquid crystal layer 18 easily bend at least in a state where a voltage is applied between the electrodes 14a and 14b due to wettability with the side surfaces of the structures 20a and 20b. As such a liquid crystal material, any of a nematic liquid crystal, a cholesteric liquid crystal, and a smectic liquid crystal, or a mixture of these liquid crystals can be used. In particular, when a nematic liquid crystal is used, a material having a ratio K33 / K11 of the spreading elastic coefficient K11 to the bending elastic coefficient K33 of 1.7 or less or a spreading elastic coefficient K11 of 15 (unit: pN) or less is used. It is preferable to use a selected material since liquid crystal alignment can be controlled at a low voltage and a bend alignment cell that operates at high speed can be easily realized.
[0059]
The members of the liquid crystal optical element 10, such as the substrates 12a and 12b, except for the structures 20a and 20b described above, can be manufactured by the usual method using the above-described materials. Note that materials and manufacturing methods used for the structures 20a and 20b will be described later.
[0060]
As shown in FIG. 2, the liquid crystal optical element 10 according to the first example of the present embodiment is a transmissive element in which light incident from the substrate 12a exits from the substrate 12b. The liquid crystal optical element 10 drives and controls the liquid crystal (liquid crystal molecules) of the liquid crystal layer 18 by applying a voltage between the electrodes 14a and 14b with an AC or DC power supply indicated by reference numeral 22. At this time, as described above, when the alignment films 16a and 16b are in a parallel alignment relationship, the liquid crystal of the liquid crystal layer 18 easily bends with the structures 20a and 20b in the liquid crystal layer 18, so that a low voltage is applied. And high-speed response can be obtained.
[0061]
Further, by providing a polarizer and an analyzer on both sides of the liquid crystal optical element 10, a light intensity modulation operation can be obtained.
[0062]
Further, by providing the liquid crystal optical element 10 with a phase compensator as an optical compensator, an element having high contrast and a wide viewing angle can be obtained.
[0063]
In addition, when the liquid crystal optical element 10 is formed with the structures 20a and 20b in advance at the time of manufacture and then injects a liquid crystal material to form a liquid crystal layer, the liquid crystal portions positioned on both sides of the structures 20a and 20b via the structures 20a and 20b Have a structure capable of communicating with each other (communication permitting structure), so that a uniform injection operation of the liquid crystal material can be easily performed.
[0064]
Next, a modified example of the liquid crystal optical element 10 will be described with reference to FIG.
[0065]
The basic configuration of the liquid crystal optical element 10a of the modification is the same as that of the liquid crystal optical element 10. Therefore, the same components are denoted by the same reference numerals as those of the liquid crystal optical element 10, and the structure, material, manufacturing method, etc. A duplicate description of will be omitted, and only the characteristic components will be described in detail. The same applies to other examples described later.
[0066]
The liquid crystal optical element 10a differs from the liquid crystal optical element 10 in that an electrode 14c provided between the substrate 12a and the alignment film 16a is formed of a reflective metal material such as aluminum.
[0067]
The liquid crystal optical element 10a is a reflection type element, and light incident from the substrate 12b is reflected by the electrode 14c and emitted again from the substrate 12b.
[0068]
Next, modified examples of the structure of the liquid crystal optical element 10 will be described with reference to FIGS.
[0069]
FIG. 4A shows the side structure of the device, and FIG. 4B shows the planar structure of the structure of the device. The liquid crystal optical device 10b has a structure 20c extending in the thickness direction of the liquid crystal layer 18. And a lattice-like object having an opening 24 formed in the extending direction. The structure 20c may be a single lattice formed over the entire liquid crystal layer 18, or may be an aggregate of a plurality of lattices. The structure 20c may be said to have a structure in which the surrounding walls are regularly arranged in the liquid crystal layer 18, in other words, as one mode of the surrounding walls that go around in parallel with the liquid crystal holding portion.
[0070]
Further, the liquid crystal optical element 10b may have a structure in which one end of the structure 20c is separated from the alignment film 16a, for example, as shown in FIG. 5, or a side surface of the structure 20c, as shown in FIG. Alternatively, a configuration may be adopted in which a slit-like opening 26 extending in the thickness direction of the liquid crystal layer 18 is formed. In the latter case, the opening interval of the openings 26 in the perimeter units (four sides forming one lattice in FIG. 6) constituting one virtual closed loop (frame-like lattice without the openings 26) of the structure 20c When the total extension distance (C1 + C2) of C1 and the opening interval C2 is set to be equal to or less than の of the total length of the circumference unit, the wettability between the liquid crystal molecules of the liquid crystal layer 18 and the side surface of the structure 20c. Is more reliably ensured, and the alignment state of the liquid crystal can be more effectively regulated.
[0071]
On the other hand, in the liquid crystal optical element 10c whose planar structure is shown in FIG. 7, the structure 20d extending in the thickness direction of the liquid crystal layer 18 has the shape and size of the opening 28 formed in the extending direction. Each of them is formed under appropriate conditions, in other words, is composed of an aggregate of irregularly shaped cylindrical objects. The respective structures 20d may be in a form fixed to each other, or may be in a form separated from each other and independent. The structure 20d may be said to be a liquid crystal layer 18, in other words, a plurality of sets of circling walls arranged as one mode of the circulating walls circling in parallel with the liquid crystal holding portion.
[0072]
As in the case of the lattice-shaped structure 20c described above, the structure 20d may have a configuration in which one end of the cylinder is separated from the alignment film 16a, for example. A configuration in which a slit-shaped opening extending in the thickness direction of the layer 18 may be formed.
[0073]
Next, a liquid crystal optical element according to a second example of the present embodiment will be described with reference to FIG.
[0074]
The liquid crystal optical element 30 according to the second example of the present embodiment has substantially the same structure as the transmissive liquid crystal optical element 10b of FIG. 4, but has a liquid crystal display function. Is different from
[0075]
In the liquid crystal optical element 30, the electrodes formed on the substrates 12a and 12b are pixel electrodes 32 and 34 formed corresponding to the pixels. In this case, when the liquid crystal optical element 30 is of a simple driving system, the intersections of a plurality of electrode bands arranged orthogonally to each other and spaced apart become the pixel electrodes 32 and 34. On the other hand, when the liquid crystal optical element 30 is of the active drive type, a plurality of pixel electrodes 32 connected to the transistor are provided for each pixel, and the pixel electrode 34 is provided as one common electrode (see FIG. 10). .
[0076]
In the liquid crystal optical element 30, each side of the structure 36 formed of a lattice-like material is disposed in a gap between adjacent pixel electrodes 32. In other words, each side of the structure 36 is formed so as to surround the pixel.
[0077]
The liquid crystal optical element 30 configured as described above can display an image by driving the liquid crystal for each pixel. At this time, it is possible to obtain a smooth moving image without an afterimage as compared with a device using a conventional twisted nematic liquid crystal.
[0078]
In addition, in the liquid crystal optical element 30, since the openings of the pixels indicated by the arrow A1 in FIG. 8B are not covered with the structures 36, it is possible to obtain a high-luminance image display without reducing the aperture ratio. Can be.
[0079]
Further, as shown in FIG. 9, the liquid crystal optical element 30 is formed so that the liquid crystal portions located on both sides of the structure 36 can communicate with each other. , A stable and reliable high-speed response operation can be obtained.
[0080]
Next, a first modification of the liquid crystal optical element 30 will be described with reference to FIG.
[0081]
The liquid crystal optical element 30a according to the first modification is a reflection type element of an active drive system.
[0082]
The liquid crystal optical element 30a differs from the liquid crystal optical element 30 in that the pixel electrode 38 on which the alignment film 16a is formed has a reflection mirror (not shown).
[0083]
In the liquid crystal optical element 30a, a transistor 40 for driving a pixel electrode 38 provided for each pixel is provided to be connected to each pixel electrode 38. The transistor 40 includes a source 40a, a drain 40b, and a gate 40c. Reference numeral 42 indicates a storage capacitor, and reference numeral 44 indicates a light shielding layer. A driver such as the transistor 40 is provided between the pixel electrode 38 and a substrate 46 made of a silicon material. Note that the pixel electrode 48, which is a common electrode, is formed of an ITO material, and the substrate 12b is formed of a glass material.
[0084]
The liquid crystal optical element 30a can obtain the same effect as the liquid crystal optical element 30.
[0085]
Here, in the liquid crystal optical elements 30 and 30a, as shown in FIGS. 11A and 11B, a structure 50 made of a grid-like material having a slit surrounds one pixel A1 with one grid. Alternatively, as shown in FIG. 11C, a structure 52 formed of a grid-like material having slits may be formed so as to surround, for example, four pixels A1 with one grid. . Note that the structures 50 and 52 may not have a slit.
[0086]
Next, a second modification of the liquid crystal optical element 30 will be described with reference to FIG.
[0087]
The liquid crystal optical element 30b of the second modified example has substantially the same structure as the liquid crystal optical element 30, but the structure 54 has a lattice structure 54a similar to the liquid crystal optical element 30 as a skeleton structure. The liquid crystal optical element 30 differs from the liquid crystal optical element 30 in that a surrounding wall 54b is formed on the pixel electrode 32, in other words, also in the pixel area.
[0088]
In the liquid crystal optical element 30b of the second modified example, since the probability of contact between the liquid crystal molecules of the liquid crystal layer 18 and the side surface of the structure 54 is large, the bend alignment can be easily obtained.
[0089]
The surrounding wall 54b of the structure 54 has a plurality of pixel electrodes 32 within a range occupying 60% or less of the total area of the plurality of pixel electrodes 32 in a plan view state (the state shown in FIG. 12B). When formed above, the aperture ratio of the pixel is not significantly affected.
[0090]
Next, a method for manufacturing a liquid crystal optical element according to a third example of the present embodiment will be described with reference to FIG.
[0091]
As described above, in the liquid crystal optical element of the present invention, each member such as the substrate, except for the structure, can be manufactured by a usual method using each of the above-described materials. Therefore, in the following description, a material used for the structure and a method for manufacturing the structure are described in detail.
[0092]
The structure of the liquid crystal optical element of the present invention does not limit the type of material as long as it has a certain wettability with liquid crystal, and can be manufactured using an appropriate organic material or an inorganic material. . The method for manufacturing the structure is not particularly limited, and an appropriate film formation method can be used.
[0093]
However, in order to exhibit the function and effect of the liquid crystal optical element of the present invention more appropriately, the liquid crystal optical element of the present invention is manufactured by the method of manufacturing a liquid crystal optical element according to the third example of the present embodiment described below. I do.
[0094]
In the method for manufacturing a liquid crystal optical element according to the third example of the present embodiment, an alignment film and an electrode are provided by applying a liquid mixture (mixture) of a liquid crystal material and a reaction-curable polymer material, respectively. It is arranged between two substrates. Then, the reaction-curable polymer material is polymerized, by locally irradiating the mixed solution using light or an electron beam that can be cured, in other words, by patterning and curing the reaction-curable polymer material, A structure is formed in the liquid crystal layer.
[0095]
As the reaction-curable polymer material, any one or both of a monomer and an oligomer can be used. It is more preferable that the monomer or the oligomer has liquid crystallinity, since the alignment of the liquid crystal can be freely controlled according to the alignment state of the liquid crystalline monomer or the like in the cured structure.
[0096]
The above-described monomer or oligomer can be appropriately selected from any of acrylate, epoxy, epoxy acrylate, ester acrylate, and urethane acrylate materials, or a mixture thereof.
[0097]
When the viscosity of the reaction-curable polymer material is 300 (unit: cps) or less, the polymerization reaction can be performed at high speed, and the unreacted material does not remain in the liquid crystal. Can be formed, which is suitable for obtaining a structure having a desired structure.
[0098]
In addition, when a polymerization initiator (photopolymerization initiator) sensitive to the wavelength of the light source is added to the reaction-curable polymer material (more precisely, a mixed solution) and used, the manufacturing time of the structure can be reduced. .
[0099]
In addition, when a colorant composed of a dye or a pigment is added to a reaction-curable polymer material and used, the colorant acts as a light absorber when the liquid crystal optical element has an image display function. , And a high-contrast image display can be obtained.
[0100]
Further, as the reaction curable polymer material, either a main chain polymer mainly containing a liquid crystal material in a main chain, a side chain polymer mainly containing a liquid crystal material in a side chain, or a mixture thereof is used. be able to. For example, when the reaction-curable polymer material includes a liquid crystalline material such as a bifunctional acrylate material, a main chain structure mainly including the liquid crystalline material in the main chain can be obtained. When the curable polymer material includes a liquid crystalline material such as a monofunctional liquid crystalline monomer, a side-chain structure mainly including the liquid crystalline material in a side chain can be obtained. When the reaction-curable polymer material includes, for example, a mixed material of a monofunctional liquid crystalline monomer, a trifunctional monomer, and a trifunctional oligomer, a complex in which the main chain and side chain arrangement structures are intricate. A mold structure can be obtained.
[0101]
The mixing ratio of the liquid crystal material and the reaction-curable polymer material in the mixed liquid is preferably adjusted so as to satisfy the following formula.
[0102]
That is, the exposure area (S _P ), The total area of the liquid crystal layer including the exposure area (S _D ), Mass of the reactive curable polymer material to be applied (W _P ) And the mass of the applied liquid crystal material (W _LC ) Satisfy the following formula.
[0103]
(Formula) S _P / S _D ≧ 1.5W _P / (W _P + W _LC )
Here, when assuming that a surrounding wall having the same extension height as the thickness of the liquid crystal layer is assumed as a structure to be formed, the exposure area (S _P ) Is approximately proportional to the volume of the structure, while the total area (S _D ) Is substantially proportional to the total volume of the liquid crystal layer including the structure.
[0104]
Therefore, the above expression simply means that the mass of the structure when a structure having a predetermined volume is manufactured is adjusted to a predetermined value or less. In the formula, the coefficient of 1.5 is a value that takes into account the specific gravity of the liquid crystal material and the reaction-curable polymer material and the degree of freedom of the mass ratio at the time of manufacturing the structure. It can be carried out.
[0105]
By adjusting the relationship between the liquid crystal material and the reaction-curable polymer material so as to satisfy the above equation, the residual uncured reaction-curable polymer material that may remain when the reaction-curable polymer material is cured The amount can be minimized.
[0106]
In addition, when a material having a contact angle with liquid crystal molecules constituting a liquid crystal layer of 50 ° or less is selected and used as a reaction curable polymer material in a state where a structure is formed, the surface of the structure is Since the liquid crystal is easily aligned, the bend alignment state of the liquid crystal can be more easily obtained.
[0107]
The light source that emits light or an electron beam is a high-intensity lamp such as a high-pressure mercury lamp, a xenon lamp, or a metal halide lamp, or an incandescent lamp such as a halogen lamp, which has a wavelength component that can cure the reaction-curable polymer material. A light bulb or a laser (laser light source) can be suitably used.
[0108]
Then, in order to obtain a structure having a predetermined structure, it is preferable that the light (light flux) of these light sources is uniformly pattern-exposed through a photomask (see FIG. 13), or the light (light rays) of the light source is also used. Is finely scanned to perform drawing exposure.
[0109]
Thus, a structure having a desired structure can be easily obtained.
[0110]
At this time, after the exposure, a uniform luminous flux is applied to the entire surface of the liquid crystal optical element to uniformly expose the entire liquid crystal layer including the structure, thereby curing the unreacted reaction-curable polymer material. Is preferred.
[0111]
In addition, the liquid crystal layer can be composed of the nematic phase by polymerizing and curing the reaction-curable polymer material in the temperature environment of the nematic phase of the liquid crystal material, and a π cell capable of high-speed operation can be easily obtained. be able to.
[0112]
When an electric field is applied to the liquid mixture of the liquid crystal material and the reaction-curable polymer material in the step of forming a structure by irradiating light or the like, the alignment controlling force of the structure is applied to the liquid crystal, and the electric field controls the liquid crystal alignment. It can be performed and is more preferable.
[0113]
For example, when a coating film is formed using a liquid mixture of a reaction curable polymer material containing a liquid crystal monomer and a liquid crystal material composed of a nematic liquid crystal, and an electric field is applied to the coating film, the liquid crystal monomer changes in accordance with the electric field strength. Thus, the liquid crystal is cured in an alignment state similar to the spatial alignment state of the nematic liquid crystal. Thereby, a guest-host effect can be obtained.
[0114]
Further, for example, as shown in FIG. 13, a power supply 60 is used to form an electrode 14a by using a mixed liquid of a reactive curable polymer material having a positive dielectric constant and containing a liquid crystal monomer 56 and a liquid crystal material composed of a nematic liquid crystal 58. , 14b under a high electric field applied through the photomask 62 to obtain a structure 63 in which the liquid crystal monomers 56 are arranged in the thickness direction of the liquid crystal layer 18. . Thereby, a guest-host effect can be obtained.
[0115]
The relationship between the timing of applying an electric field to the liquid mixture and the time of irradiating the liquid mixture with light or the like can be various combinations as described below.
[0116]
For example, after applying an electric field in advance, the reaction-curable polymer material can be cured (patterning curing treatment) in a state where the electric field is released. In this case, the liquid crystal (liquid crystal molecules) can be stabilized in an arbitrary alignment state in a transition state that changes between when the electric field is turned on and when it is turned off. Further, an electric field may be applied at the same time as the reaction-curable polymer material is cured. In this case, the alignment state of the liquid crystal can be accurately controlled according to the electric field strength. Further, an electric field may be continuously applied before the reaction-curable polymer material is cured until the curing is completed. In this case, the alignment state of the liquid crystal can be rapidly changed and stabilized. For example, if the present invention is applied to a parallel alignment cell, the liquid crystal can be previously transferred from the splay alignment to the bend alignment before curing, and the degree of stabilization in the bend alignment state according to the electric field intensity during the curing can be reduced. Can be controlled.
[0117]
When an electric field is applied continuously before the reaction-curable polymer material is cured until the curing is completed, the strength of the electric field applied before the curing is smaller than the strength of the electric field applied during the curing. It is more preferable that the strength is adjusted to be high. For example, the strength of the former electric field is set to 1 (unit: V / μm) or more, and the strength of the latter electric field is set to 0.5 (unit: V / μm) or less. .
[0118]
Further, if necessary, it is more preferable that the entire liquid crystal layer is uniformly exposed after curing. In this case, it is more preferable to apply an electric field having an intensity of 1 (unit: V / μm) or more. Thereby, the uncured (unreacted) liquid crystalline monomer or the like of the reactive curable polymer material remaining in the liquid crystal layer can be surely cured.
[0119]
【Example】
The present invention will be further described with reference to examples. The present invention is not limited to the embodiments described below.
(First embodiment)
The transmission type liquid crystal optical element shown in FIG. 4 was manufactured as follows.
[0120]
A pair of glass substrates with a transparent electrode was prepared. At this time, the glass substrate on one side has a height of 8 μm, the thickness of the four surrounding walls forming the grid (the width of the surrounding wall when viewed in plan) is about 20 μm, and the length of each side of one grid. In other words, in other words, a structure made of a lattice-like material having a lattice spacing of about 500 μm has been formed. A small hole having a diameter of about 2 μm was formed through the peripheral wall of the structure.
[0121]
After each of the pair of glass substrates was coated with a polyimide film, a rubbing treatment was performed to arrange a pair of alignment films made of the polyimide film in a parallel alignment state. The alignment film used a pretilt angle of about 7 °. The cell gap was controlled by arranging a spherical plastic spacer having a diameter of about 8 μm on the periphery of the glass substrate, and the distance between the glass substrates when a pair of glass substrates was bonded was adjusted uniformly.
[0122]
Next, a nematic liquid crystal was injected into the cell gap in a vacuum (low pressure equal to or lower than the atmospheric pressure) to produce a π cell. As the nematic liquid crystal, a material having a spreading elastic modulus and a bending elastic modulus of 14 pN and a viscosity of 30 cps was used.
[0123]
In the obtained liquid crystal optical element, in an initial state where no electric field was applied, a liquid crystal in a liquid crystal phase in which bend alignment was substantially stabilized was obtained. That is, in almost all of the manufactured liquid crystal optical elements, the liquid crystal was in a bend alignment. The splay alignment state of the liquid crystal was observed for some liquid crystal optical elements, but when a voltage of 5 V was applied and held for about 10 s (sec), the bend alignment was stabilized, and the bend alignment was maintained even when the power was turned off. I was drunk. In this liquid crystal optical element, no reverse transition from the bend alignment to the splay alignment occurred even when one month or more had elapsed with the power supply turned off.
[0124]
As a result of measuring the response speed of the liquid crystal optical element, a high-speed operation with a rise time of 0.5 ms and a fall time of 2 ms was confirmed.
(Second embodiment)
The liquid crystal optical element according to the second embodiment, which has a structure in which one grid of a grid-like object having a slit formed therein surrounds four pixels and has an image display function as shown in FIG. It was manufactured in the same manner as in the first embodiment. The size of one pixel is 200 μm × 300 μm, and the thickness of the surrounding wall forming the lattice is 10 μm. It should be noted that the structure of the second embodiment does not have minute holes as in the first embodiment.
[0125]
When the liquid crystal was injected to form a liquid crystal layer, the liquid crystal could be injected uniformly through the slit of the structure.
[0126]
The obtained liquid crystal optical element had the same high-speed response characteristics as those of the first embodiment. In addition, even when no voltage was applied, stable bend alignment could be realized. Further, when an image was displayed by driving the liquid crystal for each pixel, a smooth moving image display without an afterimage was confirmed as compared with a device using a conventional twisted nematic liquid crystal.
(Third embodiment)
A liquid crystal optical element according to a third embodiment was manufactured by changing a pair of glass substrates of the liquid crystal optical element according to the first embodiment to a substrate made of a polycarbonate resin having a thickness of 100 μm.
[0127]
In the liquid crystal optical element of the third embodiment, a nematic liquid crystal was applied by a printing method to form a liquid crystal layer without forming minute holes as in the structure of the first embodiment. As a printing method, any of a flexographic method, letterpress (letterpress) printing, offset (flat plate) printing, and gravure (intaglio) printing could be applied.
[0128]
The obtained liquid crystal optical element had the same high-speed response characteristics as those of the first embodiment. Further, the liquid crystal optical element of the third embodiment showed a stable high-speed operation even if it was rolled up or rolled up and then expanded again.
(Fourth embodiment)
The liquid crystal optical element of the active drive system shown in FIG. 10 was manufactured by the same method as in the first embodiment. The reflection type liquid crystal optical element of the fourth embodiment is a high definition display element generally called LCOS (Liquid Crystal on Silicon).
[0129]
In the reflection type liquid crystal optical element of the fourth embodiment, the arrangement pitch of adjacent pixels was 10 μm, and the gap between pixels, in other words, the thickness of the surrounding wall of the structure was 0.5 μm. Also, since the element was of a reflection type, the cell gap and the height of the structure were adjusted to 4 μm, which were half those of the first embodiment. The number of pixels of the liquid crystal optical element is 1080 × 1980.
[0130]
The liquid crystal optical element of the fourth example was confirmed to have the same high-speed response characteristics and the stability of bend alignment as those of the first example. In particular, the response characteristics were better than those of the first example, with the rise time being 0.2 ms and the fall time being 0.9 ms.
[0131]
Further, when a full-color projector system was constructed using three liquid crystal optical elements of the fourth example, good moving image characteristics could be obtained. When an image display operation was performed by a field sequential method without using a color filter, in which color display was performed by sequentially switching the three primary colors of RGB in one field, a favorable color moving image display was confirmed.
(Fifth embodiment)
The liquid crystal optical element of the first example of the fifth embodiment was manufactured in which the liquid crystal layer of the liquid crystal optical element of the first embodiment was formed using ferroelectric liquid crystal instead of nematic liquid crystal. In addition, the pair of alignment films of the liquid crystal optical element of the first example was changed to parallel alignment and anti-parallel alignment.
[0132]
The obtained liquid crystal optical element of the first example was confirmed to operate at a high speed of 100 μs or less.
In addition, stable operation can be obtained even when a shock is applied to the liquid crystal optical element. Even after a temperature change of 10 to 70 ° C., the liquid crystal alignment is not disturbed at room temperature and stable operation can be performed. was gotten.
[0133]
Further, a liquid crystal optical element according to a second example of the fifth embodiment was manufactured in which the liquid crystal layer of the liquid crystal optical element according to the second embodiment was formed using ferroelectric picture-based liquid crystal instead of nematic liquid crystal.
With respect to the obtained liquid crystal optical element of the second example, the same characteristics as those of the liquid crystal optical element of the first example were confirmed. In addition, it was confirmed that the liquid crystal optical element of the second example was stable in the orientation of the liquid crystal even after being shocked by being bent or dropped.
(Sixth embodiment)
The liquid crystal optical element shown in FIG. 4 was manufactured as follows using the manufacturing method of the present invention.
[0134]
A pair of glass substrates with a transparent electrode was prepared, and after each of the glass substrates was coated with a polyimide film, rubbing treatment was performed, and a pair of alignment films made of the polyimide film were arranged in a parallel alignment state. The alignment film used a pretilt angle of about 7 °.
The cell gap was controlled by arranging a spherical plastic spacer having a diameter of about 8 μm on the periphery of the glass substrate, and the distance between the glass substrates when a pair of glass substrates was bonded was adjusted uniformly.
[0135]
Next, a mixed liquid composed of a reaction curable polymer material containing a nematic liquid crystal and a liquid crystalline monomer as main components was injected into the cell gap. As the nematic liquid crystal, a material having a spreading elastic modulus and a bending elastic modulus of 14 pN and a viscosity of 30 cps was used. As the liquid crystal monomer, a monofunctional acrylic material having a viscosity of 40 cps was used.
[0136]
Ultraviolet rays having a wavelength of 365 nm were locally irradiated to the liquid crystal cell through a photomask in which the length of one side of each grid was 500 μm and the width of the grid (wall) was 20 μm, thereby performing polymerization phase separation. As a result, as shown in FIG. 14A, the structure 64 corresponding to the shape of the photomask was separated from the liquid crystal layer 18 and formed independently.
[0137]
At this time, the compounding ratio of the nematic liquid crystal 58 and the reaction-curable polymer material is determined by the exposure area (S _P ), The total area of the liquid crystal layer including the exposure area (S _D ), Mass of the reactive curable polymer material to be applied (W _P ) And the mass of the applied liquid crystal material (W _LC ) Satisfy the following equation.
[0138]
(Formula) S _P / S _D ≧ 1.5W _P / (W _P + W _LC )
Specifically, the liquid crystal optical element was manufactured by variously adjusting the mass blending ratio of the reaction curable polymer material to all the materials so as to satisfy the above formula, from 1 to 11.5%. As a result, a beautiful lattice-like structure completely separated from the liquid crystal layer (liquid crystal) could be formed. In addition, as a reference example, when a liquid crystal optical element was manufactured by setting the mass mixing ratio of the reaction curable polymer material to all materials to 15% or more, a large amount of unreacted liquid crystal monomers remained in the liquid crystal layer. It was recognized that. As a result of further uniform exposure of the liquid crystal optical element, amorphous polymers were deposited in the liquid crystal layer.
[0139]
The obtained structure 64 of the liquid crystal optical element of the sixth embodiment was cured in a splay alignment state in which liquid crystal monomers 64a were uniformly arranged in parallel to the surfaces of the substrates 12a and 12b.
[0140]
When the liquid crystal optical element of the sixth embodiment was subjected to light modulation operation, the liquid crystal in the liquid crystal layer maintained a stable splay state when no voltage was applied, as shown in FIG. When a voltage of 3.5 V was applied from the power supply 66 and operated, as shown in FIG. 14B, it was confirmed that the transition to the bend orientation was easily made. When the device was operated by applying a pulse voltage of 5 V, a high-speed operation of 5 ms or less was confirmed, and it was found that the liquid crystal optical element was applicable to a bistable element.
(Seventh embodiment)
An element having basically the same structure as that of the liquid crystal optical element of the above-described sixth embodiment was produced as follows, with the manufacturing method partially changed from that of the sixth embodiment.
[0141]
Before irradiating light or the like to perform polymerization phase separation, a voltage was previously applied to the liquid crystal cell to transition the liquid crystal from the splay alignment to the bend alignment. The time required for the transfer greatly varies depending on the applied voltage, but was 1 second (s) or less when the voltage was 20 V and 60 seconds when the voltage was 5 V. The time required for the transition also depends on the pretilt angle of the alignment film. By changing the pretilt angle from 7 ° to 10 °, the transition was performed at a high speed in less than 10 seconds even at an applied voltage of 5V. On the other hand, when the pretilt angle was changed to 2 °, it took 120 seconds or more to complete the transition even at an applied voltage of 20V.
[0142]
Immediately after the bend transition, the applied voltage was lowered to near the transition voltage to make the voltage constant, and then the liquid crystal cell was locally irradiated with ultraviolet light having a wavelength of 365 nm through a lattice-like pho and a mask. In addition, it was previously found by experiments that the transition voltage of the liquid crystal cell was 4 V, 1.7 V, and 0.7 V when the pretilt angles were 2 °, 7 °, and 9 °.
[0143]
In each of the obtained liquid crystal optical elements of the seventh example, it was confirmed that the liquid crystalline monomer of the structure was cured in a bend alignment state.
[0144]
Also, when the light modulation operation of each liquid crystal optical element was measured, the alignment state of the liquid crystal was stable in a substantially bent state from the initial state. In some liquid crystal optical elements, a splay alignment state was observed in the initial state, but when the applied voltage of 5 V was maintained for about 10 seconds, the bend alignment was stabilized, and the bend state was maintained even after the voltage was released. Was. Further, in this liquid crystal optical element, no reverse transition from the bend alignment to the splay alignment occurred at all even when no voltage was applied for a long period of one month or more.
[0145]
When the response speed of each liquid crystal optical element was measured, a high-speed operation with a rise time of 0.5 ms and a fall time of 2 ms was confirmed, and it was found that the liquid crystal optical element was suitable for a moving image display element for television use.
[0146]
In the conventional π cell, the liquid crystal is in the splay alignment in the initial state where no voltage is applied, and it is necessary to apply a high voltage to transition the liquid crystal to the bend alignment. In the optical element, since a stable bend orientation is obtained in the initial state, a modulation operation from 0 V is possible.
[0147]
Further, in the liquid crystal optical element of the seventh embodiment, since the structure is formed surely spatially separated from the liquid crystal layer, the refractive index between the liquid crystal and the structure having high transmission characteristics is increased. High contrast can be obtained without scattering due to mismatch.
[0148]
When a thin film transistor is used as a transistor, if an unreacted liquid crystalline monomer remains in the liquid crystal layer, it is expected that a problem such as a reduction in voltage holding ratio will occur. As a result, a high voltage holding ratio of 95% or more was obtained, and it was confirmed that the device was sufficiently practical. At this time, the liquid crystal optical element which was further uniformly exposed after curing was able to increase the voltage holding ratio to 99% or more. The liquid crystal optical element having a voltage holding ratio of 99% or more did not show any deterioration in image display characteristics such as transmittance, contrast, and response speed.
(Eighth embodiment)
In the sixth and seventh embodiments, a liquid crystalline monomer was used as the main component of the reaction curable polymer material. However, in the eighth embodiment, the liquid crystalline monomer was replaced with a non-liquid crystalline monomer. A reaction-curable acrylic resin, which is a polymer material, was used. The basic manufacturing method of the liquid crystal optical element of the eighth embodiment is the same as that of the sixth embodiment and the seventh embodiment.
[0149]
As a first example of the eighth embodiment, only the curing is performed without applying an electric field to the reaction curable polymer material to control the orientation when fabricating the device as in the sixth and seventh embodiments. Was done.
[0150]
As the reaction-curable acrylic resin, NOA72 manufactured by Norland Co., or a low-viscosity (about 175 cps) product of a bifunctional monomer KAYARAD R-684 (KAYARAD is a registered trademark) manufactured by Nippon Kayaku was used.
[0151]
The obtained liquid crystal optical element of the first example was in the splay alignment state in the initial state, but immediately transitioned to the bend alignment when a voltage of 5 V was applied, and thereafter returned to the splay alignment state even when the voltage was released. I never did. This bend orientation did not shift even after repeated operation or even in the off state for a long period of one month.
[0152]
On the other hand, as a second example of the eighth embodiment, a reaction-curable acrylic resin is used as a main component of the reaction-curable polymer material as in the first example, and a device is manufactured in the same manner as in the sixth embodiment. Then, the reaction-curable polymer material was cured while controlling the orientation by applying an electric field.
[0153]
In the obtained liquid crystal optical element of the second example, the same liquid crystal alignment state and operation characteristics as those of the seventh example were obtained.
[0154]
Here, with respect to the liquid crystal optical element of the second example of the eighth embodiment, an element was manufactured by changing the viscosity of the reaction curable acrylic resin within the range of 40 to 2000 cps, and the influence of the viscosity was examined.
[0155]
As the reaction curable acrylic resin, NOA65 manufactured by Norland Co., Ltd., or KAYARAD R-167 manufactured by Nippon Kayaku Co., Ltd. was used.
[0156]
When the viscosity was 250 cps or less, the obtained liquid crystal optical element had a uniform and beautiful lattice-like structure. On the other hand, when the viscosity is 300 cps or more, the obtained liquid crystal optical element has a structure with a non-uniform lattice shape, and the monomer of the reaction curable acrylic resin remains in the liquid crystal layer. Was observed. In this case, the higher the viscosity was, the more remarkable the phenomenon was.
[0157]
Further, the liquid crystal optical element of the second example is reacted by changing the temperature of the liquid crystal cell within the range of 10 to 90 ° C. during the polymerization phase separation, instead of using the above-described reaction-curable acrylic resin having a different viscosity. The device was manufactured by changing the viscosity of the curable acrylic resin, and evaluated.
[0158]
As for the obtained liquid crystal optical element, a clearer lattice-like structure was obtained as the liquid crystal cell was manufactured at a higher temperature. However, when the temperature of the liquid crystal cell was set to 80 ° C. or higher where the liquid mixture of the liquid crystal and the reactive curable acrylic resin monomer became an isotropic phase, a non-uniform structure having a lattice shape was obtained. In the case where the liquid crystal is cured by controlling the alignment of the liquid crystal by applying an electric field, for example, when a voltage of 2 V is applied in a nematic phase at 65 ° C. to cure the reaction-curable acrylic resin, a uniform structure is obtained. And a stable liquid crystal alignment was obtained. Further, even when a reaction-curable acrylic resin having a high viscosity is used, there is a tendency that the lattice shape of the structure is made uniform by increasing the temperature of the liquid crystal cell. For example, a reaction-curable acrylic resin having a viscosity of 1000 cps is used. A uniform lattice-like structure was obtained for a liquid crystal optical element produced using a resin and the temperature of the liquid crystal cell at 60 ° C.
(Ninth embodiment)
An element having basically the same structure as the liquid crystal optical element of the above-described seventh embodiment was manufactured as follows, with the manufacturing method partially changed from that of the seventh embodiment.
[0159]
In the seventh embodiment, a glass material is used for each of the pair of substrates. In the ninth embodiment, one substrate is formed of a silicon material. In other words, the liquid crystal optical element of the ninth embodiment is obtained by manufacturing an element having basically the same structure as the reflective element of the fourth embodiment by one embodiment of the manufacturing method of the present invention.
[0160]
Ultraviolet irradiation was performed from the glass substrate side. At this time, the photomask to be used was irradiated with light so as to precisely match the pixel structure of the silicon substrate by the aligner, thereby forming the same structure as the pixel pitch and the pixel interval of the silicon substrate. At the time of ultraviolet irradiation, a mask image was formed between the photomask and the liquid crystal cell using a projection lens, whereby a uniform lattice-shaped structure without blurring of the mask shape could be formed.
On the other hand, even when the laser drawing method of irradiating the beam of the He-Cd line-of-sight laser was used, it was possible to form a uniform lattice-shaped structure without blurring of the mask shape.
[0161]
The obtained liquid crystal optical element of the ninth embodiment had the same characteristics as those of the liquid crystal optical elements of the fourth and seventh embodiments.
[0162]
【The invention's effect】
According to the liquid crystal optical element of the present invention, the liquid crystal layer holding portion includes a pair of substrates and a pair of electrodes respectively disposed on opposite surfaces of the pair of substrates and subjected to surface alignment treatment. And a liquid crystal optical element including a liquid crystal layer disposed between the liquid crystal layer holding portions, wherein the liquid crystal layer includes a structure extending in the thickness direction of the liquid crystal layer, and the side surface of the structure is flat or extended. A liquid crystal optical element having a high-speed response is obtained because the liquid crystal optical element is formed in a curved shape curved in a direction perpendicular to the exit direction and at least one end in the extension direction is fixed to the liquid crystal holding portion. be able to.
[0163]
Further, according to the liquid crystal optical element of the present invention, since the liquid crystal optical element further includes a phase compensator, an element having high contrast and a wide viewing angle can be obtained.
[0164]
Further, according to the liquid crystal optical element of the present invention, the pair of electrodes is a pixel electrode to which a voltage is applied to each pixel, and the structure is formed in a gap between adjacent pixel electrodes in a plan view state. Since it is provided, it is possible to obtain a smooth moving image with no afterimage as compared with a device using a conventional twisted nematic liquid crystal.
[0165]
Further, according to the method for manufacturing a liquid crystal optical element according to the present invention, the method for manufacturing a liquid crystal optical element described above, wherein a liquid crystal material and a reaction curable polymer material are provided on one side of the liquid crystal layer holding portion. And a step of forming a structure comprising a cured product of the reaction-curable polymer material by patterning and curing the reaction-curable polymer material. Can be easily obtained.
[0166]
According to the method of manufacturing a liquid crystal optical element of the present invention, in the step of forming the structure, a material containing a liquid crystal material is used as the reactive curable polymer material, and the material is preliminarily or before patterning and curing. Since an electric field is applied between the pair of electrodes at the time of the curing treatment, or both before the patterning curing treatment and at the time of the patterning curing treatment, the alignment of the liquid crystal can be more appropriately controlled.
[Brief description of the drawings]
FIG. 1 is a diagram showing a schematic configuration of a conventional liquid crystal optical element.
FIG. 2 is a diagram illustrating a schematic configuration of a liquid crystal optical element according to a first example of the present embodiment.
FIG. 3 is a diagram showing a schematic configuration of a modified example of the liquid crystal optical element of FIG. 2;
4A and 4B are diagrams showing a schematic configuration of a modified example of the structure of the liquid crystal optical element of FIG. 2, wherein FIG. 4A is a side view of the liquid crystal optical element, and FIG. Are respectively shown.
5 is a diagram showing a schematic side structure of a modification of the structure of the liquid crystal optical element shown in FIG. 2 which is different from that shown in FIG. 4;
6 is a diagram showing a schematic side structure of a modification of the structure of the liquid crystal optical element in FIG. 2 which is different from FIGS. 4 and 5;
7 is a diagram showing a schematic plan structure of a modification of the structure of the liquid crystal optical element of FIG. 2 which is different from FIGS. 4 to 6;
8A and 8B are diagrams illustrating a schematic configuration of a liquid crystal optical element according to a second example of the present embodiment, wherein FIG. 8A illustrates a side structure of the liquid crystal optical element, and FIG. 8B illustrates a structure of the liquid crystal optical element. The plane structures are shown respectively.
9 is a diagram illustrating a schematic side structure of one embodiment of the structure of the liquid crystal optical element in FIG. 8;
FIG. 10 is a view showing a schematic side structure of a first modification of the liquid crystal optical element of FIG. 8;
11 is a diagram showing a schematic plan structure of three modified examples of the structure of the liquid crystal optical element in FIG. 10;
12A and 12B are diagrams showing a schematic configuration of a second modification of the liquid crystal optical element of FIG. 8, wherein FIG. 12A is a side view of the liquid crystal optical element, and FIG. 12B is a plan view of a structure of the liquid crystal optical element. Are respectively shown.
13A and 13B are diagrams for explaining a method for manufacturing a liquid crystal optical element according to a third example of the present embodiment, wherein FIG. 13A illustrates a schematic side structure of a liquid crystal optical element material during irradiation with ultraviolet light, and FIG. () Shows the schematic side structure of the obtained liquid crystal optical element.
14A and 14B are diagrams for explaining an operation state of the liquid crystal optical element according to the sixth embodiment. FIG. 14A is a schematic side view of a liquid crystal optical element material in an initial state where no voltage is applied, and FIG. Indicates a schematic side structure of the liquid crystal optical element during voltage application.
[Explanation of symbols]
10, 10a, 10b, 30, 30a, 30b Liquid crystal optical element
12a, 12b, 46 substrates
14a, 14b, 14c electrodes
16a, 16b alignment film
18 Liquid crystal layer
18, alignment film
20a, 20b, 20c, 20d, 36, 50, 52, 54, 63, 64 structures
32, 34, 38, 48 pixel electrodes
40 transistors
54a lattice structure
54b orbiting wall
56, 64a Liquid crystalline monomer
58 Nematic LCD
62 Photomask

Claims (33)

A liquid crystal layer holding portion having a pair of substrates and a pair of electrodes respectively disposed on opposite sides of the pair of substrates and subjected to a surface alignment treatment, between the liquid crystal layer holding portions; A liquid crystal optical element comprising:
The liquid crystal layer includes a structure extending in a thickness direction of the liquid crystal layer,
The structure has a side surface formed in a flat shape or a curved shape curved in a direction orthogonal to the extending direction, and at least one end in the extending direction is fixed to the liquid crystal holding portion. A liquid crystal optical element characterized by the above-mentioned. The liquid crystal optical element according to claim 1, wherein the structure has a communication permitting structure that allows liquid crystal portions located on both sides to communicate with each other via the structure. 2. The liquid crystal optical element according to claim 1, wherein the structural body is provided with one end in an extending direction separated from the liquid crystal holding unit. 3. The liquid crystal optical element according to claim 1, wherein the structure is configured by a plurality of cylindrical objects. The liquid crystal optical element according to any one of claims 1 to 3, wherein the structure is formed of one or more lattice-like objects having openings in an extending direction. The liquid crystal optical element according to any one of claims 1 to 3, wherein the structure comprises one or two or more circling walls that circulate in parallel with the liquid crystal holding unit. The liquid crystal optical element according to any one of claims 1 to 6, wherein the structure has a slit-shaped opening formed on a side surface extending in a direction in which the structure extends. In a circling side unit that circulates in parallel with the liquid crystal holding unit to form one virtual closed loop of the structure, the total extension distance of the opening intervals of the slit-shaped openings is 以下 or less of the total length of the circling side unit. The liquid crystal optical element according to claim 7, wherein the liquid crystal optical element is formed to have a length of: The liquid crystal according to any one of claims 1 to 8, wherein the liquid crystal layer is formed of one or more liquid crystal materials selected from the group consisting of a nematic liquid crystal, a cholesteric liquid crystal, and a smectic liquid crystal. Optical element. 10. The liquid crystal optical element according to claim 9, wherein a ratio of a bending elastic constant K33 to a spreading elastic constant K11 of the liquid crystal material is 1.7 or less. 11. The liquid crystal optical element according to claim 9, wherein the spread elastic constant K11 of the liquid crystal material is 15 (unit: pN) or less. At least one of the pair of substrates is made of a polycarbonate resin, a polyester resin, a polyacrylate resin, a polyethylene terephthalate resin, a polyether sulfone resin, an epoxy resin, an amorphous polyolefin resin, an acrylic ultraviolet curing resin, glass and silicon. The liquid crystal optical element according to any one of claims 1 to 8, wherein the liquid crystal optical element is formed of a material selected from a group. The liquid crystal optical element according to any one of claims 1 to 8, wherein the pair of alignment films are aligned in parallel by the surface alignment treatment. The liquid crystal optical element according to claim 1, further comprising a phase compensator. The pair of electrodes is a pixel electrode to which a voltage is applied for each pixel,
The liquid crystal optical element according to claim 1, wherein the structure is provided in a gap between adjacent pixel electrodes in a plan view. The pair of electrodes is a pixel electrode to which a voltage is applied for each pixel,
2. The structure according to claim 1, wherein the structure is disposed on one or more of the pixel electrodes within a range occupying 60% or less of the total area of the pixel electrodes in a plan view. 15. The liquid crystal optical element according to any one of items 14 to 14. It is a manufacturing method of the liquid crystal optical element according to any one of claims 1 to 16,
A step of applying a mixture comprising the liquid crystal material and the reaction-curable polymer material to any one side of the liquid crystal layer holding portion,
Patterning and curing said reactive curable polymer material to form said structure comprising a cured product of said reactive curable polymer material. 18. The method according to claim 17, wherein in the step of forming the structure, the liquid crystal material is cured under a temperature environment of a nematic phase. 19. The method according to claim 17, wherein the reactive curable polymer material is one or both of a monomer and an oligomer. 20. The liquid crystal optical element according to claim 19, wherein the monomer or oligomer is one or more materials selected from the group consisting of acrylate, epoxy, epoxy acrylate, ester acrylate, and urethane acrylate. Manufacturing method. The method according to any one of claims 17 to 20, wherein the viscosity of the reactive curable polymer material is 300 (unit: cps) or less. 22. The method according to claim 17, wherein a polymerization initiator is added to the mixture in the applying step. 23. The method for manufacturing a liquid crystal optical element according to claim 17, wherein a colorant comprising a dye is added to the mixture in the applying step. The reaction-curable polymer material is a main chain polymer mainly containing a liquid crystal material in a main chain or a side chain polymer mainly containing a liquid crystal material in a side chain. 24. The method for producing a liquid crystal optical element according to any one of 17 to 23. In the step of forming the structure, a material containing a liquid crystalline material is used as the reactive curable polymer material, and is used before patterning and curing, or during patterning and curing, or before patterning and curing, and patterning. 25. The method for manufacturing a liquid crystal optical element according to claim 17, wherein an electric field is applied between the pair of electrodes at both times during the curing process. When an electric field is applied between the pair of electrodes before and after the patterning and curing treatment, the intensity of the electric field applied before the patterning and curing treatment is applied during the patterning and curing treatment. 26. The method for manufacturing a liquid crystal optical element according to claim 25, wherein the intensity of the applied electric field is higher. The intensity of the electric field applied before the patterning and curing treatment is 1 (unit: V / μm) or more, and the intensity of the electric field applied during the patterning and curing treatment is 0.5 (unit: V / μm) or less. The method for manufacturing a liquid crystal optical element according to claim 26, wherein: 28. The pattern forming and curing process according to claim 17, wherein, in the step of forming the structure, pattern light exposure is performed by using light from a light source through a photomask, or drawing exposure is performed by finely scanning the light from the light source. A method for producing the liquid crystal optical element according to any one of the preceding claims. 29. The method according to claim 28, wherein the light source is a high-pressure mercury lamp, a xenon lamp, a metal halide lamp, a halogen lamp, or a laser. 30. The method according to claim 28, further comprising uniformly exposing the entire liquid crystal layer including the structure after performing the pattern exposure or the drawing exposure. 31. The liquid crystal optical element according to claim 30, wherein, when uniformly exposing the entire liquid crystal layer, an electric field having an intensity of 1 (unit: V / [mu] m) or more is applied between the pair of electrodes. Manufacturing method. The exposure area (S _P ) for performing the pattern exposure or the drawing exposure, the total area (S _D ) of the liquid crystal layer including the exposure area, the mass (W _P ) of the reactive curable polymer material to be applied, and The method for producing a liquid crystal optical element according to any one of claims 28 to 31, wherein the mass (W _LC ) of the liquid crystal material to be applied is adjusted so as to satisfy the following relationship. .
_{(Formula) S P / S D ≧ 1.5W} P / (W P + W LC) 18. The reaction-curable polymer material is formed of a material having a contact angle with liquid crystal molecules constituting the liquid crystal layer of 50 ° or less when the structure is formed. 33. The method for manufacturing a liquid crystal optical element according to any one of Items 32 to 32.

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