Liquid crystal element and spatial light modulation device

Abstract

A liquid crystal element according to an embodiment of the present disclosure comprises a first substrate having a first electrode provided to each of a plurality of pixels, a second substrate having a second electrode provided so as to face the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate and having a first region and a second region. The first region has a first structure having a columnar shape. The optical layer can modulate light in a first wavelength region incident on the first region, and can modulate light in a second wavelength region incident on the second region.

Description

Liquid crystal element and spatial light modulator

[0001] The present disclosure relates to a liquid crystal element and a spatial light modulator.

[0002] A phase modulation element having a plurality of divided regions filled with liquid crystal materials having different refractive index anisotropies Δn from each other has been proposed (Patent Document 1).

[0003] International Publication No.: WO2022 / 050028

[0004] In an element that modulates light, it is desirable to be able to support high image quality.

[0005] It is desired to provide a liquid crystal element advantageous for high image quality.

[0006] The liquid crystal element according to an embodiment of the present disclosure includes a first substrate having a first electrode provided for each of a plurality of pixels, a second substrate having a second electrode provided so as to face the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate and having a first region and a second region. The first region has a first structure having a columnar shape.the optical layer is capable of modulating light in a first wavelength range incident on the first region and capable of modulating light in a second wavelength range incident on the second region. The spatial light modulator according to an embodiment of the present disclosure includes a liquid crystal element and a control unit capable of controlling the liquid crystal element. The liquid crystal element includes a first substrate having a first electrode provided for each of a plurality of pixels, a second substrate having a second electrode provided so as to face the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate and having a first region and a second region. The first region has a first structure having a columnar shape. The optical layer is capable of modulating light in a first wavelength range incident on the first region and capable of modulating light in a second wavelength range incident on the second region.

[0007] Figure 1 is a diagram showing an example of the schematic configuration of a spatial light modulation device according to an embodiment of the present disclosure. Figure 2 is a diagram showing an example of the pixel portion of a liquid crystal element according to an embodiment of the present disclosure. Figure 3 is a diagram showing an example of the schematic configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 4 is a diagram showing an example of the planar configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 5 is a diagram showing an example of the schematic configuration of a spatial light modulation device according to an embodiment of the present disclosure. Figure 6 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 7 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 8 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 9 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 10 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 11 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 12 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 13 is a diagram for explaining an example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 14 is a diagram illustrating another example of the configuration of a liquid crystal element according to an embodiment of the present disclosure. Figure 15A is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 15B is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 15C is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 15D is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 15E is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 15F is a diagram illustrating an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment of the present disclosure. Figure 16 is a diagram illustrating an example of the configuration of a liquid crystal element according to Modification 1 of the present disclosure. Figure 17 is a diagram illustrating another example of the configuration of a liquid crystal element according to Modification 1 of the present disclosure. Figure 18 is a diagram illustrating another example of the configuration of a liquid crystal element according to Modification 1 of the present disclosure. Figure 19 is a diagram illustrating another example of the configuration of a liquid crystal element according to Modification 1 of the present disclosure. Figure 20 is a diagram illustrating an example of the configuration of a liquid crystal element according to Modification 2 of the present disclosure.Figure 21 is a diagram illustrating another configuration example of a liquid crystal element according to Modification 2 of this disclosure. Figure 22 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 3 of this disclosure. Figure 23 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 3 of this disclosure. Figure 24 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 4 of this disclosure. Figure 25 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 4 of this disclosure. Figure 26 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 4 of this disclosure. Figure 27 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 5 of this disclosure. Figure 28 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 5 of this disclosure. Figure 29 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 6 of this disclosure. Figure 30 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 6 of this disclosure. Figure 31 is a diagram illustrating an example of operation of a liquid crystal element according to Modification 6 of this disclosure.

[0008] The embodiments of this disclosure will be described in detail below with reference to the drawings. The description will be in the following order: 1. Embodiment 2. Modifications 2-1. Modification 1 2-2. Modification 2 2-3. Modification 3 2-4. Modification 4 2-5. Modification 5 2-6. Modification 6

[0009] <1. Embodiments> Figure 1 is a diagram showing an example of a schematic configuration of a spatial light modulation device according to an embodiment of the present disclosure. The spatial light modulation device 1 is a device capable of modulating light. The spatial light modulation device 1 is configured to be able to control the phase of light using liquid crystal elements. The spatial light modulation device 1 is a spatial light modulator (SLM), and can arbitrarily control the phase of light.

[0010] The spatial light modulator 1 is a phase modulator, and is configured, for example, as a liquid crystal spatial light phase modulator. As an example, the spatial light modulator 1 is a spatial light modulator using LCOS (Liquid crystal on silicon). The spatial light modulator 1 is configured to control the wavefront of light and output any patterned light. The spatial light modulator 1 is applicable to various display devices and optical devices.

[0011] The spatial light modulator 1 can be applied, for example, to a display (e.g., a 3D display device). The spatial light modulator 1 can be applied to projectors, HUDs (Head-Up Displays), etc. The spatial light modulator 1 can be used, for example, as an optical element (optical device) such as a diffraction grating. The spatial light modulator and liquid crystal element according to this disclosure can be applied to various devices having a light modulation function.

[0012] As shown in Figure 1, the spatial light modulation device 1 includes a liquid crystal element 100 and a control unit 200. The control unit 200 is a control circuit and includes, for example, a signal processing unit 210 and a drive unit 220. The signal processing unit 210 is a signal processing circuit and is configured to perform signal processing. The signal processing unit 210 includes, for example, a processor and memory (ROM, RAM, etc.) and is configured to perform various signal processing. The signal processing unit 210 can read and execute internally embedded programs and perform signal processing (information processing).

[0013] The signal processing unit 210 also functions as a control unit (control circuit) and is configured to control each part of the spatial light modulation device 1. For example, the signal processing unit 210 is configured to supply a signal to the drive unit 220 to control the drive unit 220, thereby controlling the drive unit 220. The signal processing unit 210 can control the operation of the liquid crystal element 100 via the drive unit 220. The control unit 200 (or signal processing unit 210) may also be configured to control the light source 230.

[0014] The signal processing unit 210 is configured to generate data relating to the amount of phase modulation (referred to as phase distribution data). The signal processing unit 210 is configured to generate, for example, data relating to the amount of phase modulation for each pixel or for multiple pixels of the liquid crystal element 100 as phase distribution data. The phase distribution data is data relating to the distribution of the amount of phase modulation set for the liquid crystal element 100.

[0015] Phase distribution data (i.e., phase distribution information) is also referred to as a phase pattern, hologram pattern, or diffraction pattern, for example. In particular, a hologram pattern calculated by a computer is also called a CGH (Computer generated hologram).

[0016] The signal processing unit 210 is configured to generate phase distribution data, for example, data relating to the magnitude of the voltage (potential difference) supplied between the electrodes of each pixel of the liquid crystal element 100. The signal processing unit 210 generates the phase distribution data, for example, by performing optical propagation calculations. The signal processing unit 210 can also be described as a data processing unit (processing circuit) configured to perform data processing.

[0017] The signal processing unit 210 may, for example, generate phase distribution data relating to the phase modulation amount for each pixel and output the generated phase distribution data to the drive unit 220. Alternatively, the phase distribution data may be generated in the spatial light modulation device 1, or the signal processing unit 210 may acquire phase distribution data generated by an external device.

[0018] The liquid crystal element 100 is configured to modulate the phase of incident light. The liquid crystal element 100 is a phase modulation element and uses liquid crystal to control the phase of light from the light source 230. The liquid crystal element 100 is configured as a liquid crystal panel and has, for example, a pixel section 110 containing a plurality of pixels. The liquid crystal element 100 is, for example, a reflective liquid crystal element. However, the liquid crystal element 100 may be a transmissive liquid crystal element. The liquid crystal element 100 may be, for example, an LCOS panel.

[0019] The drive unit 220 is configured to drive the liquid crystal element 100 (i.e., the phase modulation element). The drive unit 220 is a drive circuit and is configured to drive each pixel of the pixel section 110 of the liquid crystal element 100. The drive unit 220 is composed of multiple circuits, such as a DA conversion circuit (DAC: Digital to Analog Converter) and an amplifier circuit, and can control the operation of the liquid crystal element 100.

[0020] The drive unit 220 is configured to control, for example, the voltage supplied to each pixel of the pixel unit 110. As an example, the drive unit 220 is configured to supply a voltage to drive the pixels to the liquid crystal elements 100 and to control the phase modulation by each pixel of the liquid crystal elements 100. The drive unit 220 can also be described as a control unit (or element control unit) configured to control the liquid crystal elements 100. The drive unit 220 may be configured integrally with the liquid crystal elements 100.

[0021] For example, phase distribution data is input to the drive unit 220 from the signal processing unit 210. Based on the phase distribution data, the drive unit 220 sets the magnitude (value) of the voltage to be supplied to each pixel of the liquid crystal element 100 and supplies the voltage to each pixel of the liquid crystal element 100. For example, the drive unit 220 can control the voltage supplied to each pixel of the liquid crystal element 100 so that the phase modulation amount distribution shown by the phase distribution data is obtained, and adjust the amount of phase modulation at each pixel.

[0022] The light source 230 is configured to irradiate the liquid crystal element 100 with light. The light source 230 is configured, for example, using a plurality of light-emitting elements. The light-emitting elements are, for example, LDs (Laser Diodes) and LEDs (Light Emitting Diodes), and can output light to the outside. As an example, the light source 230 is configured to generate laser light and emit laser light to the outside.

[0023] The light source 230 may be configured using a semiconductor laser element, such as a vertical cavity surface-emitting laser (VCSEL). The spatial light modulation device 1 can control the wavefront of the light by, for example, refracting or diffracting the light from the light source 230 using a liquid crystal element 100. The spatial light modulation device 1 may include the light source 230.

[0024] Figure 2 shows an example of the pixel portion of a liquid crystal element according to an embodiment. The liquid crystal element 100 has a region (pixel portion 110) where a plurality of pixels P are provided, as shown in the example in Figure 2. In the liquid crystal element 100, for example, a plurality of pixels P are provided in the pixel portion 110 so as to be aligned in the horizontal direction (X-axis direction) and the vertical direction (Y-axis direction).

[0025] Multiple pixels P of the liquid crystal element 100 are arranged in a two-dimensional manner in the X-axis and Y-axis directions. The liquid crystal element 100 has multiple pixels P, as shown in the example in Figure 2, and is configured so that the phase of light can be controlled for each pixel P. The number and arrangement of pixels P in the pixel section 110 of the liquid crystal element 100 are not limited to the illustrated example and can be set arbitrarily.

[0026] As shown in Figure 2, the direction of light incidence on the liquid crystal element 100 (i.e., the direction of light incidence from the light source 230) is defined as the Z-axis direction, the left-right direction on the paper perpendicular to the Z-axis direction is defined as the X-axis direction, and the up-down direction on the paper perpendicular to both the Z-axis and X-axis directions is defined as the Y-axis direction. In subsequent figures, directions may also be indicated based on the direction of the arrows in Figure 2.

[0027] Figure 3 shows an example of a schematic configuration of a liquid crystal element according to an embodiment. The liquid crystal element 100 has a substrate 101, a liquid crystal layer 120, and a substrate 102, as schematically shown in Figure 3. The liquid crystal layer 120 also has an optical layer 130. The optical layer 130 is a layer having a plurality of structures 50 and is provided between the substrate 101 and the substrate 102.

[0028] The optical layer 130 is an optical component utilizing metamaterial (metasurface) technology and is provided to be laminated on the substrate 101 (or substrate 102). The structure 50 is, for example, a columnar structure. As an example, the structure 50 is a pillar (columnar member) having a cylindrical shape.

[0029] The structure 50 is constructed, for example, using a dielectric material having a refractive index different from that of the surrounding material. The structure 50 is referred to as, for example, a dielectric pillar. The structure 50 is also referred to as a nanopillar, nanodisk, nanostructure, or microstructure. The number and arrangement of the structures 50 are not limited to the illustrated example and can be set arbitrarily.

[0030] The liquid crystal element 100 has an optical layer 130 containing a plurality of structures 50, and is configured to modulate incident light by the liquid crystal layer 120 and the optical layer 130. The liquid crystal element 100 has a liquid crystal metasurface structure and can also be called a liquid crystal metasurface element. The shape of each structure 50 in the optical layer 130 is not limited to the illustrated example and can be changed as appropriate. For example, the structure 50 may have a circular, elliptical, or polygonal shape in a plan view (i.e., when viewed in the XY plane).

[0031] Figure 4 shows an example of a planar configuration of a liquid crystal element according to an embodiment. The liquid crystal element 100 has a region (referred to as the effective region 60) configured to modulate light in a specific wavelength band. The effective region 60 corresponds to one region when the liquid crystal element 100 (or pixel portion 110) is spatially divided into multiple regions.

[0032] The effective region 60 is an area that can be used for displaying (reproducing) an image (e.g., a holographic image), and is configured to be able to modulate the phase of the incident light. The liquid crystal element 100 has a plurality of effective regions 60 (effective region 60r, effective region 60g, and effective region 60b in Figure 4), for example, as shown in Figure 4.

[0033] The effective region 60r is, for example, a region capable of modulating light in the red (R) wavelength range, and the effective region 60g is a region capable of modulating light in the green (G) wavelength range. The effective regions 60r and 60g are located adjacent to each other in the X-axis direction, for example. The effective region 60b is a region capable of modulating light in the blue (B) wavelength range. The effective regions 60g and 60b are located adjacent to each other in the X-axis direction.

[0034] The effective regions 60r, 60g, and 60b are, for example, regions that divide the pixel portion 110 into approximately equal parts and are located adjacent to each other. Each of the effective regions 60r, 60g, and 60b has a size that, for example, divides the pixel portion 110 into approximately three equal parts. The number and arrangement of each of the effective regions 60r, 60g, and 60b are not limited to the illustrated example and can be changed as appropriate.

[0035] The effective regions 60r, 60g, and 60b may be provided with the aforementioned minute structures 50 (see also Figure 3). For example, multiple structures 50 (i.e., nanopillars) may be arranged in each of the effective regions 60r, 60g, and 60b. Alternatively, the structures 50 may be provided in only one or two of the effective regions 60r, 60g, and 60b.

[0036] The light source 230 (see Figure 1) of the spatial light modulation device 1 is configured to emit, for example, red (R) light, green (G) light, and blue (B) light. The light source 230 is, as an example, configured as an RGB laser light source. The light source 230 can, for example, output light in the red wavelength range to the effective region 60r of the liquid crystal element 100, light in the green wavelength range to the effective region 60g of the liquid crystal element 100, and light in the blue wavelength range to the effective region 60b of the liquid crystal element 100. The light source 230 may also be configured using an LED or a phosphor.

[0037] The spatial light modulation device 1 has an optical system 240, for example, as shown in the example in Figure 5. The optical system 240 is configured, for example, using a collimator lens, and is configured to guide light of each wavelength from the light source 230 to different regions of the liquid crystal element 100. As an example, the optical system 240 can irradiate (illuminate) the effective regions 60r, 60g, and 60b with RGB light from the light source 230. The light source 230 may also be configured to include the optical system 240.

[0038] Figures 6 and 7 are diagrams illustrating an example of the configuration of a liquid crystal element according to an embodiment. Figure 6 schematically shows an example of the cross-sectional configuration in the effective region 60r, effective region 60g, and effective region 60b. Figure 7 shows an example of the planar configuration of the optical layer 130 of the liquid crystal element 100.

[0039] Although only three pixels P are shown in Figure 6, the effective regions 60r, 60g, and 60b may each have multiple pixels P. Furthermore, the three white arrows in Figure 6 schematically represent the incident light from the light source 230: red light, green light, and blue light, respectively.

[0040] The liquid crystal element 100 includes a substrate 101, a liquid crystal layer 120, an optical layer 130, and a substrate 102. The liquid crystal element 100 has a structure in which the substrate 101, the liquid crystal layer 120, the optical layer 130, and the substrate 102 are laminated in the Z-axis direction. For example, the substrate 101, the liquid crystal layer 120, the optical layer 130, and the substrate 102 are provided in this order from the side where light is incident.

[0041] The substrates 101 and 102 are arranged to face each other. The substrate 101 and the substrate 102 are fixed by a sealing material (not shown) with the liquid crystal layer 120 and the optical layer 130 interposed therebetween, for example. The substrate 101 and the substrate 102 are arranged apart from each other in the thickness direction of the liquid crystal layer 120, that is, the stacking direction (Z-axis direction in FIG. 6).

[0042] The substrate 101 is a substrate that transmits light (transparent substrate), and is constituted by, for example, a glass substrate. The substrate 101 (base material) is constituted by, for example, quartz glass, borosilicate glass, or the like. An electrode 20 is provided on the substrate 101. Note that the substrate 101 may be constituted by using other materials that transmit incident light.

[0043] The substrate 102 is a substrate configured as a support substrate, and is constituted by a semiconductor substrate (for example, a silicon substrate), a glass substrate, or the like. An electrode 30 is provided on the substrate 102. In the liquid crystal element 100, the electrode 20 and the electrode 30 are arranged so as to sandwich the liquid crystal layer 120 and the optical layer 130.

[0044] The electrode 20 is arranged to face the electrode 30 while sandwiching a part of each of the liquid crystal layer 120 and the optical layer 130. The electrode 20 is, for example, an electrode common to a plurality of pixels P, and is provided on one surface side of the substrate 101. The electrode 20 can be referred to as a counter electrode or a common electrode. The electrode 20 is provided on the substrate 101, for example, between the substrate 101 and the liquid crystal layer 120.

[0045] The electrode 20 (that is, the counter electrode) is a transparent electrode, and is constituted by, for example, ITO (indium tin oxide). Also, for example, the electrode 20 may be constituted by IZO (indium zinc oxide). Note that the electrode 20 may be constituted by using other tin oxide-based materials, zinc oxide-based materials, or the like, or may be constituted by using other transparent conductive materials.

[0046] The electrode 30 is an electrode provided for each pixel P and is provided on one surface side of the substrate 102. The electrode 30 can be said to be a pixel electrode. The electrode 30 (i.e., the pixel electrode) is configured as a transparent electrode using a transparent conductive material (transparent conductive film) such as ITO, IZO, etc. Note that the electrode 30 may be formed using a material that reflects light. The electrode 30 may be composed of, for example, a metal material such as aluminum (Al), copper (Cu), etc.

[0047] The electrodes 20 and 30 are electrically connected to a circuit, a terminal, etc. provided on the substrate 102 via, for example, different wirings, pads, etc. respectively. Circuit elements such as transistors, capacitor elements, resistor elements, etc. for driving each pixel P and wirings (signal lines, power supply lines, etc.) can be formed on the substrate 102.

[0048] The liquid crystal layer 120 is a layer containing a plurality of liquid crystal molecules 15 and is provided between the substrate 101 and the substrate 102. The liquid crystal layer 120 is sealed between the substrate 101 and the substrate 102 by, for example, a sealing material. In the liquid crystal element 100, when a voltage is supplied (applied) between the electrodes 20 and 30, the liquid crystal molecules 15 in the liquid crystal layer 120 respond, and the alignment of the liquid crystal molecules 15 is controlled.

[0049] The liquid crystal element 100 has, for example, an alignment film 40a and an alignment film 40b as shown in the example of FIG. 6. The alignment film 40a and the alignment film 40b are provided with respect to the liquid crystal layer 120. The alignment film 40a is provided between the liquid crystal layer 120 and the electrode 20. Also, the alignment film 40b is provided between the liquid crystal layer 120 and the electrode 30.

[0050] In the example shown in FIG. 6, the alignment film 40a is formed on the electrode 20 between the substrate 101 and the substrate 102 and is located between the liquid crystal layer 120 and the electrode 20. Also, the alignment film 40b is formed on the electrode 30 between the substrate 101 and the substrate 102. A part of the alignment film 40b is located between the liquid crystal layer 120 and the electrode 30.

[0051] The orientation films 40a and 40b are each composed of, for example, organic materials. The orientation films 40a and 40b may be composed of polyimide films that have undergone rubbing treatment (i.e., orientation treatment). Alternatively, the orientation films 40a and 40b may be composed of inorganic materials. Each of the orientation films 40a and 40b may be, for example, a film formed by oblique deposition of silicon oxide (i.e., an obliquely deposited film).

[0052] Alignment films 40a and 40b can align the liquid crystal molecules 15 of the liquid crystal layer 120 in a specific direction. The liquid crystal molecules 15 of the liquid crystal layer 120 are held in a tilted state by the alignment films 40a and 40b. That is, a predetermined pre-tilt angle (i.e., tilt angle) is imparted to the liquid crystal molecules 15 of the liquid crystal layer 120. Alignment films 40a and 40b can also be described as films (layers) that can control the orientation of the liquid crystal molecules 15.

[0053] The optical layer 130 has structures 50 as nanostructures and is configured to modulate incident light. The optical layer 130 has a plurality of structures 50 arranged in the X-axis direction (or Y-axis direction), as shown in the example in Figures 6 and 7. The structures 50 have a cylindrical shape, for example. The optical layer 130 can also be called a metasurface layer.

[0054] The optical layer 130 is provided, for example, between the liquid crystal layer 120 and the substrate 102. The optical layer 130, which includes a plurality of structures 50, is provided so as to be stacked on the substrate 102. In the liquid crystal element 100, for example, one or more structures 50 are provided for each electrode 30 of the pixel P in the effective regions 60r, 60g, and 60b.

[0055] The optical layer 130 includes, for example, a structure 50 (structure 50r) provided in the effective region 60r, a structure 50 (structure 50g) provided in the effective region 60g, and a structure 50 (structure 50b) provided in the effective region 60b, as shown in the examples in Figures 6 and 7. Light from the light source 230 is incident on each structure 50 in the effective region 60, for example, via the substrate 101.

[0056] The structures 50 (structures 50r, 50g, and 50b in Figures 6 and 7) have a size that is less than or equal to a predetermined wavelength of incident light. For example, the width of the structure 50 in the X-axis direction (or Y-axis direction) may be less than or equal to the wavelength range of the light to be modulated, for example, less than or equal to the wavelength range of visible light. Also, the length (height) of the structure 50 in the stacking direction (i.e., the Z-axis direction) may be less than or equal to the wavelength range of visible light.

[0057] In the example shown in Figure 6, the structure 50 is provided within the alignment film 40b. The multiple structures 50 in each effective region 60 are arranged so as to be aligned with each other in the X-axis or Y-axis direction, with a portion of the alignment film 40b in between, for each electrode 30 (i.e., each pixel P). The alignment film 40b is formed, for example, to cover the multiple structures 50. A portion of the alignment film 40b is provided between adjacent multiple structures 50.

[0058] In each effective region 60 (effective regions 60r, 60g, 60b), multiple structures 50 are arranged at intervals of less than or equal to a predetermined wavelength of incident light, as shown in the example in Figure 7. As an example, multiple structures 50 are provided in the X-axis and Y-axis directions at intervals of less than or equal to the wavelength range of visible light. Note that structures 50 may be arranged in only one or two of the effective regions 60 60r, 60g, and 60b.

[0059] The structure 50 is configured to have a refractive index different from that of the surrounding material. The structure 50 has a refractive index different from that of the surrounding members, for example, the alignment film 40b. For example, the structure 50 has a refractive index higher than that of the alignment film 40b. Also, for example, the structure 50 may have a refractive index higher than that of the liquid crystal molecules 15 of the liquid crystal layer 120.

[0060] The structure 50 is composed of, for example, an oxide film containing titanium (Ti). As an example, the structure 50 is composed of titanium oxide (TiO). Other examples include the use of silicon, polysilicon (Poly-Si), amorphous silicon (a-Si), silicon nitride (SiN), silicon oxide (SiO), etc.

[0061] The structure 50 may be composed of elements, oxides, nitrides, oxynitrides, or composites thereof of titanium (Ti), hafnium (Hf), aluminum (Al), zirconium (Zr), zinc (Zn), magnesium (Mg), etc. The structure 50 may be composed of metal compounds (metal oxides, metal nitrides, etc.) or of non-metallic materials (non-metallic nitrides, non-metallic sulfides, etc.).

[0062] Furthermore, the liquid crystal element 100 is configured such that the size (width, length, etc.) of the structure 50 differs in each effective region 60. For example, the liquid crystal element 100 is configured such that the size of the structure 50r in the effective region 60r, the size of the structure 50g in the effective region 60g, and the size of the structure 50b in the effective region 60b are different.

[0063] In the liquid crystal element 100, for example, the width of the structure 50r in the X-axis direction (or Y-axis direction) is set to a size smaller than or equal to the wavelength range of red, and the width of the structure 50g in the X-axis direction (or Y-axis direction) is set to a size smaller than or equal to the wavelength range of green. Also, the width of the structure 50b in the X-axis direction (or Y-axis direction) is set to a size smaller than or equal to the wavelength range of blue.

[0064] Furthermore, in the liquid crystal element 100, for example, the height (length) of the structure 50r in the Z-axis direction is set to a size below the wavelength range of red, and the height of the structure 50g in the Z-axis direction is set to a size below the wavelength range of green. Also, the height of the structure 50b in the Z-axis direction is set to a size below the wavelength range of blue.

[0065] In the liquid crystal element 100, the material of the structure 50 (optical constants of the material (refractive index, extinction coefficient)), the size of the structure 50 (width, height, etc.), the pitch (arrangement interval), and the number of structures are determined so that the range of phase modulation amounts that can be set in each effective region 60 is within a desired range. The width and height of each of the structures 50r, 50g, and 50b can be selected according to the wavelength band of the incident light to be modulated.

[0066] The liquid crystal element 100 is configured such that, for example, as shown in Figure 8, the width w2 of the structure 50g in the effective area 60g is smaller than the width w1 of the structure 50r in the effective area 60r. As shown in Figure 9, for example, the radius r2 of the cylindrical structure 50g may be smaller (narrower) than the radius r1 of the cylindrical structure 50r.

[0067] Furthermore, as shown in the example in Figure 8, the liquid crystal element 100 is configured such that the width w3 of the structure 50b in the effective region 60b is smaller than the width w2 of the structure 50g in the effective region 60g. As shown in Figure 9, for example, the radius r3 of the cylindrical structure 50b may be set to be smaller than the radius r2 of the cylindrical structure 50g.

[0068] For example, the width w1 of structure 50r may be in the range of 240 nm to 280 nm (for example, 260 nm). The width w2 of structure 50g may be in the range of 190 nm to 230 nm (for example, 210 nm). Also, the width w3 of structure 50b may be in the range of 160 nm to 200 nm (for example, 180 nm).

[0069] As an example, the radius r1 of structure 50r may be in the range of 110 nm to 150 nm (for example, 130 nm). The radius r2 of structure 50g may be in the range of 90 nm to 120 nm (for example, 105 nm). Also, the radius r3 of structure 50b may be in the range of 70 nm to 110 nm (for example, 90 nm).

[0070] Furthermore, as shown in Figure 10, the liquid crystal element 100 is configured such that, for example, the height d2 of the structure 50g (i.e., the length of the structure 50g in the Z-axis direction) is smaller than the height d1 of the structure 50r. Also, in the example shown in Figure 10, the height d3 of the structure 50b is made smaller than the height d2 of the structure 50g.

[0071] For example, the height d1 of structure 50r may be in the range of 200 nm to 240 nm (for example, 220 nm). The height d2 of structure 50g may be in the range of 160 nm to 200 nm (for example, 180 nm). Also, the height d3 of structure 50b may be in the range of 130 nm to 170 nm (for example, 150 nm).

[0072] As described above, the liquid crystal element 100 has a liquid crystal layer 120 and an optical layer 130 including a structure 50. In the liquid crystal element 100, the electric field in the liquid crystal layer 120 changes in response to the voltage supplied between the electrode 20 and the electrode 30, and the orientation of the liquid crystal molecules 15 changes. By controlling the voltage supplied to the electrode 30 of each pixel P, the orientation of the liquid crystal molecules 15 can be adjusted for each pixel P, changing the refractive index and thus changing the resonance conditions of the structure 50 as a nanostructure.

[0073] Light incident on each pixel P of the liquid crystal element 100 is phase-modulated according to, for example, the tilt amount of the liquid crystal molecules 15 of each pixel P and the resonant frequency before being emitted. By utilizing the large phase change amount near the resonant frequency, the liquid crystal element 100 can generate different phase delays for each pixel P relative to the incident light, thereby enabling the propagation of light with a desired wavefront.

[0074] In this embodiment, the liquid crystal element 100 is configured as a liquid crystal metasurface element, and optical modulation can be performed by the liquid crystal element 100 and the optical layer 130. This makes it possible to narrow the gap of the liquid crystal layer 120. Furthermore, it becomes possible to use any liquid crystal material. By narrowing the cell gap (thickness of the liquid crystal layer), crosstalk between pixels P can be suppressed, and the image quality can be improved.

[0075] Furthermore, narrowing the gap of the liquid crystal layer 120 can improve the response performance of the liquid crystal element 100. The liquid crystal layer 120 does not need to have an extremely high Δn (refractive index anisotropy), and any liquid crystal material can be selected, so for example, the reliability of the liquid crystal element 100 (and the spatial light modulation device 1) can be improved, and the effective potential can also be tuned.

[0076] As described above, the liquid crystal element 100 according to this embodiment has a plurality of effective regions 60. The liquid crystal element 100 is configured such that the size of the structure 50 in each effective region 60 is different. For this reason, for example, nanostructures corresponding to the wavelength range of the light to be modulated can be arranged in each effective region 60 to optimize the resonance for each wavelength range.

[0077] In the liquid crystal element 100, structures 50r, 50g, and 50b having different widths and heights are provided for the effective regions 60r, 60g, and 60b, allowing for appropriate setting of the phase modulation range in each of the effective regions 60r, 60g, and 60b. This makes it possible to realize a liquid crystal element 100 and a spatial light modulator 1 that are compatible with color display.

[0078] The drive unit 220 of the spatial light modulation device 1 controls the voltage applied to each pixel in the effective regions 60r, 60g, and 60b of the liquid crystal element 100 based on phase distribution data generated separately for each color (i.e., for each effective region 60) by the signal processing unit 210. In the liquid crystal element 100, at predetermined time intervals (e.g., each frame), the rotation angle of the liquid crystal molecules 15 in each pixel changes according to the input voltage, and the phase of the light incident on the liquid crystal layer 120 and the optical layer 130 is modulated.

[0079] In the liquid crystal element 100, the voltage at each pixel in the effective regions 60r, 60g, and 60b is adjusted to provide a desired phase distribution (i.e., spatial phase distribution) with respect to the incident light (e.g., red light, green light, and blue light), thereby performing phase control and amplitude control. The spatial light modulator 1 can dynamically and efficiently control the phase of light in each wavelength range, enabling the display of any desired color.

[0080] Figures 11 and 12 are diagrams illustrating an example of the configuration of a liquid crystal element according to an embodiment. The liquid crystal element 100 may have regions (referred to as boundary regions) located between a plurality of adjacent effective regions 60. For example, the liquid crystal element 100 has boundary regions 71 and 72. Boundary regions 71 and 72 are provided at the boundaries of a plurality of effective regions 60 divided according to wavelength range in the pixel portion 110.

[0081] The boundary region 71 is provided between the effective region 60r and the effective region 60g, as shown in the example in Figure 11. The boundary region 72 is provided between the effective region 60g and the effective region 60b. The optical layer 130 of the liquid crystal element 100 has effective regions 60r, 60g, and 60b, and boundary regions 71 and 72.

[0082] Boundary regions 71 and 72 are configured, for example, as regions without structures 50 (unformed regions). In the example shown in Figure 12, no structures 50r and 50g are provided in boundary region 71 between effective region 60r and effective region 60g. Similarly, no structures 50g and 50b are provided in boundary region 72 between effective region 60g and effective region 60b.

[0083] In the liquid crystal element 100, the provision of boundary regions 71 and 72 makes it possible to improve image quality. Compared to a case where the liquid crystal element 100 does not have boundary regions 71 and 72, wavefront disturbances between the effective regions 60 are suppressed, and deterioration of image quality (for example, the image becoming darker) caused by a decrease in diffraction efficiency can be suppressed.

[0084] By configuring the liquid crystal element 100 to have boundary regions 71 and 72, light leakage into the surrounding effective region 60 can be suppressed. Furthermore, the occurrence of unwanted resonance modes can be suppressed. This makes it possible to improve the image quality of the reproduced image. Note that the liquid crystal element 100 may have only one of the boundary regions 71 and 72.

[0085] Figure 13 is a diagram illustrating an example of the configuration of a liquid crystal element according to an embodiment. The liquid crystal element 100 may have a plurality of liquid crystal layers 120 (in Figure 13, liquid crystal layer 120a, liquid crystal layer 120b, and liquid crystal layer 120c) as the liquid crystal layer 120 described above. Liquid crystal layer 120a, liquid crystal layer 120b, and liquid crystal layer 120c are configured, for example, to have different liquid crystal materials.

[0086] In the example shown in Figure 13, the liquid crystal layer 120a is provided in the effective region 60r. For example, the liquid crystal layer 120a is formed by injecting liquid crystal material through the injection port 91a. The liquid crystal layer 120a and the injection port 91a are sealed (closed) by a sealing material 90 (for example, resin) acting as a partition member.

[0087] The liquid crystal layer 120b is provided over the effective area 60g. For example, the liquid crystal layer 120b is formed by injecting liquid crystal material through the injection port 91b. As an example, the liquid crystal layer 120b is made using a different liquid crystal material than the liquid crystal material that constitutes the liquid crystal layer 120a. The liquid crystal layer 120b and the injection port 91b are sealed by a sealing material 90 (resin) acting as a partition member.

[0088] Furthermore, the liquid crystal layer 120c is provided in the effective region 60b. For example, the liquid crystal layer 120c is formed by injecting liquid crystal material through the injection port 91c. The liquid crystal layer 120c may be constructed using a different liquid crystal material than that used for liquid crystal layers 120a and 120b. The liquid crystal layer 120c and the injection port 91c are sealed by a sealing material 90 acting as a partition member.

[0089] Each of the liquid crystal materials in the liquid crystal layers 120a, 120b, and 120c is selected according to the wavelength range of the incident light to be modulated, light resistance, etc. Therefore, for example, the amount of phase modulation in the effective regions 60r, 60g, and 60b can be increased. Furthermore, the reliability of the liquid crystal element 100 can be improved.

[0090] Figure 14 is a diagram illustrating another example of the configuration of the liquid crystal element according to the embodiment. The liquid crystal element 100 may have a configuration having only one or two of the liquid crystal layers 120a, 120b, and 120c. In the example shown in Figure 14, the liquid crystal layer 120a is provided for the effective region 60r and the effective region 60g. The liquid crystal layer 120c is provided for the effective region 60b. The liquid crystal layers 120a and 120c are, for example, made using different liquid crystal materials.

[0091] Figures 15A to 15F illustrate an example of a method for manufacturing the optical layer of a liquid crystal element according to an embodiment. As shown in Figure 15A, electrodes 30 are formed on a substrate 102. Then, as shown in Figure 15B, a resist film 80 is formed on the electrodes 30 on the substrate 102. Furthermore, as shown in Figure 15C, the resist film 80 is patterned by lithography and etching.

[0092] Next, as shown in Figure 15D, the member 55 is formed by Atomic Vapor Deposition (ALD). For example, the member 55 is formed from a dielectric material. Then, as shown in Figure 15E, a portion of the member 55 is removed by etching (for example, plasma etching) so that the upper surface (surface) of the structure 50 is exposed.

[0093] Next, the resist film 80 is removed by etching, forming the structure 50 as shown in Figure 15F. The optical layer 130 shown in Figure 6, etc., can be manufactured using the above manufacturing method. Note that the above-described manufacturing method is merely an example, and other manufacturing methods may be employed.

[0094] [Function and Effects] The liquid crystal element according to this embodiment comprises a first substrate (substrate 102) having a first electrode (electrode 30) provided on each of a plurality of pixels (pixels P), a second substrate (substrate 101) having a second electrode (electrode 20) provided opposite to the first electrode, a liquid crystal layer (liquid crystal layer 120) provided between the first substrate and the second substrate, and an optical layer (optical layer 130) provided between the first substrate and the second substrate and having a first region and a second region (for example, effective regions 60r, 60g). The first region has a first structure (for example, structure 50r) having a columnar shape. The optical layer is capable of modulating light in a first wavelength range incident on the first region and is capable of modulating light in a second wavelength range incident on the second region.

[0095] The liquid crystal element 100 according to this embodiment includes an optical layer 130 having an effective region 60r and an effective region 60g. The effective region 60r has a structure 50r. The optical layer 130 can modulate light in the red wavelength range incident on the effective region 60r and can modulate light in the green wavelength range incident on the effective region 60g. Therefore, it is possible to realize a liquid crystal element that is advantageous for high image quality.

[0096] Next, modified examples of the present disclosure will be described. In the following, components similar to those in the embodiments described above will be denoted by the same reference numerals, and their descriptions will be omitted as appropriate.

[0097] <2. Modifications> (2-1. Modification 1) In the embodiments described above, examples of liquid crystal element configurations have been explained, but the configuration of the liquid crystal element is not limited to the examples described above. Figure 16 is a diagram illustrating an example of liquid crystal element configuration according to Modification 1 of this disclosure. As shown in the example in Figure 16, structures 51 may be provided in the boundary regions 71 and 72 of the liquid crystal element 100.

[0098] Structure 51 is positioned as a dummy structure in boundary region 71 or boundary region 72. Structure 51 is made of the same material as structure 50, for example, and has a columnar shape. Structure 51 can also be called a dummy pillar or a dielectric dummy pillar. Note that structure 51 may be made of a different material than structure 50.

[0099] In boundary regions 71 and 72, for example, a plurality of structures 51 are configured to be arranged in the Y-axis direction. The structures 51 have, for example, a cylindrical shape. The shape of the structures 51 in plan view (i.e., when viewed in the XY plane) may be circular, elliptical, or polygonal.

[0100] Structure 51 has a different size from the surrounding structures 50 (structure 50r, structure 50g, or structure 50b), and is configured not to resonate with light in the wavelength range to be modulated, such as light in the visible light wavelength range. Structure 50 and structure 51 as a dummy structure are, for example, both placed in the optical layer 130 and have different widths and heights.

[0101] For example, the width of structure 51 in the X-axis direction (or Y-axis direction) may be greater than the width of structure 50 in the X-axis direction (or Y-axis direction). As an example, the radius of cylindrical structure 51 may be greater than the radius of cylindrical structure 50. Also, the height (length) of structure 51 in the Z-axis direction may be greater than the height of structure 50 in the Z-axis direction.

[0102] The width of the structure 51 in the X-axis direction (or Y-axis direction) may be, for example, within the range of 600 nm to 640 nm (e.g., 620 nm). The radius of the structure 51 may be within the range of 285 nm to 325 nm (e.g., 305 nm). The height of the structure 51 may be within the range of 495 nm to 535 nm (e.g., 515 nm).

[0103] Figure 17 is a diagram illustrating another example of the configuration of the liquid crystal element according to Modification 1. The liquid crystal element 100 may be configured to have different dummy structures in the boundary region 71 and the boundary region 72. In the example shown in Figure 17, structure 51 is provided for the boundary region 71, and structure 52 is provided for the boundary region 72.

[0104] Structure 52 is configured, for example, as a dummy structure (i.e., a dummy pillar), to have a different size (width, radius, height, etc.) from structure 51. Structures 51 and 52 may be made of the same material or different materials. In this modified case as well, the same effects as in the above-described embodiment can be obtained.

[0105] Figures 18 and 19 are diagrams illustrating another configuration example of the liquid crystal element according to Modification 1. Boundary regions 71 and 72 may each have multiple types of dummy structures. Boundary region 71 is provided with, for example, structures 51a and 51b having different sizes from each other.

[0106] Furthermore, structures 52a and 52b having different sizes may be provided in the boundary region 72. As shown in the example in Figure 18, structures 51a and 51b may be mixed and arranged in the boundary region 71. Also, in the boundary region 72, structures 52a and 52b may be mixed and arranged.

[0107] As shown in the example in Figure 18, the effective region 60g, which can modulate green wavelength light, a highly visible color, may be provided in the right (or left) region of the pixel section 110, rather than in the central region. In the example shown in Figure 18, the effective region 60b is provided in the central region of the pixel section 110 and is located between the effective region 60r and the effective region 60g. By configuring the liquid crystal element 100 as shown in the example in Figure 18, it is expected that image quality will be improved.

[0108] As shown in the example in Figure 19, a dummy structure may not be provided in one of the boundary regions, for example, boundary region 72. In the example shown in Figure 19, boundary region 72 is a region without structures 52a and 52b, and is configured as an unformed region. Alternatively, structures 52a and 52b may be placed in boundary region 72, while structures 51a and 51b may not be placed in boundary region 71.

[0109] (2-2. Modification 2) Figure 20 is a diagram illustrating an example of the configuration of a liquid crystal element according to Modification 2. The optical layer 130 may be provided between the liquid crystal layer 120 and the substrate 101, as shown in the example in Figure 20. The optical layer 130 includes a plurality of structures 50 and is provided to be stacked on the substrate 101. In the example shown in Figure 20, the structures 50 (50r, 50g, 50b) of each effective region 60 are provided within the alignment film 40a.

[0110] The multiple structures 50 in each effective region 60 are arranged, for example, on the electrodes 20 of the substrate 101, so as to be aligned with each other in the X-axis direction or the Y-axis direction, with a portion of the alignment film 40a in between. The alignment film 40a is provided, for example, so as to cover the multiple structures 50. A portion of the alignment film 40a is provided between adjacent multiple structures 50.

[0111] Figure 21 is a diagram illustrating another configuration example of a liquid crystal element according to Modification 2. One or two of the effective regions 60r, 60g, and 60b may be provided on the substrate 101 side. For example, each structure 50g of the central effective region 60g is arranged on the substrate 101 side and is located between the liquid crystal layer 120 and the substrate 101.

[0112] In the example shown in Figure 21, the liquid crystal element 100 has an optical layer 130 consisting of an optical layer 130a having a structure 50g and an optical layer 130b having structures 50r and 50b. Optical layer 130a is provided on the substrate 101 side, and optical layer 130b is provided on the substrate 102 side. The structure 50r of the effective region 60r is arranged in optical layer 130b.

[0113] The structure 50g in the effective region 60g, located next to the effective region 60r, is placed in the optical layer 130a, and the structure 50b in the effective region 60b, located next to the effective region 60g, is placed in the optical layer 130b. In this case, the interaction between structure 50r and structure 50g can be reduced, and the interaction between structure 50g and structure 50b can be reduced.

[0114] (2-3. Modification 3) Figures 22 and 23 are diagrams illustrating an example of the configuration of a liquid crystal element according to Modification 3. The liquid crystal element 100 may be configured to have a plurality of effective regions 60r, a plurality of effective regions 60g, and a plurality of effective regions 60b. As shown in the example in Figure 22, the liquid crystal element 100 may have two effective regions 60r, two effective regions 60g, and two effective regions 60b.

[0115] In the liquid crystal element 100, for example, an effective region 60r, an effective region 60g, and an effective region 60b may be repeatedly provided. In the example shown in Figure 23, the liquid crystal element 100 has a region 105 in which the effective region 60r and the effective region 60g are alternately provided in the X-axis direction, and a region 106 in which the effective region 60g and the effective region 60b are alternately provided in the X-axis direction.

[0116] (2-4. Modification 4) Figure 24 is a diagram illustrating an example of the configuration of a liquid crystal element according to Modification 4. The liquid crystal element 100 may be configured such that the orientation direction of the liquid crystal molecules 15 in each effective region 60 is different. For example, the orientation processing conditions (polar angle, azimuthal angle, etc.) may be different for each effective region 60 of the liquid crystal element 100.

[0117] The liquid crystal element 100 is configured such that, for example, the orientation direction of the liquid crystal molecules 15 (liquid crystal molecules 15g) in the effective region 60g is different from the orientation direction of the liquid crystal molecules 15 (liquid crystal molecules 15r) in the effective region 60r. Furthermore, the orientation direction of the liquid crystal molecules 15g in the effective region 60g may be different from the orientation direction of the liquid crystal molecules 15 (liquid crystal molecules 15b) in the effective region 60b.

[0118] In the example shown in Figure 24, the liquid crystal element 100 is configured such that the orientation direction of the liquid crystal molecules 15g in the effective region 60g is orthogonal to the orientation direction of the liquid crystal molecules 15r in the effective region 60r (or the liquid crystal molecules 15b in the effective region 60b). By making the orientation directions orthogonal between adjacent regions, it is possible to suppress image quality degradation caused by illumination light irradiating adjacent regions.

[0119] Figures 25 and 26 are diagrams illustrating an example of the configuration of a liquid crystal element according to Modification 4. The liquid crystal element 100 may be configured such that the pre-tilt angles of the liquid crystal molecules 15 in each effective region 60 are different. As shown in Figure 25 or Figure 26, the liquid crystal layer 120 has a liquid crystal region 125r provided in relation to the effective region 60r, a liquid crystal region 125g provided in relation to the effective region 60g, and a liquid crystal region 125b provided in relation to the effective region 60b.

[0120] The liquid crystal element 100 may be configured such that the pre-tilt angle of the liquid crystal molecules 15g in the liquid crystal region 125g is greater than the pre-tilt angle of the liquid crystal molecules 15r in the liquid crystal region 125r (or the liquid crystal molecules 15b in the liquid crystal region 125b), as shown in the example in Figure 25. As shown in the example in Figure 26, the pre-tilt angle of the liquid crystal molecules 15g may be smaller than the pre-tilt angle of the liquid crystal molecules 15r and larger than the pre-tilt angle of the liquid crystal molecules 15b. By configuring the liquid crystal element 100 in this way, crosstalk can be suppressed and image quality can be improved.

[0121] (2-5. Modification 5) Figures 27 and 28 are diagrams illustrating an example of the configuration of a liquid crystal element according to Modification 5. The liquid crystal element 100 may be configured such that the thickness of the liquid crystal layer 120 differs in each effective region 60. For example, the thickness of the liquid crystal layer 120 in the Z-axis direction (i.e., the cell gap) may differ for each effective region 60 of the liquid crystal element 100.

[0122] The liquid crystal element 100 is configured such that, for example, the cell gap g1 in the effective region 60r (i.e., the thickness of the liquid crystal region 125r in the liquid crystal layer 120) and the cell gap g2 in the effective region 60g (i.e., the thickness of the liquid crystal region 125g in the liquid crystal layer 120) are different. Also, for example, the cell gap g2 in the effective region 60g and the cell gap g3 in the effective region 60b (i.e., the thickness of the liquid crystal region 125b) are different.

[0123] In the example shown in Figure 27, the liquid crystal element 100 is configured such that the cell gap g2 of the effective region 60g is larger than the cell gap g1 of the effective region 60r. Furthermore, the liquid crystal element 100 is configured such that the cell gap g3 of the effective region 60b is larger than the cell gap g2 of the effective region 60g.

[0124] The liquid crystal element 100 may be configured such that the cell gap g2 of the effective region 60g is smaller than the cell gap g1 of the effective region 60r, as shown in the example in Figure 28. Alternatively, the liquid crystal element 100 may be configured such that the cell gap g2 of the effective region 60g is smaller than the cell gap g3 of the effective region 60b.

[0125] The liquid crystal element 100 according to this modified example is configured such that the cell gap is different in each of the multiple adjacent effective regions 60. This makes it possible to suppress crosstalk and prevent deterioration of the image quality of the reproduced image. As shown in the example in Figure 28, by reducing the cell gap g2 of the effective region 60g used for wavelength modulation of green light, which is a highly visible color, image quality deterioration can be effectively suppressed.

[0126] (2-6. Modification 6) Figures 29 and 30 are diagrams illustrating an example of the configuration of a liquid crystal element according to Modification 6. Figure 29 shows an example of the relationship between the pixel pitch and the diffraction angle of light (i.e., the steering angle) in a liquid crystal element. Figure 30 shows the light modulated and output by the liquid crystal element 100, and the steering angle θ.

[0127] As shown in the example in Figure 29, a smaller pixel pitch (i.e., the distance between pixels) tends to result in a larger steering angle θ (diffraction angle). Therefore, for example, the pixel pitch may be set to 3 μm or less so that the steering angle θ (diffraction angle in Figure 29) is 10° or more. When the pixel pitch is 3 μm or less, it becomes possible to increase the steering angle and expand the field of view (FOV).

[0128] Figure 31 is a diagram illustrating an example of operation of a liquid crystal element according to Modification 6. Figure 31 shows an example of field sequential driving (i.e., field sequential control) of the liquid crystal element 100. As an example, the cell gap of the liquid crystal element 100 may be set to 1.5 μm or less so that color field sequential driving is possible at a predetermined response speed (for example, 1 / 720 Hz = 1.4 ms).

[0129] In the example shown in Figure 31, when the cell gap is 1.5 μm or less, it is possible to achieve a frame rate of 120 Hz (i.e., frame duration T1 = 3 / 360), a color switching frequency of 360 Hz (i.e., subframe duration T2 = 1 / 360 in each of the effective regions 60r, 60g, and 60b), and a refresh rate of 720 Hz.

[0130] As schematically shown in Figure 31, the spatial light modulation device 1 can drive the effective regions 60r, 60g, and 60b in a time-division manner and perform color field sequential image display. For example, the number of frames per second can be set to a number within the range of 60 to 120, making the motion of moving images smoother. By setting the pixel pitch to 3 μm or less and the cell gap to 1.5 μm or less, it is possible to effectively improve image quality.

[0131] Although the present disclosure has been described above with reference to embodiments and modifications, the present technology is not limited to the above embodiments, and various modifications are possible. For example, although the above-described modifications were described as modifications of the above embodiments, the configurations of each modification can be combined as appropriate.

[0132] A liquid crystal element according to one embodiment of the present disclosure comprises a first substrate having a first electrode provided on each of a plurality of pixels, a second substrate having a second electrode provided opposite to the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate having a first region and a second region. The first region has a first structure having a columnar shape. The optical layer is capable of modulating light in a first wavelength range incident on the first region and is capable of modulating light in a second wavelength range incident on the second region. Therefore, it is possible to realize a liquid crystal element that is advantageous for high image quality.

[0133] A spatial light modulation device according to one embodiment of the present disclosure comprises a liquid crystal element and a control unit capable of controlling the liquid crystal element. The liquid crystal element includes a first substrate having a first electrode provided on each of a plurality of pixels, a second substrate having a second electrode provided opposite to the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate having a first region and a second region. The first region has a first structure having a columnar shape. The optical layer is capable of modulating light in a first wavelength range incident on the first region and is capable of modulating light in a second wavelength range incident on the second region. Therefore, it is possible to realize a spatial light modulation device that is advantageous for high image quality.

[0134] The effects described herein are merely examples and are not limited to those described herein; other effects may also exist. Furthermore, this disclosure may also take the following configurations: (1) A liquid crystal element comprising: a first substrate having a first electrode provided on each of a plurality of pixels; a second substrate having a second electrode provided opposite to the first electrode; a liquid crystal layer provided between the first substrate and the second substrate; and an optical layer provided between the first substrate and the second substrate, having a first region and a second region, wherein the first region has a first structure having a columnar shape, and the optical layer is capable of modulating light in a first wavelength range incident on the first region and is capable of modulating light in a second wavelength range incident on the second region. (2) The liquid crystal element according to (1) above, wherein the optical layer is provided between the first substrate and the liquid crystal layer. (3) The liquid crystal element according to (1) above, wherein the first structure is provided on the first electrode. (4) The liquid crystal element according to (1) above, wherein the optical layer is provided between the second substrate and the liquid crystal layer. (5) The liquid crystal element according to any one of (1) to (4), wherein the optical layer is capable of modulating light in one wavelength range from the red wavelength range, the green wavelength range, and the blue wavelength range as light in the first wavelength range. (6) The liquid crystal element according to any one of (1) to (5), wherein the second region has a second structure having a columnar shape. (7) The liquid crystal element according to (6), wherein the size of the second structure is different from the size of the first structure. (8) The liquid crystal element according to (6) or (7), wherein the optical layer has a first boundary region located between the first region and the second region, and the first boundary region is not provided with the first structure and the second structure. (9) The liquid crystal element according to any one of (6) to (8), wherein the optical layer has a third region provided with a third structure having a columnar shape, and the optical layer is capable of modulating light in a third wavelength range incident on the third region. (10) The liquid crystal element according to (9) above, wherein the first structure, the second structure, and the third structure are of different sizes.(11) The liquid crystal element according to any one of (6) to (10), wherein the optical layer has a first boundary region located between the first region and the second region, and the first boundary region has a fourth structure having a columnar shape. (12) The liquid crystal element according to (11), wherein the first boundary region has a fifth structure having a columnar shape, and the size of the fifth structure is different from the size of the fourth structure. (13) The liquid crystal element according to any one of (6) to (12), wherein the optical layer has a third region provided with a third structure having a columnar shape, and a second boundary region located between the second region and the third region, and the second boundary region is not provided with the second structure and the third structure. (14) The liquid crystal element according to any one of (6) to (13), wherein the first region is located adjacent to the second region, the first structure is provided between the first substrate and the liquid crystal layer, and the second structure is provided between the second substrate and the liquid crystal layer. (15) The liquid crystal element according to any one of (6) to (14), wherein the optical layer has a plurality of first regions and a plurality of second regions, and at least a portion of the plurality of second regions is provided between the plurality of first regions. (16) The liquid crystal element according to any one of (1) to (15), wherein the liquid crystal layer has a first liquid crystal layer provided for the first region and a second liquid crystal layer provided for the second region, and the first liquid crystal layer and the second liquid crystal layer have different liquid crystal materials. (17) The liquid crystal element according to any one of (1) to (16), wherein the liquid crystal layer comprises a first liquid crystal region provided with respect to the first region and containing first liquid crystal molecules, and a second liquid crystal region provided with respect to the second region and containing second liquid crystal molecules, wherein the orientation direction of the second liquid crystal molecules in the second liquid crystal region is different from the orientation direction of the first liquid crystal molecules in the first liquid crystal region. (18) The liquid crystal element according to any one of (1) to (17), wherein the optical layer comprises a member provided around the first structure, and the first structure has a refractive index higher than that of the member.(19) The member comprises an alignment film provided between the first substrate and the second substrate, and the first structure is the liquid crystal element described in (18) provided within the alignment film as the member. (20) A liquid crystal element comprising a liquid crystal element and a control unit capable of controlling the liquid crystal element, wherein the liquid crystal element comprises a first substrate having a first electrode provided on each of a plurality of pixels, a second substrate having a second electrode provided opposite to the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate having a first region and a second region, the first region having a first structure having a columnar shape, and the optical layer being capable of modulating light in a first wavelength range incident on the first region and being capable of modulating light in a second wavelength range incident on the second region.

[0135] This application claims priority based on Japanese Patent Application No. 2024-157912, filed with the Japan Patent Office on 12 September 2024, and all contents of that application are incorporated herein by reference.

[0136] Those skilled in the art will understand that various modifications, combinations, subcombinations, and changes can be conceived depending on design requirements and other factors, and that these fall within the scope of the attached claims and their equivalents.

Claims

1. A liquid crystal element comprising: a first substrate having a first electrode provided on each of a plurality of pixels; a second substrate having a second electrode provided opposite to the first electrode; a liquid crystal layer provided between the first substrate and the second substrate; and an optical layer provided between the first substrate and the second substrate having a first region and a second region, wherein the first region has a first structure having a columnar shape, and the optical layer is capable of modulating light in a first wavelength range incident on the first region and is capable of modulating light in a second wavelength range incident on the second region.

2. The liquid crystal element according to claim 1, wherein the optical layer is provided between the first substrate and the liquid crystal layer.

3. The liquid crystal element according to claim 2, wherein the first structure is provided on the first electrode.

4. The liquid crystal element according to claim 1, wherein the optical layer is provided between the second substrate and the liquid crystal layer.

5. The liquid crystal element according to claim 1, wherein the optical layer is capable of modulating light in one of the wavelength ranges of red, green, and blue as light in the first wavelength range.

6. The liquid crystal element according to claim 1, wherein the second region has a second structure having a columnar shape.

7. The liquid crystal element according to claim 6, wherein the size of the second structure is different from the size of the first structure.

8. The liquid crystal element according to claim 6, wherein the optical layer has a first boundary region located between the first region and the second region, and the first boundary region is not provided with the first structure and the second structure.

9. The liquid crystal element according to claim 6, wherein the optical layer has a third region on which a third structure having a columnar shape is provided, and the optical layer is capable of modulating light in a third wavelength range incident on the third region.

10. The liquid crystal element according to claim 9, wherein the first structure, the second structure, and the third structure are of different sizes.

11. The liquid crystal element according to claim 6, wherein the optical layer has a first boundary region located between the first region and the second region, and the first boundary region has a fourth structure having a columnar shape.

12. The liquid crystal element according to claim 11, wherein the first boundary region has a fifth structure having a columnar shape, and the size of the fifth structure is different from the size of the fourth structure.

13. The liquid crystal element according to claim 6, wherein the optical layer has a third region on which a columnar third structure is provided, and a second boundary region located between the second region and the third region, and the second boundary region is not provided with the second structure or the third structure.

14. The liquid crystal element according to claim 6, wherein the first region is located adjacent to the second region, the first structure is provided between the first substrate and the liquid crystal layer, and the second structure is provided between the second substrate and the liquid crystal layer.

15. The liquid crystal element according to claim 6, wherein the optical layer has a plurality of first regions and a plurality of second regions, and at least a portion of the plurality of second regions is provided between the plurality of first regions.

16. The liquid crystal element according to claim 1, wherein the liquid crystal layer comprises a first liquid crystal layer provided for the first region and a second liquid crystal layer provided for the second region, and the first liquid crystal layer and the second liquid crystal layer are made of different liquid crystal materials.

17. The liquid crystal element according to claim 1, wherein the liquid crystal layer comprises a first liquid crystal region provided with respect to the first region and containing first liquid crystal molecules, and a second liquid crystal region provided with respect to the second region and containing second liquid crystal molecules, wherein the orientation direction of the second liquid crystal molecules in the second liquid crystal region is different from the orientation direction of the first liquid crystal molecules in the first liquid crystal region.

18. The liquid crystal element according to claim 1, wherein the optical layer has a member provided around the first structure, and the first structure has a refractive index higher than that of the member.

19. The liquid crystal element according to claim 18, wherein the member comprises an alignment film provided between the first substrate and the second substrate, and the first structure is provided within the alignment film as the member.

20. A spatial light modulation device comprising a liquid crystal element and a control unit capable of controlling the liquid crystal element, wherein the liquid crystal element comprises a first substrate having a first electrode provided on each of a plurality of pixels, a second substrate having a second electrode provided opposite to the first electrode, a liquid crystal layer provided between the first substrate and the second substrate, and an optical layer provided between the first substrate and the second substrate having a first region and a second region, wherein the first region has a first structure having a columnar shape, and the optical layer is capable of modulating light in a first wavelength range incident on the first region and modulating light in a second wavelength range incident on the second region.

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