JP7379262B2 - Liquid crystal alignment member for spatial light phase modulation, spatial light modulation element, and stereoscopic display device - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies March 29, 2019 Website URL: https://onlinelibrary. wiley. Published in JSID Online academic journal Early View published at com/toc/19383657/0/0

The present disclosure relates to a liquid crystal alignment member for spatial light phase modulation, a spatial light modulation element, and a stereoscopic display device.

Three-dimensional displays are expected to be applied not only to broadcasting and communications fields such as television broadcasting and videophones, but also to various fields including medicine, manufacturing, and education. In recent years, with the development of augmented reality (AR) technology and virtual reality (VR) technology, 3D displays that display 3D images and virtual spaces in 3D have been proposed. Among these, holographic displays are expected to be put into practical use as next-generation 3D displays because they enable natural 3D display that satisfies all physiological factors for 3D viewing. A holographic display is a display that modulates highly coherent light such as a laser light source, reproduces the wavefront of an object's light, and displays a three-dimensional image. The light from the light source is modulated by a light modulation element displaying a hologram, and the wavefront of the object's light is reproduced by interference that occurs during the propagation of the light. As modulation methods for light modulation elements, there are an amplitude method that reproduces a two-dimensional amplitude distribution of light, and a phase method (phase modulation element) that reproduces a phase distribution of light. Among these, the phase method has higher light utilization efficiency than the former, and has the advantage of being able to suppress the first-order diffracted light that interferes with the observation of reconstructed images, so it is considered a useful method for practical application. It is being

LCOS-SLM (Liquid Crystal on Silicon-Spatial Light Modulator) is a spatial optical phase modulator that uses liquid crystal.It uses a glass substrate with a transparent common electrode and a drive electrode that is arranged on a silicon backplane and also serves as a reflector to generate a liquid crystal. It is a reflective optical device with a sandwiched structure. A thin polymer film called an alignment film is coated on the interface between the liquid crystal and the substrate, and the liquid crystal molecules receive an alignment control force from the alignment film, which causes the long axis direction of the molecules to be fixed in one direction within the plane, and at the same time The axis is constrained to be parallel to the substrate. Therefore, when no electric field is applied, the liquid crystal is aligned horizontally to the substrate. At this time, when linearly polarized light vibrating parallel to the long axis direction of the liquid crystal molecules is incident, the refractive index perceived by the incident light becomes high. On the other hand, when an electric field is applied, the liquid crystal molecules rotate due to dielectric anisotropy so that the long axis becomes parallel to the direction of the electric lines of force, so the refractive index felt by the incident linearly polarized light is low. becomes. As a result, there is a difference in phase between the light that reflects the pixels in the ON state and the light that reflects the pixels in the OFF state, so it is possible to modulate the two-dimensional distribution of the phase by applying an electric field at each pixel. It is possible.

Y. Isomae, Y. Shibata, T. Ishinabe, and H. Fujikake, “Design of 1-maikurom-pitch liquid crystal spatial light modulators having dielectric shield wall structure for holographic display with wide field of view,” Opt. Rev. , vol. 24, no. 2, pp. 165-176, April. 2017. DOI: 10.1007/s10043-017-0316-0

Y. Isomae et al. , Experimental study of 1-μm-pitch light modulation of a liquid crystal separated by dielectric shield walls formed by nanoimprint technology for electronic holographic displays, Opt. Eng. 57(6), 061624 (2018).

Since a holographic display reproduces object light through light interference, the angular range (viewing zone angle) in which a reproduced image can be observed depends on the maximum diffraction angle determined by the pixel pitch of the spatial light phase modulation element.

The present inventors investigated the pixel pitch required to realize a practical holographic display. Specifically, assume a viewing environment in which a mobile terminal such as a tablet is placed on a tabletop, and reproduce an image 20 cm on a side at a distance of 50 cm. In this case, a viewing angle of 30° is theoretically required. In order to realize a viewing angle of 30°, calculation results have been obtained that the pixel pitch required for the phase modulation element is approximately 1 μm.

However, the minimum pixel pitch of currently realized phase modulation elements is 3.74 μm, and if the wavelength of light is 550 nm, the viewing angle is 8.4°. From the above, in order to realize a practical holographic display, it is necessary to narrow the pitch of the pixels of the spatial light phase modulation element.

The present inventors further performed a simulation of the liquid crystal alignment direction assuming a pixel pitch of 1 μm. The results are shown in FIG. Figure 7(a) shows the equipotential line distribution and liquid crystal alignment distribution in a state where pixels in the ON state (5V) and pixels in the OFF state (0V) are arranged alternately, and the solid lines in the figure are equal in 0.5V steps. It shows potential lines. Reference numeral 71 indicates a liquid crystal alignment direction, 72 a common electrode (0V), and 73 a pixel electrode. This result shows that the electric field leaks from the ON-state pixel to the OFF-state pixel. Furthermore, when paying attention to the orientation distribution of the liquid crystal, it can be seen that some of the liquid crystals in the pixels in the OFF state rotated. However, when focusing on the equipotential line distribution within a pixel in the OFF state, the electric field leaking out in the lateral direction is significant at the bottom of the liquid crystal layer, but the strength of the leaking electric field at the top of the liquid crystal layer causes the liquid crystal to rotate. is insufficient. This suggests that not only the leakage of the electric field but also the elastic force of liquid crystal alignment is propagated to the liquid crystal of the pixel in the OFF state. In order to clarify the effect of the elastic force of liquid crystal alignment on alignment change, Figure 7(b) shows the simulation results when vertically aligned liquid crystals are arranged assuming pixels in the ON state without applying an electric field. Ta. Even in a state where no electric field was applied, the liquid crystal of the pixel in the OFF state rotated only due to the propagation of the elastic force of liquid crystal alignment. From this, it has been found that in minute pixels with a pitch of about 1 μm, it becomes difficult to drive each pixel independently due to leakage of the electric field and propagation of the elastic force of liquid crystal alignment, resulting in a decrease in contrast.

Furthermore, according to simulations based on continuous elastic body theory, it has become clear that when the pixel pitch is 3 μm or less, the electric field when driving the pixel electrode propagates to the top of adjacent pixels, causing some liquid crystals to rotate. (See Non-Patent Document 1).

Furthermore, from this background, the present inventors have proposed a dielectric shield wall structure as a pixel structure (Non-Patent Document 2). A dielectric shield wall structure is one in which a dielectric wall is formed between pixels. In FIG. 8, a dielectric shield wall structure 82 is formed between adjacent pixel regions in a comb-like electrode 81. In FIG. 83 is a transparent substrate, 84 is an alignment film, 85 is a common electrode, and 86 is a glass substrate.

Here, in a liquid crystal device, it is necessary to form an alignment film on both the pixel electrode side and the counter electrode (common electrode) side, but after forming a dielectric shield wall structure with a high aspect structure as in the above technology, It has been found that it is difficult to form an alignment film on the pixel electrode side. For example, when using the rubbing method or photo-alignment method that is mainstream in the manufacturing process of LCD flat panel displays, there is a problem in that it is difficult to apply alignment film material onto a substrate on which a high aspect structure is formed. . Therefore, there is a problem in that it is difficult to control the orientation of the liquid crystal, and it is difficult to align the orientation of the liquid crystal. Further, although organic materials such as polyimide are usually used for liquid crystal alignment films, there is a problem in that light resistance becomes an issue when irradiating LCOS with high-intensity light.

The present disclosure has been made in view of the above-mentioned problems, and provides a spatial light phase modulation element that can easily control the orientation of liquid crystal and can obtain a spatial light modulation element with a pitch of pixel electrodes of 3 μm or less. The main purpose is to provide a liquid crystal alignment member for modulation.

The present disclosure provides a base portion including a silicon substrate, pixel electrodes provided on the surface of the silicon substrate and arranged in a matrix with a period of 3 μm or less, and arranged on the base portion, a lattice-like wall structure made of a dielectric material, in which a plurality of linear protrusions are combined; and a plurality of lattice-like wall structures on the base section, separated from each other by the lattice-like wall structure, for filling with liquid crystal. The lattice-like wall structure is disposed at least between pixel regions in which the adjacent pixel electrodes are formed, and the liquid crystal filling microspace is arranged in the plane of the base portion. A liquid crystal alignment member for spatial light phase modulation is provided, which is characterized by having shape anisotropy in mutually orthogonal directions.

With the liquid crystal alignment member for spatial light phase modulation of the present disclosure, even when the pixel pitch is as narrow as 3 μm or less when filled with liquid crystal and used as a light modulation element, electric field leakage from adjacent pixels and liquid crystal elastic force may occur. can block the spread of At the same time, one or more liquid crystal filling micro spaces corresponding to each of the pixel electrodes having a narrow pixel pitch of 3 μm or less have shape anisotropy in mutually orthogonal directions in the base plane. Since the structure itself has a liquid crystal alignment function, it is possible to align the liquid crystals.

In the present disclosure, the first axis of the pixel electrodes arranged in a matrix is set in a direction that coincides with the matrix direction, and the first axis is perpendicular to the first axis in a plane parallel to the base portion. When the second axis is taken as A and the space width in the first axis direction in the liquid crystal filling microspace is A and the space width in the second axis direction is B, A is 3 μm or less, and A It is preferable that B be a smaller value than B. If each space width has such a value, it becomes possible to provide a sufficient liquid crystal alignment function as a liquid crystal alignment member, and it is possible to obtain a sufficient phase modulation range as a spatial light modulation element.

Further, in the present disclosure, it is preferable that the lattice-like wall structure includes a wall portion that partitions the adjacent pixel regions, and a partition portion that partitions each of the pixel regions into two or more.

With a lattice-like wall structure composed of walls and partitions in this way, it is easy to make the fine space for liquid crystal filling have shape anisotropy in directions orthogonal to each other in the plane of the base. It is preferable because it can be done.

Further, it is preferable that the thickness of the lattice-like wall structure is 50 nm or more and 400 nm or less.

With such a thickness, a sufficient fine space for filling the liquid crystal can be secured. Furthermore, when filled with liquid crystal to form a light modulation element, it is possible to reliably block electric field leakage from adjacent pixels and propagation of liquid crystal elastic force, and even when there is no alignment film on the base. Also, it becomes possible to align the alignment of liquid crystals.

Further, in this case, it is preferable that the lattice-like wall structure has a height of 500 nm to 3000 nm.

With such a height, when filling liquid crystal to form a light modulation element, it is possible to reliably block electric field leakage from adjacent pixels and propagation of liquid crystal elastic force. Even if there is no film, it is possible to align the alignment of liquid crystals.

In the present disclosure, the first axis of the pixel electrodes arranged in a matrix is aligned with the matrix direction, and the first axis is perpendicular to the first axis in a plane parallel to the base portion. When the second axis is taken as the second axis, and the space width in the first axis direction in the liquid crystal filling microspace is A, and the space width in the second axis direction is B, the ratio of B to A (B/ It is preferable that A) is 2 or more. Within this range, the shape anisotropy in the mutually orthogonal directions in the plane of the base is sufficient, so it is possible to reliably control the alignment of the liquid crystal by utilizing the elasticity of the liquid crystal to be filled. Become.

The present disclosure provides a reflective spatial light phase modulation element that controls the phase of the incident light and the reflected light while reflecting the incident light, the element including a transparent substrate and a common element disposed on one main surface of the transparent substrate. an electrode, the above-mentioned liquid crystal alignment member for spatial light phase modulation disposed on the main surface of the common electrode opposite to the transparent substrate, and the above-mentioned fine space for filling liquid crystal in the liquid crystal alignment member for spatial light phase modulation. A spatial light modulator is provided, characterized in that it has a liquid crystal layer filled with a liquid crystal layer.
In the present disclosure, for the purpose of further stabilizing the liquid crystal alignment function, an alignment film may be disposed between the common electrode and the above-described liquid crystal alignment member for spatial light phase modulation.

Further, the present disclosure provides a stereoscopic display device comprising the above-described spatial light modulation element and a driving means for driving the above-mentioned pixel electrode.

With the spatial light modulation element and stereoscopic display device of the present disclosure, even when the pitch of pixel electrodes is as narrow as 3 μm or less, it is possible to easily control the orientation of liquid crystal independently in each pixel. .

In the present disclosure, it is possible to easily control the orientation of liquid crystal independently in each pixel, and it is possible to obtain a spatial light modulation element in which the pitch of pixel electrodes is 3 μm or less. Further, the present disclosure can provide a spatial light modulation element and a stereoscopic display device useful for ultra-high definition projectors, holographic displays using optical diffraction, and the like.

It is a top view and a schematic sectional view showing an example of a liquid crystal alignment member for spatial light phase modulation of this indication. It is a top view and a schematic sectional view which show another example of the liquid crystal alignment member for spatial light phase modulation of this indication. It is a top view and a schematic sectional view which show another example of the liquid crystal alignment member for spatial light phase modulation of this indication. It is a top view and a schematic sectional view which show another example of the liquid crystal alignment member for spatial light phase modulation of this indication. It is a top view and a schematic sectional view which show another example of the liquid crystal alignment member for spatial light phase modulation of this indication. It is a top view and a schematic sectional view which show another example of the liquid crystal alignment member for spatial light phase modulation of this indication. It is a graph showing the results of a simulation of liquid crystal alignment direction when the pixel pitch is assumed to be 1 μm. (a) A schematic cross-sectional view of a phase modulation element provided with a dielectric shield wall structure, and (b) an SEM image of an alignment member provided with a dielectric shield wall structure. FIG. 2 is a top view and a schematic cross-sectional view showing a liquid crystal alignment member for spatial light phase modulation manufactured in Comparative Example 1. FIG. FIG. 1 is a schematic cross-sectional view showing an example of a spatial light phase modulation element of the present disclosure. It is a polarizing microscope observation result in Example and Comparative Example 1. 2 is a perspective view of a spatial light phase modulation element sample used in an example and calculation results of an average transmittance ratio. It is a calculation result of the ratio of the average transmittance ratio R in an Example. It is a calculation result of the ratio of the average transmittance ratio R in a reference example.

Embodiments of the present disclosure will be described below with reference to the drawings and the like. However, the present disclosure can be implemented in many different ways, and should not be construed as being limited to the contents of the embodiments exemplified below. In addition, in order to make the explanation more clear, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the embodiment, but this is just an example and does not limit the interpretation of the present disclosure. It's not something you do. In addition, in this specification and each figure, the same elements as those described above with respect to the previously shown figures are denoted by the same reference numerals, and detailed explanations may be omitted as appropriate. Further, for convenience of explanation, the words "upward" and "downward" may be used in the explanation, but the up and down directions may be reversed.

In addition, in this specification, when a certain structure such as a certain member or a certain area is "above (or below)" another structure such as another member or another area, there is no particular limitation. As far as This also includes cases where components of the system are included.

As a result of intensive studies to solve the above problems, the present inventors have discovered that at least the adjacent pixel electrodes form a lattice-like wall structure in which a plurality of linear protrusions are combined and made of a dielectric material. By placing it between the pixel regions, it is possible to suppress the leakage of the electric field, and by spatially dividing the liquid crystal, it is possible to block the propagation of the elastic force of the liquid crystal alignment that occurs between the pixels. By giving the fine space for liquid crystal filling separated by this wall structure shape anisotropy in directions orthogonal to each other in the plane of the base, it is possible to regulate the alignment by utilizing the elasticity of the liquid crystal. This discovery led to the completion of the present invention.

A. Liquid crystal alignment member for spatial light phase modulation The liquid crystal alignment member for spatial light phase modulation of the present disclosure includes a silicon substrate, and pixel electrodes arranged in a matrix with a period of 3 μm or less, provided on the surface of the silicon substrate. a lattice-like wall structure in which a plurality of linear protrusions are combined, arranged on the base part and made of a dielectric material, and separated from each other by the lattice-like wall structure; Further, the lattice-like wall structure has a plurality of liquid crystal filling micro spaces on the base portion for filling the liquid crystal, and the lattice-like wall structure has at least a space between the pixel areas where the adjacent pixel electrodes are formed. The fine space for liquid crystal filling is characterized in that it has shape anisotropy in directions orthogonal to each other in the plane of the base portion.

In the liquid crystal alignment member for spatial light phase modulation of the present disclosure, the lattice-shaped wall structure is arranged at least between pixel regions in which the above-mentioned adjacent pixel electrodes are formed, and the fine spaces for liquid crystal filling are arranged in the lattice-shaped wall structure. Because they are divided by structure, when filled with liquid crystal and used as a light modulation element, even if the pixel pitch is as narrow as 3 μm or less, electric field leakage from adjacent pixels and propagation of liquid crystal elastic force are blocked. be able to. At the same time, one or more liquid crystal filling micro spaces corresponding to each of the pixel electrodes having a narrow pixel pitch of 3 μm or less have shape anisotropy in mutually orthogonal directions in the base plane. Since the structure itself can have a liquid crystal alignment function, it is possible to align the liquid crystal even if there is no alignment film on the base. Therefore, it becomes possible to easily control the orientation of the liquid crystal independently in each pixel.

Such a liquid crystal alignment member for spatial light phase modulation (hereinafter also simply referred to as an alignment member) of the present disclosure will be described with reference to the drawings. FIG. 1(A) is a top view showing an example of the alignment member of the present disclosure, and FIG. 1(B) is a schematic cross-sectional view taken along line A-A' in FIG. 1(A). As illustrated in FIG. 1, the alignment member 100 of the present disclosure includes a base portion 3 including a substrate 1 and pixel electrodes 2 provided on the surface of the substrate and formed in a matrix with a period of 3 μm or less; It has a lattice-like wall structure 4 which is arranged on the base part 3 and is made of a dielectric material and which is a combination of a plurality of linear convex parts. In FIG. 1 , the lattice-like wall structure 4 is composed of a wall portion 41 and a partition portion 42 . The lattice-like wall structure 4 is arranged at least between adjacent pixel regions in which the pixel electrodes 2 are formed. Each liquid crystal filling microspace 5 partitioned by the lattice-like wall structure 4 has anisotropy in shape in directions perpendicular to each other in the plane of the base (X-axis direction and Y-axis direction in FIG. 1). In FIG. 1, two fine spaces 5 for filling liquid crystal are formed on one pixel electrode 2. Further, in FIG. 1 , a base layer 6 is present between the lattice-like wall structure 4 and the base portion 3 . Hereinafter, the alignment member of the present disclosure will be described in detail.

1. Silicon Substrate In the present disclosure, the substrate on which the pixel electrode is provided is a silicon substrate. Using a silicon substrate, it is possible to fabricate a minute device with a pixel electrode period of 3 μm or less.
The film thickness of the silicon substrate is not particularly limited, but is usually within the range of 280 μm to 775 μm. Further, its size in plan view is usually about 50 mmφ to 300 mmφ.

2. Pixel Electrode Pixel electrodes for driving display pixels in the present disclosure are arranged in a matrix on the surface of a silicon substrate with a period of 3 μm or less. These pixel electrodes define a plurality of pixels of the spatial light modulation element. "Matrix shape" may be a one-dimensional matrix array arranged only in the X-axis direction, or a two-dimensional matrix array arrayed in the X-axis direction and the Y-axis direction perpendicular to the X-axis direction. There may be. Usually, pixel electrodes are arranged in a two-dimensional matrix.

In the present disclosure, the period of a pixel electrode refers to the distance between the centers of adjacent pixel electrodes. Further, when the pixel electrodes are arranged in a one-dimensional matrix, the period of adjacent pixel electrodes is 3 μm or less, and the pixel electrodes are arranged in a two-dimensional matrix in the X-axis direction and the Y-axis direction. In this case, if the periods in the X-axis direction and the Y-axis direction are the same, the period is 3 μm or less, and if they are different, the shorter period is 3 μm or less. In the present disclosure, when the pixel electrodes are arranged in a two-dimensional matrix, it is preferable that the period in both the X-axis direction and the Y-axis direction is 3 μm or less.

Even if the pixel pitch is as narrow as 3 μm or less, the alignment member of the present disclosure allows the liquid crystal to be controlled independently for each pixel region when filled with liquid crystal and used as a light modulation element. I can do it.
In addition, in the present disclosure, the period may be 3 μm or less (in this case, the viewing angle is 10.5° or more), but it is preferable that it is 1 μm or less because a practical viewing angle of 30° can be obtained. .

The surface of the pixel electrode is usually processed to be flat and smooth, and the pixel electrode on the silicon substrate functions as a reflector.

The pixel electrode is not particularly limited as long as it is made of a conductive material, and examples thereof include Al, Cr, Cu, Ag, Ta, Mo, Nd, and alloys thereof. Furthermore, a dielectric multilayer film with high reflectance may be laminated on the surface.

The shape of the pixel electrode in plan view is not particularly limited, but is usually either rectangular or square. Further, the size of the pixel electrode is not particularly limited as long as the period of the pixel electrode is 3 μm or less.

The thickness of the pixel electrode is not particularly limited as long as it can ensure conductivity, and known techniques can be used.
Furthermore, although it is desirable that the pixel electrodes be arranged in a matrix in the X and Y directions, the arrangement is not limited thereto.

The method for forming the pixel electrode is not particularly limited as long as it can be formed to a desired thickness and pattern, and a general method for forming a pixel electrode can be used. Specifically, PVD methods such as a vacuum evaporation method, a sputtering method, an ion plating method, a CVD method, a method of applying a conductive paste, an inkjet method, a screen printing method, a flexo printing method, a plating method, etc. can be mentioned.

3. Base Part The base part in the present disclosure includes at least a silicon substrate and a pixel electrode. The silicon substrate and the pixel electrode are the same as those described in "1. Silicon substrate" and "2. Pixel electrode" above, respectively, so their description will be omitted here.

4. Lattice-shaped wall structure The lattice-shaped wall structure in the present disclosure is formed on a base portion, is made of a dielectric material, and has a structure in which linear convex portions are combined.

In the present disclosure, the material constituting the lattice-like wall structure is not particularly limited as long as it is a dielectric material and can be microfabricated by nanoimprinting, etching, or the like. Among dielectric materials, it is preferable to use a low dielectric material, particularly a material with a dielectric constant of 4.0 or less, more preferably 2.0 or less.
Specific examples of materials that can be subjected to nanoimprint processing include thermosetting resins and photocurable resins, with photocurable resins being particularly preferred. Furthermore, when the photocurable resin is used, it is preferably a transparent resin.
Among the materials constituting such a lattice-like wall structure, acrylic resin, coated glass, glass, etc. are preferable.

Furthermore, by using a material in which a black pigment is mixed into the above material, unmodulated light can be absorbed. Such a black pigment is the same as that described in the section "A. Liquid crystal alignment member for spatial optical phase modulation 7. Others (2) Light absorption layer" described later, so the explanation here will be omitted. .

The lattice-like wall structure is a structure in which a plurality of linear convex portions are combined, preferably a structure in which linear convex portions orthogonal to each other are combined.

As shown in FIG. 1, between the lattice-like wall structure 4 and the base part 3 there may be a base layer 6. Such a base layer 6 is normally formed in the manufacturing process when arranging the lattice wall structure 4, but may be removed after formation. FIG. 2 shows a schematic diagram of the alignment member of the present disclosure without a base layer.

Although the thickness of the lattice-like wall structure is not particularly limited, it is preferably 50 nm or more and 400 nm or less, and more preferably 200 nm or less.
Here, the thickness of the lattice-like wall structure refers to the thickness at the non-intersecting portions of the linear convex portions, as shown by (W41) and (W42) in FIG.

Further, the height of the lattice-like wall structure is not particularly limited, but it is preferably 500 nm or more and 3000 nm or less, and more preferably 800 nm or more and 1500 nm or less.

Here, as shown in (H) in FIG. 1, when the alignment member 100 includes the base layer 6, the height of the lattice-like wall structure 4 is perpendicular to the in-plane direction of the base layer 6. It refers to the length from the first surface 6A of the base layer 6 in the direction to the top 4A of the wall structure 4 (linear convex portion). Further, as shown in FIG. 2, when the alignment member 100 does not include the base layer 6, the height of the lattice-like wall structure 4 in the direction perpendicular to the in-plane direction of the silicon substrate 1 is It means the length from the first surface 1A of the silicon substrate 1 to the top 4A of the wall structure 4 (linear convex portion).

In the present disclosure, the height H of all the linear protrusions included in the wall structure 4 may be within the above numerical range, but the height H of some linear protrusions may be outside the above numerical range. Good too. The height H of the wall structure 4 can be measured using, for example, a scanning electron microscope.

In the present disclosure, as shown in FIG. 1, the lattice-like wall structure 4 is roughly divided into a wall part 41 provided between adjacent pixel areas, and a partition part 42 that divides one pixel area into two or more parts. I can do it. The wall portion and the partition portion will be described in detail below.

(1) Wall portion The wall portion is provided to separate adjacent pixel regions, that is, to surround each pixel region. When the pixel area does not have shape anisotropy as shown in FIG. 1, it is necessary to provide a partition section, which will be described later. However, as shown in FIG. 3, when the pixel area itself has shape anisotropy, , the lattice-like wall structure 4 may be composed of only the wall portions 41. In addition, in FIG. 3(A), the base layer 6 is omitted for convenience of explanation.

(a) Thickness The thickness of the wall portion is not particularly limited, but is preferably 200 nm or more and 400 nm or less. More preferably, it is 200 nm or more and 250 nm or less. If it is less than or equal to the above value, a sufficiently wide fine space for filling the liquid crystal can be secured. Furthermore, if the value is above the above value, it is possible to reliably block the leakage of the electric field from adjacent pixels and the propagation of the elastic force of liquid crystal alignment, making it possible to control the alignment of the liquid crystal to be filled. .

(b) Height The height of the wall portion is not particularly limited, but is preferably 500 nm or more and 3000 nm or less, and more preferably 800 nm or more and 1500 nm or less.
With such a height (that is, the thickness of the liquid crystal layer), phase modulation with a sufficient width for 2π, which is the ideal amount of modulation, is possible.

(2) Partition Part The partition part divides the pixel area into two or more parts. In the case of dividing into two or more, as long as the alignment of the liquid crystal can be controlled, there is no particular limitation, but the division is provided in one or both of the X-axis direction, the Y-axis direction, which is the arrangement direction of the pixel electrodes. Furthermore, although it is usually desirable that the partition section be connected to the wall so that the pixel area is completely divided and that there is no gap between the partition section and the wall section, it is not necessary to connect the partition section. good. Note that normally, the partition section divides the pixel area into two or more equal parts.

The partition portion is provided so as to divide one pixel region into two or more, that is, to form two or more fine spaces for liquid phase filling corresponding to one pixel region. FIG. 4 shows a top view (A) and a schematic cross-sectional view (B) of an embodiment in which partition portions 42 are provided so as to divide one pixel region into three equal parts. Note that in FIG. 4(A), the base layer 6 is omitted for convenience.

(a) Thickness The thickness of the partition part is not particularly limited, but is preferably 50 nm or more and 400 nm or less, more preferably 50 nm or more and 200 nm or less. If the thickness is less than this, it is possible to ensure a sufficient aperture ratio and increase light utilization efficiency.

(b) Height The height of the partition is not particularly limited, but is preferably from 500 nm to 3000 nm, more preferably from 500 nm to 1500 nm.
Such a height is sufficient to provide the fine space for liquid crystal filling with a liquid crystal alignment function.

In the present disclosure, as shown in FIG. 1, the heights of the wall portion 41 and the partition portion 42 may be the same, or as shown in FIG. 5, the heights of the wall portion 41 and the partition portion 42 may be different. It's okay.
In this way, when the heights of the partition and the wall are different, the partition is usually formed so that the height of the partition is smaller than the height of the wall. In this case, the height of the partition is preferably 50 or more, particularly preferably 80 or more when the height of the wall is 100. This is because if the height of the partition portion is smaller than the above range, the liquid crystal alignment function may not be sufficient.

5. Microspace for Liquid Crystal Filling The plurality of microspaces for liquid crystal filling in the present disclosure are separated from each other by a lattice-like wall structure, that is, each microspace for liquid crystal filling is a space surrounded by linear convex portions. This fine space for liquid crystal filling has anisotropy in shape in directions orthogonal to each other in the plane of the base to the extent that the liquid crystal is oriented. Since the space has such anisotropy, it is possible to control the orientation of the liquid crystal to be filled.

In particular, it is preferable that each fine space for liquid crystal filling has anisotropy in shape in the X-axis direction and the Y-axis direction, which are the arrangement directions of the pixel electrodes. Preferably, the lengths are different. The XY plane shape of such a fine space for liquid crystal filling is not particularly limited, but includes shapes having a long side (long axis) and a short side (short axis), such as a rectangle, an ellipse, and a parallelogram.

In the present disclosure, the first axis of the pixel electrodes arranged in a matrix is aligned with the matrix direction, that is, the short side (short axis) direction, and the first axis is parallel to the base portion. A second axis is taken in a direction perpendicular to the first axis in the plane, that is, in the long side (long axis) direction, and the space width in the first axis direction in the liquid crystal filling microspace is A, and the second axis is When the space width in the axial direction is B, it is preferable that A is 3 μm or less and that A is a smaller value than B. The space width A in the first axial direction is preferably short, preferably 0.6 μm or less, and particularly preferably 0.3 μm or less.

In addition, the ratio of the length in the long side (long axis) direction to the short side (minor axis) direction (i.e., the ratio of B to A (B/A)) in the liquid crystal filling microspace is approximately 2 or more. It is preferably 2.5 or more, particularly preferably 2.5 or more. Note that the upper limit is not particularly limited and may be infinite, but usually it can be set to 10 or less. Within this range, the shape anisotropy in the mutually orthogonal directions in the plane of the base is sufficient, so it is possible to reliably control the alignment of the liquid crystal by utilizing the elasticity of the liquid crystal to be filled. Become.

At the bottom of the fine space for liquid crystal filling, as shown in FIG. 1, there may be a base layer 6 made of dielectric material remaining in the process of forming the convex structure, or as shown in FIG. , such a base layer may be removed and the pixel electrode 2 may be exposed.

6. Applications The liquid crystal alignment member for spatial light phase modulation of the present disclosure is suitably used as a liquid crystal alignment member for a reflective spatial light modulation element that controls the phase of incident light and reflected light while reflecting incident light.
Furthermore, with the alignment member of the present disclosure, it is possible to obtain a light modulation element with a pixel pitch of 3 μm or less, in which liquid crystal can be controlled independently for each pixel region. Therefore, when the liquid crystal alignment member for spatial light phase modulation of the present disclosure is used in a display device, it is possible to secure a wide angular range in which the reproduced image can be observed. It can be suitably used for holographic displays, stereoscopic display devices, etc.

7. Others (1) Adhesion layer In the present disclosure, an adhesion layer can be formed in order to improve the adhesion between the base and the convex structure. The adhesion layer is not particularly limited as long as it can enhance the adhesion between the base and the convex structure, and any known material can be used as the adhesion layer material, such as a silane coupling material. Examples include.

(2) Light absorption layer In order to prevent the emission of unmodulated light, a light absorption layer is applied to the surface of the base excluding the area where the pixel electrode is formed (pixel area) and the surface layer of the lattice-like wall structure. It is preferable to provide one. The light absorption layer can contain, for example, a binder resin and a black pigment. Examples of the black pigment include titanium black such as lower titanium oxide and titanium oxynitride, and carbon black. Moreover, it is preferable that the binder resin serving as the main component of the light absorbent contains a photosensitive resin. Examples of the photosensitive resin include photosensitive resins having photoreactive groups such as reactive vinyl groups such as acrylic resins, epoxy resins, polyimide resins, polyvinyl cinnamate resins, and cyclized rubber. More than one species can be used. As the acrylic resin, for example, a photosensitive resin consisting of an alkali-soluble resin, a polyfunctional acrylate monomer, a photopolymerization initiator, other additives, etc. can be used as a resin component of the binder resin. In addition to the above-mentioned materials, the binder resin can also contain various known additives such as photosensitizers, dispersants, surfactants, stabilizers, and leveling agents.

(3) Notch, spacer In order to improve the fluidity when filling the liquid crystal, a spacer may be partially formed at the top of the lattice-like wall structure. FIG. 6 is a schematic diagram showing a mode in which spacers 61 are formed on intersections of linear convex portions in a lattice-like wall structure. By providing such a spacer, the height of the location where the spacer is formed can be made different from the height of other wall structures, and the liquid crystal can be filled with good fluidity. This spacer can be integrally formed of the same material as the lattice wall structure. Further, in order to improve the fluidity when filling the liquid crystal, a notch portion may be partially provided at the top of the lattice-like wall structure.

8. Manufacturing Method Next, an example of a method for manufacturing the liquid crystal alignment member for spatial phase conversion of the present disclosure will be described. The liquid crystal alignment member for spatial light phase modulation of the present disclosure can be manufactured by arranging a lattice-like wall structure on a silicon substrate having a pixel electrode. The lattice-like wall structure in the present disclosure can be manufactured using various known processing techniques for forming high-definition patterns, such as nanoimprinting, etching, etc. In particular, the lattice-like wall structure can be manufactured using nanoimprinting. It is preferable to do so. The manufacturing method using the nanoimprint method involves forming a dielectric layer on a base using a dielectric material such as a photocurable resin, pressing a mold with a corresponding pattern on it, then curing it by light irradiation, etc. It can be manufactured by removing. Alternatively, it can also be manufactured by separately preparing a lattice-like wall structure using a nanoimprint method or the like, and bringing this lattice-like wall structure into close contact with the base.

B. Spatial Light Modulator A schematic cross-sectional view showing an example of the spatial light modulator of the present disclosure is shown in FIG. As shown in FIG. 10, the spatial light modulation element 101 of the present disclosure is a reflective spatial light phase modulation element 101 that controls the phase of the incident light and the reflected light while reflecting the incident light. , the common electrode 9 formed on the transparent substrate, the alignment film 10, the above-mentioned liquid crystal alignment member 100 for spatial light phase modulation, and filling the fine spaces for liquid crystal filling in the liquid crystal alignment member for spatial light phase modulation. The liquid crystal layer 7 is characterized in that it has a liquid crystal layer 7. Hereinafter, the spatial light modulation element of the present disclosure will be explained.

1. Transparent Substrate The transparent substrate constitutes the surface of the spatial light modulator, and transmits light of a predetermined wavelength incident from the surface of the spatial light modulator into the interior of the spatial light modulator. As the transparent substrate, existing plastic substrates such as glass materials, polycarbonate-based, acrylic-based, polyimide-based, polystyrene-based, and polyolefin-based materials can be used.

2. Common Electrode The common electrode is formed on the back surface of the transparent substrate, and a general transparent electrode can be used. Specifically, ITO, IZO, etc. can be mentioned.

3. Liquid crystal alignment member for spatial light phase modulation The liquid crystal alignment member for spatial light phase modulation used in the spatial light modulation element of the present disclosure is the same as that described in the above “A. Liquid crystal alignment member for spatial light phase modulation”. , the explanation here is omitted.

4. Liquid Crystal Layer The liquid crystal layer in the present disclosure is not particularly limited as long as it is a liquid crystal having dielectric anisotropy that is normally used in light modulation elements. For example, a nematic crystal with excellent responsiveness is preferable, and in particular a cyano crystal or a fluorine crystal. Liquid crystals of the type, biphenyl type, terphenyl type, and tolan type are useful. In a phase modulation element, a liquid crystal material that has a higher dielectric constant in the long axis direction than in the short axis direction has a larger refractive index difference between the long axis direction and the short axis direction, and thus can easily obtain a high degree of modulation. Therefore, it is preferable to use the above-mentioned nematic liquid crystal which has a higher dielectric constant in the long axis direction of the molecules.

The liquid crystal layer modulates light according to the electric field formed by each pixel electrode. That is, when a voltage is applied to a certain pixel electrode by a driving means to be described later, an electric field is formed between the common electrode and the pixel electrode. Then, the alignment direction of the liquid crystal molecules changes depending on the magnitude of the electric field applied to the liquid crystal layer. When light passes through the transparent substrate and common electrode and enters the liquid crystal layer, this light is modulated by the liquid crystal alignment structure while passing through the liquid crystal layer, reflected at the pixel electrode, and then modulated by the liquid crystal layer again before being extracted. It will be done. At this time, the alignment direction of the liquid crystal molecules changes within the slope. As a result, the refractive index of the liquid crystal layer changes depending on the pixel position. The readout light incident on the liquid crystal layer is phase-modulated by this change in refractive index, reflected by the pixel electrode, and output again from the incident surface.

5. Alignment film In order to strengthen the regulating force for aligning liquid crystal molecules in a certain direction and to define the pretilt angle, an alignment film may be formed on the end surface of the liquid crystal layer on the common electrode side. Known alignment films can be used, such as those made of a polymeric material such as polyimide and subjected to a rubbing treatment on the contact surface with the liquid crystal layer, a photo-alignment film that is oriented by light irradiation, An obliquely deposited film of SiOx or the like can be applied.

6. Manufacturing method In the spatial light modulation element of the present disclosure, the above-described liquid crystal alignment member for spatial light phase modulation and a transparent substrate having a common electrode are fixed in position with a sealing material or the like, and the liquid crystal is placed under vacuum. It can be manufactured by injecting it in a vacuum or by dropping it under vacuum before bonding the substrates together.
In the present disclosure, if necessary, an alignment member may be placed in advance on the transparent substrate having the common electrode.
Further, on the transparent substrate side, the lattice-like wall structure explained in "A. Liquid crystal alignment member for spatial light phase modulation 4. Lattice-like wall structure" is arranged, and after injecting the liquid crystal, this and "A. Liquid crystal aligning member for optical phase modulation 3. The base portion described in “3. Base portion” may be sealed with a sealing material or the like.

C. Stereoscopic Display Device The present disclosure provides a stereoscopic display device characterized by comprising the above-described spatial light modulation element and a driving means for driving the pixel electrode.

1. Spatial Light Modulation Element The spatial light modulation element used in the stereoscopic display device of the present disclosure is the same as that described in "B. Spatial Light Modulation Element" above, so the description here will be omitted.

2. Driving Means The driving means for driving the pixel electrodes is means for controlling the voltage applied to each pixel electrode according to the optical image to be output from the spatial light modulation element. For example, it has a first driver circuit that controls the applied voltage to each pixel column arranged in the X-axis direction, and a second driver circuit that controls the applied voltage to each pixel column arranged in the Y-axis direction. , a predetermined voltage is applied between the pixel electrode 4 of the pixel specified by both driver circuits and the common electrode. This generates an electric field in the liquid crystal layer. For example, it is possible to construct a stereoscopic display device that forms a three-dimensional spatial light image at an arbitrary position by inputting light into the above-described spatial light modulation element and controlling the interference of the emitted light. Alternatively, a glasses-type stereoscopic display device can be constructed using a reflective optical system.

Note that the present disclosure is not limited to the above embodiments. The above-mentioned embodiments are illustrative, and any embodiment that has substantially the same configuration as the technical idea stated in the claims of the present disclosure and provides similar effects is the present invention. within the technical scope of the disclosure.

Examples and Comparative Examples are shown below to further specifically explain the present disclosure. In addition, in the following Examples and Comparative Examples, a glass substrate was used instead of a silicon substrate for observation using a polarizing microscope.

(Example 1)
Cr pixel electrodes with a square planar shape (700 nm x 700 nm) were arranged in a two-dimensional matrix at a pitch of 1 μm in the X-axis and Y-axis directions on a glass substrate to serve as a base. Next, an acrylic resin layer made of a photocurable resin containing acrylate as a main raw material was formed on the base, nanoimprint processing was performed, and a lattice-like wall structure was provided on the base to produce an alignment member. The lattice-like wall structure has a wall part that partitions adjacent pixel areas, and a partition part that divides each pixel area into two equal parts. The width of the wall part is 198 nm, the width of the partition part is 148 nm, the height of both the wall part and the partition part is 812 nm, the thickness of the base layer is 204 nm, the length of the liquid crystal filling microspace in the X-axis direction is 327 nm, The length in the axial direction was 802 nm.

(Example 2)
The width of the wall part is 198 nm, the width of the partition part is 169 nm, the height of both the wall part and the partition part is 813 nm, the thickness of the base layer is 204 nm, the length of the fine space for liquid crystal filling in the X-axis direction is 320 nm, and Y An alignment member was manufactured in the same manner as in Example 1 except that the length in the axial direction was 808 nm.

(Example 3)
The width of the wall part is 190 nm, the width of the partition part is 190 nm, the height of both the wall part and the partition part is 810 nm, the thickness of the base layer is 178 nm, the length of the liquid crystal filling microspace in the X-axis direction is 310 nm, and the Y An alignment member was manufactured in the same manner as in Example 1 except that the length in the axial direction was 810 nm.

(Comparative example 1)
As shown in FIG. 9, Cr pixel electrodes 92 having a square planar shape (700 nm x 700 nm) are arranged in a two-dimensional matrix at a pitch of 1 μm in the X-axis and Y-axis directions on a glass substrate 91. And so. Next, an acrylic resin layer made of a photocurable resin mainly made of acrylate is formed on the base, nanoimprint processing is performed, a lattice-like wall structure 94 is provided on the base, and the alignment member 90 is manufactured. did. The lattice-like wall structure had only wall portions that separated adjacent pixel regions, and the width of the wall portion was 196 nm, and the height of the wall portion was 838 nm. The shape of the fine space for liquid crystal filling in the base plane was square, and the lengths in both the X-axis direction and the Y-axis direction were 779 nm.

(evaluation)
The fine spaces for liquid crystal filling in the alignment members manufactured in Examples 1 to 3 and Comparative Example 1 were filled with a liquid crystal material, and a polycarbonate substrate on which a common electrode made of IZO and an alignment film were formed was placed, with the polycarbonate substrate serving as the outermost surface. A spatial light modulation element was manufactured by fixing the periphery with a sealing material and stacking them. As the liquid crystal material, a nematic liquid crystal cyanobiphenyl E7 (manufactured by Merck & Co., Ltd.) was used, and as the alignment film, a polyimide rubbing alignment film AL1254 (manufactured by JSR Corporation) was used.
Note that FIG. 10 shows a schematic cross-sectional view of a spatial light modulation element using the alignment member manufactured in Example 1.

Two polarizing plates were arranged in a crossed nicol state shifted by 90°, and a spatial light modulation element using the alignment member manufactured in Example 1 was placed between the polarizing plates, and the brightness and darkness were observed. Figure 11(a) shows the polarization microscope observation results when the angular difference between the Y-axis direction and the polarization direction of the polarizing plate is 45° as shown in Figure 10, and when the angular difference between the Y-axis direction and the polarization direction of the polarizing plate is 0°. The results of observation using a polarizing microscope at the time are shown in FIG. 11(b). Similarly, FIG. 11 (c ), and FIG. 11(d) shows the results of polarization microscope observation when the angular difference between the Y-axis direction and the polarization direction of the polarizing plate is 0°.

In Example 1, when the angular difference between the Y-axis direction and the polarization direction of the polarizing plate shown in FIG. When the angle was 0°, the state was almost completely black (FIG. 11(b)). Moreover, Examples 2 and 3 also gave similar results. On the other hand, in Comparative Example 1, when the angular difference between the Y-axis direction and the polarization direction of the polarizing plate is 45 degrees, the transmittance is lower than in Examples 1 to 3 (Fig. 11(c)). When the angular difference in the polarization direction of the polarizing plate was 0°, the transmittance was higher than in Examples 1 to 3, and a black state did not occur (FIG. 11(d)). From the above, it is considered that in the example, the alignment of the liquid crystal could be aligned by the lattice-like wall structure of the present disclosure.

(Examples 4-1 to 4-7, Comparative Example 2)
The aspect ratio ( [Ly/Lx]) was manufactured by the following method, and the influence of the shape anisotropy of the liquid crystal filling microspace on the liquid crystal alignment was evaluated by the evaluation method described below. At this time, for Comparative Example 2 and Examples 4-1 to 4-6, the aspect ratio was increased by reducing the length (Lx) in the X-axis direction, but for Example 4-7, The experiment was conducted by increasing the aspect ratio by increasing the length (Ly) in the Y direction.

An acrylic resin layer made of a photocurable resin containing acrylate as the main raw material is formed on a glass substrate, and nanoimprint processing is performed on the acrylic resin layer to form a liquid crystal filling microspace having Lx and Ly in Table 1 on the glass substrate. A lattice-like wall structure was provided to produce an alignment member sample. Next, the fine spaces for liquid crystal filling in the produced alignment member are filled with a liquid crystal material, and the polycarbonate substrates on which the alignment film is formed are stacked with the polycarbonate substrates on the outermost surface, fixing the periphery with a sealing material, and space light is applied. A modulation element sample was fabricated. As the liquid crystal material, a nematic liquid crystal cyanobiphenyl E7 (manufactured by Merck & Co., Ltd.) was used, and as the alignment film, a polyimide rubbing alignment film AL1254 (manufactured by JSR Corporation) was used. Incidentally, a schematic perspective view of the manufactured spatial light modulation element sample is shown in FIG. 12(a). 51 is a substrate, 57 is a liquid crystal, 54 is a wall structure, and 60 is an alignment film.

(Evaluation method)
Two polarizing plates are arranged in a crossed nicol state shifted by 90 degrees, and a spatial light modulation element sample using the manufactured alignment member is placed between these polarizing plates, and the angular difference between the Y-axis direction and the polarization direction of the polarizing plates is The ratio (R) between the average transmittance in the bright state (T _{45° ) when the angle is 45°} and the average transmittance in the dark state (T ₀ ° ) when the angle difference is 0° is calculated using the following formula. and used it as an evaluation index.
R=(T _45° )/(T _0° )
If the liquid crystal is uniformly aligned, the polarization axis will rotate when the polarized light passes through the liquid crystal, and the polarized light will pass through the polarizing plates arranged in a crossed nicol configuration. In other words, the higher the average transmittance ratio R, the more uniformly the liquid crystal is aligned. The results are shown in Table 1 and FIG. 12(b).

From the results shown in Table 1 and FIG. 12(b), it was found that, compared to Comparative Example 2 in which the aspect ratio was 1, the embodiments in which the aspect ratio was greater than 1 were able to align the alignment of the liquid crystal. In particular, when the aspect ratio was 2 or more (Examples 4-4 to 4-7), the average transmittance ratio was significantly high. Nematic liquid crystals are oriented in such a way that the elastic energy of the liquid crystal settles down to a small state. However, when the aspect ratio of the lattice walls is small as in Comparative Example 2, the liquid crystals are oriented so that the elastic energy of the liquid crystals settles down to a small state. However, when the aspect ratio of the lattice walls is small as in Comparative Example 2, the liquid crystals are As a result, the liquid crystal alignment is disturbed inside the pixel, resulting in a distorted and unstable state. On the other hand, when the aspect ratio of the lattice walls is increased as in Examples 4-4 to 4-7, the liquid crystal alignment state parallel to the long side direction of the lattice walls has the smallest elastic energy and becomes a stable state. It is considered that a uniform initial orientation was achieved in the long side direction.

(Example 5-1 to Example 5-5)
The aspect ratio of the length (Lx) in the X-axis direction and the length (Ly) in the Y-axis direction of the fine space for liquid crystal filling divided by the lattice-like wall structure was set to 2, which was proven to be effective in Example 4. The alignment member was manufactured in the same manner as in Example 4, except that the size (Lx, Ly) of the fine space for liquid crystal filling was changed, and the size (Lx, Ly) of the fine space for liquid crystal filling was almost fixed to the above (approximately 2.4 to 2.7). The spatial light modulator sample used was fabricated. The average transmittance ratio R was calculated by a method similar to the above (evaluation method), and the ratio of the average transmittance ratio R of each Example was calculated based on the average transmittance ratio of Example 5-1. The results are shown in Table 2 and FIG. 13.

From Table 2, it was found that the smaller the value of Lx (space width A in the first axial direction), the higher the average transmittance ratio. In particular, when Lx was 0.3 μm or less (Examples 5-3 to 5-5), the average transmittance ratio was significantly high. When the grating size is small as in Examples 5-3 to 5-5, a sudden alignment deformation is forced within the pixel and the elastic energy density increases, so the alignment in the long axis direction becomes more dominant, and as a result This is considered to be the result of an increase in the uniformity of the orientation distribution.

(Reference example 1 to reference example 5)
In order to investigate the influence of the length (Lx) in the X-axis direction of the fine space for liquid crystal filling divided by a lattice-like wall structure, a wall structure in which linear convex portions were arranged in parallel was formed, and Lx was varied. Except for the above, an alignment member was manufactured in the same manner as in Example 4, and a spatial light modulation element sample using the alignment member was fabricated. The average transmittance ratio R was calculated by a method similar to the above (evaluation method), and the ratio of the average transmittance ratio R of each reference example based on the average transmittance ratio of Reference Example 1 was calculated. The results are shown in Table 3 and FIG. 14.

From Table 3, it was found that the smaller the width of Lx, the higher the average transmittance ratio; for example, if it is 3 μm or less, the average transmittance ratio becomes higher. This is because if the length (Lx) in the X-axis direction of the fine space for liquid crystal filling is small, for example 3 μm or less, the liquid crystal between the walls will be subject to a strong regulating force, making it possible to align the alignment of the liquid crystal more reliably. This seems to suggest that it is possible.

1...Silicon substrate 2...Pixel electrode 3...Base part 4...Lattice-like wall structure 41...Wall part 42...Partition part 5...Minute space for liquid crystal filling 6...Base layer 7...Liquid crystal layer 8...Transparent substrate 9...Common Electrode 10...Alignment layer 100...Liquid crystal alignment member for spatial light phase modulation 101...Spatial light modulation element

Claims (9)

a base portion comprising a silicon substrate and pixel electrodes provided on the surface of the silicon substrate and arranged in a matrix with a period of 3 μm or less;
a lattice-like wall structure in which a plurality of linear protrusions are combined, made of a dielectric material, and arranged on the base;
a plurality of liquid crystal filling fine spaces on the base portion, separated from each other by the lattice-like wall structure, for filling liquid crystal;
The lattice-like wall structure is arranged at least between pixel regions in which adjacent pixel electrodes are formed, and the liquid crystal filling microspace has shape anisotropy in mutually orthogonal directions in the base plane. A liquid crystal aligning member for spatial light phase modulation, comprising: A first axis of the pixel electrodes arranged in a matrix is aligned in a direction coinciding with the matrix direction, and a second axis is aligned in a direction orthogonal to the first axis in a plane parallel to the base portion. Take
When the space width in the first axial direction in the liquid crystal filling microspace is A and the space width in the second axial direction is B, A is 3 μm or less, and A is a smaller value than B. The liquid crystal aligning member for spatial light phase modulation according to claim 1, characterized in that: The liquid crystal alignment member for spatial optical phase modulation according to claim 2, wherein a ratio (B/A) of the spatial width B in the second axial direction to the spatial width A in the first axial direction is 2 or more. Claims 1 to 3 , wherein the lattice-like wall structure is comprised of a wall part that separates the adjacent pixel areas, and a partition part that divides each pixel area into two or more parts. A liquid crystal alignment member for spatial light phase modulation according to any one of the preceding claims . The liquid crystal alignment member for spatial optical phase modulation according to any one of claims 1 to 4 , wherein the thickness of the lattice-like wall structure is 50 nm or more and 400 nm or less. The liquid crystal aligning member for spatial light phase modulation according to claim 5 , wherein the lattice-like wall structure has a height of 500 to 3000 nm. A reflective spatial light phase modulation element that controls the phase of incident light and reflected light while reflecting incident light,
A transparent substrate, a common electrode disposed on one surface of the transparent substrate, and a common electrode disposed on a surface of the common electrode opposite to the transparent substrate. A spatial light modulation element comprising: a liquid crystal alignment member for spatial light phase modulation according to item 1; and a liquid crystal layer filled in the fine spaces for filling liquid crystal in the liquid crystal alignment member for spatial light phase modulation. . 8. The spatial light modulation element according to claim 7, wherein an alignment film is disposed between the common electrode and the liquid crystal alignment member for spatial light phase modulation. A three-dimensional display device comprising the spatial light modulation element according to claim 7 or claim 8, and driving means for driving the pixel electrode.