Liquid crystal element and phase modulation device

Abstract

A liquid crystal element according to one 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; and a liquid crystal layer provided between the first substrate and the second substrate. The second electrode is provided so as to have a plurality of first portions facing the first electrode for each pixel.

Description

Liquid crystal element and phase modulation device

[0001] The present disclosure relates to a liquid crystal element and a phase modulation device.

[0002] A liquid crystal display panel has been proposed that has a transparent counter common electrode made up of two layers, a thin ITO film and a thick ITO film (Patent Document 1).

[0003] Japanese Unexamined Patent Publication No. 62-240933

[0004] Liquid crystal elements are required to suppress deterioration in quality.

[0005] It is desirable to provide a liquid crystal element that can suppress deterioration in quality.

[0006] A 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, and a liquid crystal layer provided between the first and second substrates. The second electrode is provided for each pixel so as to have a plurality of first portions facing the first electrode. A phase modulation device according to an embodiment of the present disclosure includes a liquid crystal element and a controller 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, and a liquid crystal layer provided between the first and second substrates. The second electrode is provided for each pixel so as to have a plurality of first portions facing the first electrode.

[0007] FIG. 1 is a diagram illustrating an example of a schematic configuration of a phase modulation device according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a pixel unit of a liquid crystal element according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a configuration of a liquid crystal element according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of a configuration of a liquid crystal element according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a configuration of a liquid crystal element according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of a configuration of a liquid crystal element according to a comparative example of the present disclosure. FIG. 7 is a diagram illustrating an example of a configuration of a liquid crystal element according to an embodiment of the present disclosure. FIG. 8A is a diagram illustrating an example of a configuration of a liquid crystal element according to a first modification of the present disclosure. FIG. 8B is a diagram illustrating an example of a configuration of a liquid crystal element according to the first modification of the present disclosure. FIG. 8C is a diagram illustrating an example of a configuration of a liquid crystal element according to the first modification of the present disclosure. FIG. 8D is a diagram illustrating an example of a configuration of a liquid crystal element according to the first modification of the present disclosure. FIG. 8E is a diagram illustrating an example of a configuration of a liquid crystal element according to the first modification of the present disclosure. FIG. 9 is a diagram illustrating an example of a configuration of a liquid crystal element according to a second modification of the present disclosure. FIG. 10 is a diagram showing an example of a pixel portion of a liquid crystal element according to Modification 3 of the present disclosure. FIG. 11A is a diagram showing an example of a cross-sectional configuration of a liquid crystal element according to Modification 3 of the present disclosure. FIG. 11B is a diagram showing an example of a cross-sectional configuration of a liquid crystal element according to Modification 3 of the present disclosure. FIG. 12 is a diagram showing an example of a pixel portion of a liquid crystal element according to Modification 4 of the present disclosure. FIG. 13 is a diagram showing an example of a cross-sectional configuration of a liquid crystal element according to Modification 4 of the present disclosure. FIG. 14 is a diagram for explaining an example of a configuration of a liquid crystal element according to Modification 5 of the present disclosure. FIG. 15A is a diagram for explaining an example of a configuration of a liquid crystal element according to Modification 6 of the present disclosure. FIG. 15B is a diagram for explaining an example of a configuration of a liquid crystal element according to Modification 6 of the present disclosure. FIG. 15C is a diagram for explaining an example of a configuration of a liquid crystal element according to Modification 6 of the present disclosure. FIG. 16 is a diagram for explaining an example of a configuration of a liquid crystal element according to Modification 7 of the present disclosure.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made 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 2-7. Modification 7

[0009] 1 is a diagram illustrating an example of a schematic configuration of a phase modulation device according to an embodiment of the present disclosure. The phase modulation device 1 is a device capable of modulating the phase of light. The phase modulation device 1 controls the phase of light using a liquid crystal element. The phase modulation device 1 is a spatial light modulator (SLM) that can arbitrarily control the phase of light.

[0010] The phase modulation device 1 is configured as, for example, a liquid crystal type spatial light phase modulator. As an example, the phase modulation device 1 can control the wavefront of light and output any pattern light. The phase modulation device 1 is, for example, a spatial light modulator using LCOS (Liquid Crystal on Silicon). The phase modulation device 1 (light modulation device) can be applied to various display devices and optical devices. As an example, the phase modulation device 1 can be applied to a laser processing device.

[0011] The phase modulation device 1 can be applied to, for example, displays (e.g., 3D display devices, devices that modulate backlights), in-vehicle applications (e.g., head-up displays (HUDs), headlights, and light detection and ranging (LiDAR)). Furthermore, for example, the phase modulation device 1 can be used in optical devices (optical elements) such as optical switches and antennas. The phase modulation device 1 can be applied to various devices having an optical modulation function.

[0012] The phase modulation device 1 has, for example, a signal processing unit 10, a driving unit 20, and a liquid crystal element 100. The signal processing unit 10 is a signal processing circuit and is configured to be able to perform signal processing (information processing). The signal processing unit 10 has, for example, a processor and memory (ROM, RAM, etc.) and is configured to perform various types of signal processing. The signal processing unit 10 can read and execute a program embedded therein to perform signal processing (information processing).

[0013] The signal processing unit 10 also functions as a control unit (control circuit) and can be configured to be able to control each unit of the phase modulation device 1. The signal processing unit 10 is configured to control, for example, the drive unit 20. The signal processing unit 10 supplies a signal that controls the drive unit 20 to the drive unit 20, and controls the operation of the drive unit 20. The signal processing unit 10 can control the operation of the liquid crystal element 100 via the drive unit 20. The signal processing unit 10 and the drive unit 20 together can also be referred to as a control unit (or element control unit).

[0014] The signal processing unit 10 is configured to be able to generate data relating to the amount of phase modulation (referred to as phase distribution data). The signal processing unit 10 generates, for example, data relating to the amount of phase modulation for each pixel of the liquid crystal element 100 as phase distribution data (phase distribution information). The phase distribution data is data relating to the distribution of the amount of phase modulation set in the liquid crystal element 100, and can also be said to be data relating to the magnitude of the voltage (potential difference) supplied between the electrodes of each pixel of the liquid crystal element 100. The phase distribution data is also referred to as a phase pattern or a hologram pattern. In particular, a hologram pattern calculated by a computer is also referred to as a CGH (Computer Generated Hologram).

[0015] The signal processing unit 10 generates phase distribution data by, for example, performing light propagation calculations. As an example, the signal processing unit 10 may generate phase distribution data related to the phase modulation amount for each pixel and output the phase distribution data to the driver 20. The signal processing unit 10 can also be considered a data processing unit (processing circuit) configured to be able to execute data processing. Note that the phase distribution data may be generated in the phase modulation device 1, or the signal processing unit 10 may acquire phase distribution data generated in an external device.

[0016] The liquid crystal element 100 is a light modulation element and is configured to be able to modulate the phase of incident light, for example. The liquid crystal element 100 is configured as a phase modulation element and controls the phase of light from the light source 50 by using liquid crystal. The liquid crystal element 100 is, for example, a liquid crystal panel having a pixel section 101 including a plurality of pixels. The liquid crystal element 100 (phase modulation element) may be a reflective liquid crystal element or a transmissive liquid crystal element. The liquid crystal element 100 may be, for example, an LCOS panel.

[0017] The driving unit 20 is configured to be able to drive the liquid crystal element 100. The driving unit 20 is a driving circuit, and is configured to drive each pixel of the pixel unit 101 of the liquid crystal element 100. The driving unit 20 is configured by a plurality of circuits including, for example, a digital-to-analog converter (DAC), an amplifier circuit, etc., and can control the operation of the liquid crystal element 100.

[0018] The driving unit 20 is configured to be able to control, for example, a voltage to each pixel of the pixel unit 101. The driving unit 20 can also be said to be a control unit (control circuit) configured to be able to control the liquid crystal element 100. The driving unit 20 supplies a voltage to the liquid crystal element 100 for driving the pixels, and can control phase modulation by each pixel of the liquid crystal element 100. Note that at least a part of the liquid crystal element 100 and the driving unit 20 may be configured integrally.

[0019] The driver 20 receives, for example, phase distribution data from the signal processor 10. Based on the phase distribution data, the driver 20 sets the magnitude 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. The driver 20 can control the voltage to be supplied to each pixel of the liquid crystal element 100, and adjust the amount of phase modulation at each pixel, so as to obtain a distribution of the amount of phase modulation indicated by the phase distribution data, for example.

[0020] The light source 50 is configured to be able to irradiate light onto the liquid crystal element 100. The light source 50 is configured using, for example, a single or multiple light-emitting elements such as an LD (Laser Diode) or an LED (Light Emitting Diode), and can output light (ultraviolet light, visible light, near-infrared light, etc.) to the outside. As an example, the light source 50 can generate laser light and emit the laser light to the outside.

[0021] The phase modulation device 1 can perform wavefront control of light by, for example, diffracting light from a light source 50 using a liquid crystal element 100. The phase modulation device 1 may be configured to include a light source 50. The light source 50 may be configured using a semiconductor laser element, for example, a vertical cavity surface emitting laser (VCSEL).

[0022] The driving unit 20 can control the rotation angle of the liquid crystal molecules, for example, by controlling the voltage applied to each pixel of the liquid crystal element 100. In the liquid crystal element 100, the rotation angle of the liquid crystal molecules in each pixel changes according to the input voltage at predetermined time intervals (e.g., every frame), modulating the phase of incident light. The phase modulation device 1 dynamically and efficiently controls the phase of light, and can reproduce (display) output light having an arbitrary two-dimensional intensity distribution on an arbitrary focal plane.

[0023] In the liquid crystal element 100, the voltage at each pixel is adjusted so as to impart a desired phase distribution (e.g., a lens-like phase distribution, a blazed diffraction grating-like phase distribution, etc.) to incident light. The liquid crystal element 100 can, for example, focus light based on set phase distribution data. Furthermore, for example, the liquid crystal element 100 can deflect light in any direction.

[0024] Fig. 2 is a diagram showing an example of a pixel section of a liquid crystal element according to an embodiment. As an example, the liquid crystal element 100 has a region (pixel section 101) in which a plurality of pixels P are arranged, as shown in Fig. 2. In the example shown in Fig. 2, the incident direction of light from the light source 50 is the Z-axis direction, the direction perpendicular to the Z-axis direction is the X-axis direction, and the direction perpendicular to the Z-axis and X-axis directions is the Y-axis direction. In the following figures, directions may be indicated based on the direction of the arrow in Fig. 2.

[0025] 2, the plurality of pixels P of the liquid crystal element 100 are arranged two-dimensionally in the X-axis direction and the Y-axis direction. The liquid crystal element 100 has a plurality of pixels P and is configured to be able to control the phase of light for each pixel P. Note that the number and arrangement of the pixels P provided in the pixel section 101 are not limited to the example shown in the figure and can be changed as appropriate.

[0026] 3 and 4 are diagrams for explaining an example of the configuration of a liquid crystal element according to an embodiment. Fig. 3 shows an example of the cross-sectional configuration of a liquid crystal element 100. The liquid crystal element 100 has a substrate 105, a liquid crystal layer 110, and a substrate 106. Note that the outline arrows in Fig. 3 schematically indicate incident light from a light source 50. Fig. 4 shows an example of the planar configuration of the substrate 105 of the liquid crystal element 100.

[0027] The substrates 105 and 106 are spaced apart from each other in the stacking direction (the Z-axis direction in FIG. 3 ). The liquid crystal element 100 has a configuration in which the substrate 105, the liquid crystal layer 110, and the substrate 106 are stacked in the Z-axis direction. The substrates 105 and 106 are arranged to face each other. The substrates 105 and 106 are fixed together with the liquid crystal layer 110 sandwiched therebetween by a sealant (not shown).

[0028] The substrate 105 is a substrate that transmits light (transparent substrate) and is made of, for example, a glass substrate. The substrate 105 may be made of quartz glass, borosilicate glass, or other material (base material) that transmits incident light. The substrate 105 is provided with an electrode 120 and an insulating member 140.

[0029] The substrate 106 is a support substrate and is made of a semiconductor substrate (e.g., a silicon substrate), a glass substrate, or the like. An electrode 130 is provided on the substrate 106. The electrode 120 and the electrode 130 are disposed with the liquid crystal layer 110 sandwiched between them. The electrode 120 is an opposing electrode and is disposed so as to face the electrode 130 with part of the liquid crystal layer 110 sandwiched between them.

[0030] The electrode 120 is, for example, an electrode common to a plurality of pixels P, and is provided on one surface of the substrate 105. The electrode 120 can also be called a common electrode. The electrode 120 is, for example, provided on the substrate 105, between the substrate 105 and the liquid crystal layer 110. The electrode 120 has a lattice shape in a plan view, for example, as shown in the example of FIG.

[0031] 3 and 4, the electrode 120 is formed by patterning at a period shorter than the period of the pixels P (i.e., the width of the pixels). The electrode 120 is provided so as to have a plurality of portions 121 facing the electrode 130 for each pixel P. The electrode 120 can also be said to be a structure in which the plurality of portions 121 as a plurality of structural parts are integrated.

[0032] The electrode 130 is an electrode provided for each pixel P, and is provided on one surface of the substrate 106. The electrode 130 can be considered a pixel electrode. In the example shown in FIG. 3 , three portions 121 of the electrode 120 are arranged for one pixel P (or one electrode 130).

[0033] 3, the insulating member 140 is provided around the electrode 120. The electrode 120 is provided so that the surface (end face) of the electrode 120 is exposed from the insulating member 140. The insulating member 140 (insulating film) is formed using an insulating material such as silicon oxide (SiO) or silicon nitride (SiN). The insulating member 140 can also be called a protective member (protective layer).

[0034] The electrodes 120 and 130 are electrically connected to circuits, terminals, etc. provided on the substrate 106 via, for example, different wirings, pads, etc. Elements such as transistors and wirings for driving each pixel P may be formed on the substrate 106.

[0035] The electrode 120 (counter electrode) is a transparent electrode and is made of, for example, ITO (indium tin oxide). The electrode 120 may be made of IZO (indium zinc oxide). The electrode 120 may also be made of other tin oxide-based materials, zinc oxide-based materials, or other transparent conductive materials.

[0036] The electrode 130 (pixel electrode) is made of a metal material such as aluminum (Al) or copper (Cu). The electrode 130 may be configured as a transparent electrode. The electrode 130 may be formed using a light-reflecting material or a transparent material such as ITO or IZO.

[0037] The liquid crystal layer 110 is a layer containing a plurality of liquid crystal molecules, and is provided between the substrate 105 and the substrate 106. The liquid crystal layer 110 is sealed between the substrate 105 and the substrate 106 by a sealing material. When a voltage is applied between the electrode 120 and the electrode 130, the liquid crystal molecules in the liquid crystal layer 110 respond, and the orientation of the liquid crystal molecules can be controlled.

[0038] The liquid crystal element 100 may have an alignment film provided on the liquid crystal layer 110. For example, an alignment film may be provided between the liquid crystal layer 110 and the electrode 120 and between the liquid crystal layer 110 and the electrode 130. The alignment film may be formed, for example, from a film formed by obliquely evaporating silicon oxide (obliquely evaporated film), a polyimide film that has been subjected to an alignment treatment such as rubbing, or the like.

[0039] The alignment film can align the liquid crystal molecules of the liquid crystal layer 110 in a specific direction. The liquid crystal molecules of the liquid crystal layer 110 are held in a tilted state by the alignment film. That is, a predetermined pretilt angle (tilt angle) is imparted to the liquid crystal molecules of the liquid crystal layer 110. The alignment film can be said to be a film (layer) that can control the alignment of the liquid crystal molecules.

[0040] In the liquid crystal element 100, the electric field in the liquid crystal layer 110 changes and the orientation of the liquid crystal molecules changes depending on the voltage supplied between the electrode 120 and the electrode 130. By controlling the voltage supplied to the electrode 130 of each pixel P, the orientation of the liquid crystal molecules can be adjusted for each pixel P, changing the refractive index and changing the optical path length.

[0041] In the phase modulation device 1, light incident on each pixel P of the liquid crystal element 100 is emitted after being phase-modulated, for example, according to the tilt amount of the liquid crystal molecules of each pixel P. The liquid crystal element 100 generates a phase delay that differs for each pixel P in the incident light, making it possible to propagate light with a desired wavefront.

[0042] In the liquid crystal element 100, the electrode 120 is patterned at a period shorter (finer) than the period at which the pixels P are arranged. The electrode 120 has a periodicity greater than one, for example, three times, that of one pixel P (or one electrode 130). The electrode 120 has a plurality of finely patterned portions 121, and can have a periodic structure shorter than the period (arrangement interval) of the pixels P.

[0043] The multiple portions 121 of the electrode 120 are arranged side by side in the X-axis direction (or Y-axis direction), for example, with part of the insulating member 140 sandwiched between them. In the example shown in Fig. 3, three portions 121 are provided so as to correspond to one electrode 130. The electrode 120 is also provided so that the distance between adjacent portions 121 is smaller than the width of the pixel P. In the example shown in Fig. 3, the distance D between adjacent portions 121 is smaller than the width W1 of the pixel P.

[0044] 5, the electrode 120 is provided so as to have a plurality of openings 125 for one pixel P (or one electrode 130). The insulating member 140 of the liquid crystal element 100 is formed so as to cover the plurality of portions 121 and fill the openings 125 (holes), for example.

[0045] As an example, the opening 125 of the electrode 120 has a rectangular shape in a plan view. The electrode 120 is provided so that the width of the opening 125 is smaller than the width of the pixel P. In the example shown in Fig. 5, the width W2 of the opening 125 is smaller than the width W1 of the pixel P. Note that the shape of the opening 125 in each pixel P can be changed as appropriate, and may be a circle, an ellipse, a polygon, or another shape.

[0046] As described above, the liquid crystal element 100 has a finely patterned electrode 120 (counter electrode). This makes it possible to suppress deterioration of the characteristics of the liquid crystal element 100 due to light absorption in the electrode 120. For example, it is possible to suppress absorption of incident light (e.g., UV light) and heat generation in the electrode 120, thereby suppressing damage to the liquid crystal element 100.

[0047] If the counter electrode is not patterned or is patterned with a period equal to the period of the pixels, the absorption of UV light by the counter electrode increases, which may cause damage to the liquid crystal element (e.g., alignment abnormality). This may accelerate the deterioration of the liquid crystal element 100, causing damage to the liquid crystal element in a short period of time.

[0048] In the comparative example shown in Fig. 6, that is, when the electrodes 120 are patterned at a period equal to the period of the pixels P, there is a risk of distortion of the electric field distribution in the liquid crystal layer 110, as schematically shown by the dashed arrows in Fig. 6. In this case, the phase distribution deviates from the ideal distribution, which causes a disturbance in the intensity distribution of the reproduced image and a decrease in the light utilization efficiency.

[0049] In the phase modulation device 1 according to this embodiment, the electrode 120 of the liquid crystal element 100 is patterned at a period shorter (finer) than the period of the pixels P. The electrode 120 is provided, for example, for each pixel P so as to have a plurality of portions 121 facing the electrode 130. This makes it possible to suppress light absorption and heat generation in the electrode 120 and to suppress deterioration of the characteristics of the liquid crystal element 100. This makes it possible to improve the reliability of the liquid crystal element 100 (and the phase modulation device 1).

[0050] In the liquid crystal element 100, the overall area of ​​the electrode 120 can be reduced while maintaining the thickness of the electrode 120, and the volume of the electrode 120 through which incident light passes can be reduced. This makes it possible to prevent an increase in the sheet resistance of the electrode 120 and a decrease in the response speed of the liquid crystal element 100.

[0051] Furthermore, by providing the finely patterned electrodes 120, it is possible to flatten the electric field distribution in the liquid crystal layer 110, as shown schematically by the dashed arrows in Fig. 7. This makes it possible to suppress the occurrence of disturbances in the electric field distribution in the liquid crystal layer 110. This makes it possible to prevent adverse effects on the phase distribution, and improve the light utilization efficiency and the quality of the reproduced image.

[0052] As described above, in this embodiment, it is possible to improve the characteristics against incident light, particularly resistance to UV light (ultraviolet light resistance). This makes it possible to prevent damage to the liquid crystal element 100 and shortened lifespan. It is also possible to improve UV transparency. This makes it possible to improve applicability to applications such as laser marking and laser processing, for example. Furthermore, it is possible to improve UV resistance without developing new materials for the electrodes, thereby preventing increases in costs.

[0053] [Functions and Effects] The liquid crystal element (liquid crystal element 100) according to this embodiment includes a first substrate (substrate 106) having a first electrode (electrode 130) provided for each of a plurality of pixels, a second substrate (substrate 105) having a second electrode (electrode 120) provided so as to face the first electrode, and a liquid crystal layer (liquid crystal layer 110) provided between the first and second substrates. The second electrode is provided for each pixel so as to have a plurality of first portions (portions 121) facing the first electrode.

[0054] In the liquid crystal element 100 according to the present embodiment, the electrode 120 is provided so as to have a plurality of portions 121 facing the electrode 130 for each pixel P. This makes it possible to suppress deterioration in the characteristics of the liquid crystal element 100. It is possible to realize a liquid crystal element that can suppress deterioration in quality.

[0055] Next, a modified example of the present disclosure will be described. In the following, the same components as those in the above-described embodiment will be denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

[0056] 2. Modifications (2-1. Modification 1) In the above-described embodiment, exemplary configurations of liquid crystal elements have been described, but the configuration of the liquid crystal element is not limited to the above-described examples. Figures 8A to 8E are diagrams for explaining exemplary configurations of a liquid crystal element according to Modification 1 of the present disclosure. Electrode 120 of liquid crystal element 100 may be configured to have a circular opening 125, as in the example shown in Figure 8A, for example.

[0057] The opening 125 of the electrode 120 may have a rounded shape, as in the example shown in Figure 8B. The electrode 120 may have a structure shown in Figures 8C to 8E. As in the examples shown in Figures 8C to 8E, the opening 125 of the electrode 120 may have a rectangular or polygonal shape in plan view. The portion 121 of the electrode 120 may have a rounded shape.

[0058] (2-2. Modification 2) Fig. 9 is a diagram for explaining a configuration example of a liquid crystal element according to Modification 2. As shown in Fig. 9, the electrode 120 of the liquid crystal element 100 may have a plurality of portions 121 and portions 122. For example, as in the example shown in Fig. 9, the portion 122 of the electrode 120 is provided so as to cover the plurality of portions 121 and connect the plurality of portions 121.

[0059] The electrode 120 has a structure in which, for example, a plurality of portions 121 and a portion 122 are integrated. The plurality of portions 121 are electrically connected via the portions 122. The portions 122 of the electrode 120 can also be referred to as a conductive layer (or a conductive member). The portions 122 of the electrode 120 can be made of a transparent conductive material such as ITO or IZO.

[0060] In the liquid crystal element 100 according to this modification, the provision of the portion 122 (conductive layer) of the electrode 120 reduces the overall resistance of the electrode 120. This improves the response performance of the liquid crystal element 100. It becomes possible to drive each pixel P at a higher frequency.

[0061] If the thickness (film thickness) of the portion 122 in the Z-axis direction is too thick, there is a risk that the absorption of incident light (e.g., UV light) and heat generation in the portion 122 will increase. Therefore, the thickness d (film thickness) of the portion 122 of the electrode 120 is made thin as shown in the example schematically in Fig. 9. The thickness d of the portion 122 is designed to be sufficiently thin so as to reduce the absorption of UV light, for example.

[0062] (2-3. Modification 3) Fig. 10 is a diagram showing an example of a pixel portion of a liquid crystal element according to Modification 3. Figs. 11A and 11B are diagrams showing an example of a cross-sectional configuration of a liquid crystal element according to Modification 3. Fig. 11A shows an example of the configuration of a pixel in region R11 shown in Fig. 10. Fig. 11B shows an example of the configuration of a pixel in region R12 shown in Fig. 10.

[0063] The pixel section 101 of the liquid crystal element 100 has, for example, a plurality of blocks B (a total of 12 blocks, blocks B11 to B34, in FIG. 10 ). Each of these blocks is one region when the region in which pixels P are arranged in the pixel section 101 is divided into regions including a predetermined number of pixels P.

[0064] In each block B, for example, a plurality of pixels P may be arranged two-dimensionally in the X-axis direction and the Y-axis direction. The blocks B may also be called pixel blocks. Note that the number and shape of the blocks B in the pixel unit 101 are not limited to the example shown in the figure and may be changed as appropriate.

[0065] The liquid crystal element 100 may have wiring 150 that electrically connects portions 121 of the electrodes 120 in each of the plurality of pixels P. The wiring 150 is a bus line, and is provided, for example, for each block B or for each of a plurality of blocks B. As an example, the wiring 150 is provided for the plurality of blocks B, and electrically connects portions 121 of the electrodes 120 in each of the plurality of blocks B.

[0066] 10, the wiring 150 electrically connects the multiple portions 121 arranged in each of the blocks B11 to B34. The wiring 150 is made of a transparent conductive material such as ITO or IZO. The wiring 150 may be made of a conductive material such as gold (Au) or copper (Cu), or may be made of another metal material.

[0067] The wiring 150 may be provided to connect the portions 121 of each pixel P aligned in the X-axis direction to the portions 121 of each pixel P aligned in the Y-axis direction. In the example shown in FIG. 11B , the portions 121 provided for the left pixel P (pixel P2a), the central pixel P (pixel P2b), and the right pixel P (pixel P2c) are electrically connected to each other via the wiring 150.

[0068] The liquid crystal element (liquid crystal element 100) of this modified example includes wiring (wiring 150) that electrically connects a plurality of first portions (portions 121) arranged in a first direction (e.g., the X-axis direction) in a first pixel (e.g., pixel P2a) and a plurality of first portions (portions 121) arranged in a first direction (e.g., the X-axis direction) in a second pixel (e.g., pixel P2b).

[0069] In the liquid crystal element 100 according to this modification, the provision of the wiring 150 reduces the resistance of the entire electrodes of the liquid crystal element 100. This makes it possible to improve the response performance of the liquid crystal element 100. It becomes possible to drive each pixel P at a higher frequency.

[0070] (2-4. Modification 4) FIG. 12 is a diagram showing an example of a pixel portion of a liquid crystal element according to Modification 4. FIG. 13 is a diagram showing an example of a cross-sectional configuration of a liquid crystal element according to Modification 4. The liquid crystal element 100 may have a conductive member 160 and a pad 165. As in the example schematically shown in FIG. 13, the conductive member 160 is provided between the substrate 105 and the substrate 106. The pad 165 is provided on the substrate 106.

[0071] The conductive members 160 and pads 165 are provided, for example, for each block B or for each set of multiple blocks B. In the example shown in Fig. 12, the conductive members 160 and pads 165 are arranged in each of the blocks B11 to B34. Note that multiple conductive members 160 and multiple pads 165 may be arranged for each block B.

[0072] The conductive member 160 may be made of a metal material such as gold (Au), copper (Cu), or other conductive material. The pad 165 is an electrode made of a conductive material such as aluminum (AL), gold (Au), copper (Cu), or other conductive material. The pad 165 is a pad electrode, and is electrically connected to the circuit elements, wiring, etc. of the liquid crystal element 100.

[0073] The liquid crystal element (liquid crystal element 100) according to this modification includes a first conductive member (conductive member 160) provided between a first substrate (substrate 106) and a second substrate (substrate 105). The first substrate has a first pad (pad 165) electrically connected to a second electrode (electrode 120) via the first conductive member.

[0074] In the liquid crystal element 100 according to this modification, the electrode 120 of the liquid crystal element 100 is electrically connected to the pad 165 via the conductive member 160. This makes it possible to supply a potential (voltage) to the electrode 120 via the pad 165 and the conductive member 160. This reduces the resistance of the entire electrode. This makes it possible to drive each pixel P at a higher frequency.

[0075] In the liquid crystal element 100, the electrodes 120 in each block B may be electrically isolated from one another. In this case, potentials can be supplied to the pixels P in the blocks B11 to B34 via separate electrodes 120 and pads 165, etc. The separate electrodes 120 make it possible to supply different potentials (voltages) to the pixels P in the blocks B11 to B34.

[0076] In the liquid crystal element according to this modification, a first block (e.g., block B11) has a first pad (pad 165) provided on the first substrate side and a first conductive member (conductive member 160) that electrically connects the first pad and the second electrode. A second block (e.g., block B12) has a second pad (pad 165) provided on the first substrate side and a second conductive member (conductive member 160) that electrically connects the second pad and the third electrode.

[0077] In the liquid crystal element 100 according to this modification, separate electrodes 120, conductive members 160, and pads 165 may be provided for the multiple blocks B. In this case, the resistance of the entire electrode can be reduced, and each pixel P can be driven at a higher frequency. Also, it becomes possible to individually (independently) control the potentials supplied to the multiple blocks B.

[0078] (2-5. Modification 5) Fig. 14 is a diagram for explaining a configuration example of a liquid crystal element according to Modification 5. As shown in Fig. 14, the liquid crystal element 100 may have a light-shielding member 170. The light-shielding member 170 is provided, for example, on the light-incident side of the substrate 105. At least a part of the light-shielding member 170 is provided at the boundary between adjacent pixels P, as in the example shown in Fig. 14.

[0079] The light-shielding member 170 is configured by, for example, a single layer film or a laminated film made of silver (Ag), aluminum (AL), etc. Note that the light-shielding member 170 (light-shielding film) may be configured by laminating multiple films having different refractive indices.

[0080] In the liquid crystal element 100 according to this modification, the provision of the light-shielding member 170 makes it possible to reflect unnecessary light, for example, UV light incident on the non-display area, thereby suppressing light absorption and heat generation in the liquid crystal element 100 and making it possible to suppress deterioration of the characteristics of the liquid crystal element 100.

[0081] 15A to 15C are diagrams illustrating an example of the configuration of a liquid crystal element according to Modification 6. As schematically illustrated in FIG. 15A , the electrode 120 of the liquid crystal element 100 may have portions 121 that have different shapes or are arranged at different densities depending on the distance from the center of the liquid crystal element 100 (or the pixel section 101). For example, the shape (or density) of the portions 121 in the peripheral portion of the electrode 120 may be different from the shape (or density) of the portions 121 in the central portion of the electrode 120.

[0082] 15B or 15C , an electrode 120 having portions 121 with different shapes may be provided in a plurality of regions (e.g., regions R1, R2, and R3) of the pixel unit 101. Furthermore, for example, the liquid crystal element 100 may be configured such that the density of the portions 121 of the electrode 120 differs in each of the regions R1 to R3 depending on the distance from the center of the liquid crystal element 100 (or the pixel unit 101).

[0083] In the liquid crystal element 100 according to this modification, the area density can be changed for each region by changing the pattern shape of the electrode 120. For example, the pattern shape of the electrode 120 can be adjusted in accordance with the intensity distribution of incident light, thereby enabling the life of the liquid crystal element 100 to be extended.

[0084] (2-7. Modification 7) FIG. 16 is a diagram illustrating a configuration example of a liquid crystal element according to Modification 7. As shown in FIG. 16, the liquid crystal element 100 may have a filling member 180. For example, as in the example shown in FIG. 16, the filling member 180 is provided so as to fill the spaces between a plurality of adjacent portions 121. The portions 121 of the electrode 120 are arranged so as to be embedded in the filling member 180.

[0085] The filling member 180 is made of, for example, a material having a refractive index lower than that of the electrode 120. The filling member 180 may have a refractive index higher than that of the substrate 105. The filling member 180 is made of, for example, silicon dioxide (SiO ２ ) The filler member 180 is formed using, for example, hafnium oxide (HfO), aluminum oxide (AlO), or the like. Note that the filler member 180 may be formed using other metal compounds (metal oxides, metal nitrides, etc.) or other materials.

[0086] In the liquid crystal element 100 according to this modification, the provision of the filler member 180 can suppress the generation of unnecessary diffracted light and reflected light as shown by the dashed lines in Fig. 16. This can improve the light utilization efficiency, and can improve the image quality of the reproduced image, for example.

[0087] Although the present disclosure has been described above by way of embodiments and modifications, the present technology is not limited to the above embodiments, etc., and various modifications are possible. For example, although the modifications described above have been described as modifications of the above embodiments, the configurations of the modifications can be combined as appropriate.

[0088] The liquid crystal element according to the present disclosure can be configured as a liquid crystal element that modulates the phase of light, a liquid crystal element that modulates the brightness of light, etc. The liquid crystal element according to the present disclosure can be applied to various light modulation elements. The liquid crystal element and phase modulation device according to the present disclosure can be applied to various devices.

[0089] A 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 to face the first electrode, and a liquid crystal layer provided between the first substrate and the second substrate. The second electrode is provided for each pixel so as to have a plurality of first portions facing the first electrode. This makes it possible to suppress deterioration of the characteristics of the liquid crystal element. This makes it possible to realize a liquid crystal element capable of suppressing deterioration in quality.

[0090] A phase modulation device 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 opposite the first electrode, and a liquid crystal layer provided between the first substrate and the second substrate. The second electrode is provided for each pixel so as to have a plurality of first portions that face the first electrode. This makes it possible to realize a phase modulation device that can suppress degradation in quality.

[0091] Note that the effects described in this specification are merely examples and are not limited to those described above, and other effects may be present. The present disclosure may also have the following configurations. (1) A liquid crystal element comprising: a first substrate having a first electrode provided in each of a plurality of pixels; a second substrate having a second electrode provided so as to face the first electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein the second electrode is provided so as to have a plurality of first portions facing the first electrode for each of the pixels. (2) The liquid crystal element according to (1), wherein the second electrode is patterned at a period shorter than the period of the pixels. (3) The liquid crystal element according to (1) or (2), wherein the plurality of first portions are arranged in a first direction, and the distance between adjacent first portions is smaller than the width of the pixel. (4) The liquid crystal element according to any one of (1) to (3), wherein the second electrode is provided so as to have a plurality of openings for each of the pixels. (5) The liquid crystal element according to (4), wherein the width of the opening is smaller than the width of the pixel. (6) The liquid crystal element according to any one of (1) to (5), wherein the second electrode has a lattice shape in a planar view. (7) The liquid crystal element according to any one of (1) to (6), wherein the second electrode is provided so as to cover the plurality of first portions and further has a second portion connecting the plurality of first portions. (8) The liquid crystal element according to any one of (1) to (7), wherein the plurality of pixels include a first pixel and a second pixel, and the first pixel and the second pixel each include the first electrode and the plurality of first portions. (9) The liquid crystal element according to (8), further including wiring that electrically connects the plurality of first portions provided to be aligned in a first direction in the first pixel and the plurality of first portions provided to be aligned in the first direction in the second pixel. (10) The liquid crystal element according to (9), further comprising a plurality of blocks each including a plurality of the pixels, wherein the wiring is provided for each of the blocks or for each of a plurality of the blocks.(11) The liquid crystal element according to any one of (1) to (10), further comprising a first conductive member provided between the first substrate and the second substrate, wherein the first substrate further comprises a first pad electrically connected to the second electrode via the first conductive member. (12) The liquid crystal element according to (11), further comprising a plurality of blocks each including a plurality of the pixels, wherein the first conductive member and the first pad are provided for each of the blocks or for each of a plurality of the blocks. (13) The liquid crystal element according to any one of (1) to (12), further comprising a light-shielding member provided on the light-incident side of the second substrate, wherein at least a portion of the light-shielding member is provided at the boundary between adjacent pixels. (14) The liquid crystal element according to any one of (1) to (13), further comprising a first region and a second region each including a plurality of the pixels, wherein a shape of the second electrode in the first region is different from a shape of the second electrode in the second region. (15) The liquid crystal element according to any one of (1) to (14), further comprising a first region and a second region each having a plurality of the pixels, wherein the density of the second electrode in the first region is different from the density of the second electrode in the second region. (16) The liquid crystal element according to any one of (1) to (15), further comprising a filling member provided around the second electrode and having a refractive index lower than the refractive index of the second electrode, wherein the filling member is provided so as to fill spaces between adjacent first portions. (17) The filling member is made of silicon dioxide (SiO. ２(18) The liquid crystal element according to any one of (1) to (17), further comprising a first block and a second block each including a plurality of the pixels, wherein the first block has: a plurality of first electrodes provided on the first substrate side, the second electrodes provided on the second substrate side to face the first electrodes, a first pad provided on the first substrate side, and a first conductive member provided between the first substrate and the second substrate and electrically connecting the first pad and the second electrode, and the second block has: a plurality of first electrodes provided on the first substrate side, a third electrode provided on the second substrate side to face the first electrode, a second pad provided on the first substrate side, and a second conductive member provided between the first substrate and the second substrate and electrically connecting the second pad and the third electrode. (19) A phase 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 in each of a plurality of pixels; a second substrate having a second electrode provided so as to face the first electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein the second electrode is provided so as to have a plurality of first portions facing the first electrode for each of the pixels.

[0092] This application claims priority based on Japanese Patent Application No. 2023-183687, filed on October 26, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0093] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur depending on design requirements and other factors, and are intended to be within the scope of the appended claims and their equivalents.

Claims

1. A liquid crystal element comprising: a first substrate having a first electrode provided in each of a plurality of pixels; a second substrate having a second electrode provided so as to face the first electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein the second electrode is provided so as to have a plurality of first portions facing the first electrode for each of the pixels.

2. The liquid crystal element according to claim 1, wherein the second electrode is patterned at a period shorter than the period of the pixels.

3. A liquid crystal element according to claim 1, wherein the first portions are arranged in a first direction, and the distance between adjacent first portions is smaller than the width of the pixel.

4. The liquid crystal element according to claim 1, wherein the second electrode is provided so as to have a plurality of openings for one pixel.

5. The liquid crystal element according to claim 4, wherein the width of the opening is smaller than the width of the pixel.

6. The liquid crystal element according to claim 1, wherein the second electrode has a lattice shape in a plan view.

7. A liquid crystal element according to claim 1, wherein the second electrode is provided so as to cover the plurality of first portions and further has a second portion connecting the plurality of first portions.

8. The liquid crystal element according to claim 1, wherein the plurality of pixels include a first pixel and a second pixel, and each of the first pixel and the second pixel includes the first electrode and the plurality of first portions.

9. A liquid crystal element as described in claim 8, further comprising wiring electrically connecting a plurality of the first portions arranged in the first pixel so as to be aligned in the first direction and a plurality of the first portions arranged in the second pixel so as to be aligned in the first direction.

10. The liquid crystal element according to claim 9, further comprising a plurality of blocks each including a plurality of the pixels, and the wiring is provided for each of the blocks or for each of a plurality of the blocks.

11. A liquid crystal element as described in claim 1, further comprising a first conductive member provided between the first substrate and the second substrate, the first substrate further having a first pad electrically connected to the second electrode via the first conductive member.

12. A liquid crystal element according to claim 11, further comprising a plurality of blocks each including a plurality of the pixels, and the first conductive member and the first pad are provided for each of the blocks or for each of a plurality of the blocks.

13. A liquid crystal element according to claim 1, further comprising a light-shielding member provided on the light-incident side of the second substrate, at least a portion of the light-shielding member being provided on the boundary between adjacent pixels.

14. A liquid crystal element as described in claim 1, further comprising a first region and a second region each having a plurality of the pixels, wherein the shape of the second electrode in the first region is different from the shape of the second electrode in the second region.

15. A liquid crystal element as described in claim 1, further comprising a first region and a second region each having a plurality of the pixels, wherein the density of the second electrodes in the first region is different from the density of the second electrodes in the second region.

16. A liquid crystal element as described in claim 1, further comprising a filling member provided around the second electrode and having a refractive index lower than that of the second electrode, the filling member being provided so as to fill spaces between adjacent first portions.

17. The filling member is made of silicon dioxide (SiO ２ The liquid crystal device according to claim 16, wherein the refractive index is higher than the refractive index of the liquid crystal layer.

18. A liquid crystal element as described in claim 1, further comprising a first block and a second block each including a plurality of the pixels, wherein the first block has: a plurality of the first electrodes provided on the first substrate side; a second electrode provided on the second substrate side so as to face the first electrodes; a first pad provided on the first substrate side; and a first conductive member provided between the first substrate and the second substrate and electrically connecting the first pad and the second electrode; and the second block has: a plurality of the first electrodes provided on the first substrate side; a third electrode provided on the second substrate side so as to face the first electrodes; a second pad provided on the first substrate side; and a second conductive member provided between the first substrate and the second substrate and electrically connecting the second pad and the third electrode.

19. A phase modulation device comprising: a liquid crystal element; and a control unit capable of controlling the liquid crystal element, wherein the liquid crystal element has: a first substrate having a first electrode provided in each of a plurality of pixels; a second substrate having a second electrode provided so as to face the first electrode; and a liquid crystal layer provided between the first substrate and the second substrate, wherein the second electrode is provided so as to have a plurality of first portions facing the first electrode for each of the pixels.

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