Spatial light modulator and display device

Abstract

A spatial light modulator according to one embodiment of the present disclosure comprises: a first substrate that has a plurality of first electrodes disposed in a first direction and a second direction that intersect each other; a second substrate that is disposed facing the first substrate and has a second electrode divided into a plurality of segments that are larger than the plurality of first electrodes; a liquid crystal layer that is provided between the first substrate and the second substrate; a first control circuit that individually controls voltages applied to the plurality of first electrodes; a second control circuit that individually controls voltages applied segment by segment to the second electrode; and a partition wall that is provided between the first substrate and the second substrate, and, at least partially between the plurality of adjacent segments in a plan view.

Description

Spatial light modulator and display device

[0001] The present disclosure relates to spatial light modulators and display devices.

[0002] For example, Patent Document 1 discloses a liquid crystal display device in which a liquid crystal cell is provided at each intersection of a plurality of first signal lines arranged parallel to the vertical direction and a plurality of second signal lines arranged parallel to the horizontal direction, via a selection element. In this liquid crystal display device, the opposing electrode of the liquid crystal cell is divided, and the potential of the electrode is inverted for each division when a video signal is supplied to the liquid crystal cell, thereby eliminating shading and achieving a good display.

[0003] Japanese Patent Application Publication No. 2-312466

[0004] Meanwhile, there is a demand for a spatial light modulator that has high definition and excellent light modulation characteristics.

[0005] It is desirable to provide a spatial light modulator and display device that has high definition and excellent light modulation characteristics.

[0006] A spatial light modulator according to one embodiment of the present disclosure comprises a first substrate having a plurality of first electrodes arranged in a first direction and a second direction that intersect with each other; a second substrate arranged opposite the first substrate and having second electrodes divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls the voltage applied to the plurality of first electrodes; a second control circuit that individually controls the voltage applied to the second electrodes for each division unit; and partition walls provided between the first substrate and the second substrate and at least partially between the plurality of adjacent segments in a planar view.

[0007] A display device according to an embodiment of the present disclosure includes the spatial light modulator according to the embodiment of the present disclosure.

[0008] In a spatial light modulator and a display device according to an embodiment of the present disclosure, a partition wall is provided between a first substrate and a second substrate disposed opposite each other with a liquid crystal layer interposed therebetween. The first substrate has a plurality of first electrodes arranged in a first direction and a second direction that intersect with each other. The second substrate has a second electrode divided into a plurality of segments that are larger than the plurality of first electrodes. Control circuits (first control circuit and second control circuit) that individually control applied voltages are connected to the plurality of first electrodes and the divided second electrodes. The partition wall is provided at least partially between adjacent segments in a plan view. This suppresses fringe electric fields occurring between the segments.

[0009] FIG. 1 is a cross-sectional view schematically illustrating a configuration of a spatial light modulator according to a first embodiment of the present disclosure. FIG. 2 is a view illustrating an overview of the spatial light modulator shown in FIG. 1. FIG. 3A is a view illustrating dielectric characteristics of a liquid crystal element. FIG. 3B is a view illustrating optical characteristics. FIG. 4 is a plan view schematically illustrating an example configuration of a plurality of pixel electrodes and a counter electrode of the spatial light modulator shown in FIG. 1. FIG. 5 is a view illustrating crosstalk due to a fringe electric field. FIG. 6 is a plan view schematically illustrating an example layout of partition walls. FIG. 7A is a cross-sectional view schematically illustrating an example shape of a partition wall. FIG. 7B is a cross-sectional view schematically illustrating an example shape of a partition wall. FIG. 7C is a cross-sectional view schematically illustrating an example shape of a periphery of a partition wall. FIG. 7D is a cross-sectional view schematically illustrating an example shape of a periphery of a partition wall. FIG. 8 is a block diagram illustrating the overall configuration of a spatial light modulator. FIG. 9 is a view illustrating an example configuration of a first control circuit and a pixel circuit. FIG. 10A is a view illustrating the distribution of thickness unevenness in a liquid crystal layer. FIG. 10B is a diagram showing the voltage distribution and voltage correction width required to correct the light modulation characteristics of a typical spatial light modulator. FIG. 10C is a diagram explaining the first correction according to the first embodiment of the present disclosure. FIG. 10D is a diagram showing the voltage distribution and voltage correction width required to correct the light modulation characteristics of a liquid crystal layer after the first correction. FIG. 11 is a characteristic diagram showing the relationship between pixel pitch and diffraction angle. FIG. 12 is a planar schematic diagram showing an example configuration of multiple pixel electrodes and counter electrodes of the spatial light modulator shown in FIG. 1. FIG. 13 is a block diagram showing a schematic configuration of a display device including the spatial light modulator according to the first embodiment of the present disclosure. FIG. 14 is a planar schematic diagram showing an example configuration of multiple pixel electrodes and counter electrodes of a spatial light modulator according to a first modification of the present disclosure. FIG. 15 is a planar schematic diagram showing an example configuration of multiple pixel electrodes and counter electrodes of a spatial light modulator according to a second modification of the present disclosure. FIG. 16 is a planar schematic diagram showing an example configuration of multiple pixel electrodes and counter electrodes of a spatial light modulator according to a third modification of the present disclosure. Fig. 17 is a planar schematic diagram showing a configuration example of a plurality of pixel electrodes and a counter electrode of a spatial light modulator according to Modification 4 of the present disclosure. Fig. 18 is a schematic diagram showing a configuration example of a spatial light modulator according to Modification 5 of the present disclosure. Fig. 19 is a schematic diagram showing a configuration example of a spatial light modulator according to Modification 5 of the present disclosure. Fig. 20 is a planar schematic diagram showing a configuration example of a counter electrode of a spatial light modulator according to Modification 5 of the present disclosure.FIG. 21 is an exploded perspective view of a spatial light modulator according to a sixth modification of the present disclosure. FIG. 22 is a cross-sectional schematic diagram illustrating a configuration of a spatial light modulator according to a second embodiment of the present disclosure. FIG. 23 is a cross-sectional schematic diagram illustrating a configuration of a spatial light modulator according to a third embodiment of the present disclosure. FIG. 24A is a diagram illustrating a direct-view display to which a spatial light modulator according to the present disclosure is applied. FIG. 24B is a diagram illustrating a head-mounted display to which a spatial light modulator according to the present disclosure is applied. FIG. 24C is a diagram illustrating a head-up display to which a spatial light modulator according to the present disclosure is applied. FIG. 25A is a diagram illustrating an example configuration of a laser device to which a spatial light modulator according to the present disclosure is applied. FIG. 25B is a diagram illustrating an example configuration of a laser device to which a spatial light modulator according to the present disclosure is applied. FIG. 25C is a diagram illustrating an example of a land shape. FIG. 26A is a diagram illustrating the interior of a vehicle from the rear to the front of the vehicle. FIG. 26B is a diagram illustrating the interior of a vehicle from diagonally rear to diagonally front of the vehicle. FIG. 27A is a front view of a digital camera as an application example of a display device. Fig. 27B is a rear view of the digital camera shown in Fig. 27A. Fig. 28A is an external view of a head-mounted display, which is an application example of the display device. Fig. 28B is an external view of smart glasses, which is an application example of the display device. Fig. 29 is an external view of a TV, which is an application example of the display device. Fig. 30 is an external view of a smartphone, which is an application example of the display device.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The following description is a specific example of the present disclosure, and the present disclosure is not limited to the following aspects. Furthermore, the present disclosure is not limited to the arrangement, dimensions, dimensional ratios, etc. of the components shown in the drawings. The order of description is as follows: 1. First Embodiment (An example of a spatial light modulator having partitions that divide a liquid crystal layer between adjacent segments in a plan view) 2. Modifications 2-1. Modification 1 (Another example of a counter electrode configuration) 2-2. Modification 2 (Another example of a counter electrode configuration) 2-3. Modification 3 (Another example of a counter electrode configuration) 2-4. Modification 4 (Another example of a counter electrode configuration) 2-5. Modification 5 (Another example of a spatial light modulator configuration) 2-6. Modification 6 (Another example of a spatial light modulator configuration) 3. Second Embodiment (An example of a spatial light modulator in which a drive substrate is arranged on the light incident side and a dielectric multilayer film is provided below a counter electrode divided into multiple segments provided on a counter substrate) 4. 5. Third embodiment (Example of spatial light modulator in which the thickness of the counter electrode divided into a plurality of segments is changed in accordance with the unevenness of the gap between the drive substrate and the counter substrate)

[0011] 1. First Embodiment Fig. 1 is a schematic diagram illustrating an example of a cross-sectional configuration of a spatial light modulator (spatial light modulator 1) according to a first embodiment of the present disclosure. Fig. 2 is a schematic diagram of the spatial light modulator 1 illustrated in Fig. 1. The spatial light modulator 1 is a reflective spatial light modulator (SLM) that has a liquid crystal layer 30 between a drive substrate 10 and a counter substrate 20 that are disposed opposite each other, and in which light (incident light L) incident from the counter substrate 20 side is reflected by the drive substrate 10 and emitted from the counter substrate 20, for example.

[0012] [Configuration of Spatial Light Modulator] The spatial light modulator 1 has a liquid crystal layer 30 between a drive substrate 10 and a counter substrate 20 arranged opposite each other. The drive substrate 10 has a pair of opposing surfaces (surfaces 10S1 and 10S2) and includes a plurality of pixel electrodes 13, one for each unit pixel P arranged in an array in the row and column directions. The counter substrate 20 has a pair of opposing surfaces (surfaces 20S1 and 20S2) and includes a counter electrode 22 divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4; see FIG. 4 ) that are larger than the plurality of pixel electrodes 13. The spatial light modulator 1 further has a first control circuit that individually controls the voltages applied to the plurality of pixel electrodes 13 and a second control circuit that individually controls the voltages applied to the counter electrode for each division unit (each of the four segments S1, S2, S3, and S4). In the spatial light modulator 1 of this embodiment, a partition wall 31 is further provided between the drive substrate 10 and the counter substrate 20 and at least partially between the plurality of segments S1, S2, S3, and S4 adjacent to each other in a plan view.

[0013] Here, the drive substrate 10 corresponds to a specific example of a "first substrate" as an embodiment of the present disclosure, and the plurality of pixel electrodes 13 correspond to a specific example of a "plurality of first electrodes" as an embodiment of the present disclosure. The counter substrate 20 corresponds to a specific example of a "second substrate" as an embodiment of the present disclosure, and the counter electrode 22 corresponds to a specific example of a "second electrode" as an embodiment of the present disclosure. The liquid crystal layer 30 corresponds to a specific example of a "liquid crystal layer" as an embodiment of the present disclosure. The partition wall 31 corresponds to a specific example of a "partition wall" as an embodiment of the present disclosure.

[0014] The drive substrate 10 includes, for example, a support substrate 11 made of silicon (Si), a wiring layer 12, a plurality of pixel electrodes 13, a planarization layer 14, and an alignment film 15. The wiring layer 12, the plurality of pixel electrodes 13, the planarization layer 14, and the alignment film 15 are provided in this order on the surface of the support substrate 11 facing the liquid crystal layer 30.

[0015] The wiring layer 12 is provided on the support substrate 11 and includes, for example, a pixel circuit 120 made up of a plurality of transistors that drives the liquid crystal layer 30 for each unit pixel P, a first control circuit, a second control circuit, and the like.

[0016] As described above, a plurality of pixel electrodes 13 are provided for each unit pixel P. The plurality of pixel electrodes 13 generate an electric field E in the liquid crystal layer 30 based on a voltage applied to each of the pixel electrodes 13 from an AC power supply 40. The voltages applied to the plurality of pixel electrodes 13 are individually controlled by a first control circuit.

[0017] The pixel electrodes 13 each have a laminated structure of, for example, a transparent conductive film and a reflective film. Examples of materials for the transparent conductive film include oxide semiconductors called indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), or IGZO (indium gallium zinc oxide). Examples of materials for the reflective film include metal materials with optical reflectivity, such as aluminum (Al), titanium (Ti), copper (Cu), silicon (Si), silver (Ag), or alloys thereof (e.g., Al-Cu alloys and Al-Si alloys).

[0018] The planarization layer 14 is intended to planarize a surface 10S1 of the drive substrate 10 that faces the liquid crystal layer 30. The planarization layer 14 is made of, for example, silicon oxide (SiO ２ ), silicon nitride (Si ３ N ４ ), silicon oxynitride (SiON), SiCN, or the like.

[0019] The alignment film 15 controls the direction (also called orientation) of the liquid crystal molecules 131 contained in the liquid crystal layer 30. The alignment film 15 has an alignment regulating force that aligns the liquid crystal molecules 131 in accordance with the anisotropy of the molecules of the constituent material. By making the directions of the alignment regulating forces of the alignment film 15 and an alignment film 24 (described later) different from each other, it is possible to generate a twist in the orientation of the multiple liquid crystal molecules 131 in the liquid crystal layer 30.

[0020] The material of the alignment film 15 is, for example, silicon oxide (SiO ２ ), diamond-like carbon or aluminum oxide (Al ２ O３ The alignment film 15 can be formed by using, for example, a vapor deposition method.

[0021] The counter substrate 20 includes, for example, a light-transmitting support substrate 21, a counter electrode 22, a planarization layer 23, and an alignment film 24. The counter electrode 22, the planarization layer 23, and the alignment film 24 are provided in this order on the surface of the support substrate 21 facing the liquid crystal layer 30.

[0022] As described above, the counter electrode 22 is divided into a plurality of segments (for example, four segments S1, S2, S3, and S4) that are larger than the plurality of pixel electrodes 13. In this embodiment, each division of the counter electrode 22 is referred to as a "segment." The counter electrodes 22 generate an electric field E in the liquid crystal layer 30 based on a voltage applied to each of the counter electrodes 22 from an AC power supply 40. The voltage applied to the counter electrode 22 is controlled individually for each segment by a second control circuit.

[0023] The counter electrode 22 is made of, for example, a transparent conductive film, and transmits incident light L and light reflected by the plurality of pixel electrodes 13. The counter electrode 22 can be made of, for example, ITO. Alternatively, the counter electrode 22 may be formed using a high-temperature polysilicon substrate. This allows the counter electrode 22 to be divided into any size and shape on a two-dimensional plane.

[0024] The planarization layer 23 is intended to planarize the surface 20S1 of the counter substrate 20 that faces the liquid crystal layer 30. The planarization layer 23 is made of, for example, SiO ２ , Si ３ N ４ , SiON, SiCN or the like.

[0025] The alignment film 24, like the alignment film 15, controls the alignment of the liquid crystal molecules 131 contained in the liquid crystal layer 30, and has an alignment control force that aligns the liquid crystal molecules 131 according to the anisotropy of the molecules of the constituent material. Examples of materials for the alignment film 24 include silicon oxide (SiO ２ ), diamond-like carbon or aluminum oxide (Al ２ O ３The alignment film 24 can be formed by using, for example, a vapor deposition method.

[0026] The liquid crystal layer 30 is composed of liquid crystals driven in, for example, VA (Vertical Alignment) mode, TN (Twisted Nematic) mode, ECB (Electrically Controlled Birefringence) mode, FFS (Fringe Field Switching) mode, or IPS (In Plane Switching) mode. The liquid crystal layer 30 is sealed by, for example, a thermosetting or UV-curable sealant commercially available for liquid crystal displays, which bonds the drive substrate 10 and the counter substrate 20 together. The liquid crystal layer 30 is formed by bonding the drive substrate 10 and the counter substrate 20 together with the sealant, injecting liquid crystal, and then sealing with, for example, a UV-curable sealant. Alternatively, the liquid crystal layer 30 may be fabricated using, for example, an ODF (One Drop Fill) process. A video voltage is supplied to the liquid crystal layer 30 via a plurality of pixel electrodes 13A and a counter electrode 22.

[0027] When no electric field E is generated in the liquid crystal layer 30, i.e., when no voltage is applied to the pixel electrodes 13 and the counter electrode 22, the liquid crystal molecules 131 are aligned according to the alignment restricting forces of the alignment films 15 and 24. At this time, the angle (θ) formed between the liquid crystal molecules 131 and the alignment film 15 (or the alignment film 24) is also called the pretilt angle (see FIG. 2).

[0028] When a voltage is applied to the pixel electrodes 13 and the counter electrode 22, the orientation of the liquid crystal molecules 131 changes due to the electric field E generated in the liquid crystal layer 30. FIG. 3A illustrates the dielectric properties of the liquid crystal molecules 131. The liquid crystal molecules 131 are represented by ellipsoids as shown in FIG. 3A. The tilt of the major and minor axes of the liquid crystal molecules 131 (i.e., the orientation) changes due to the electric field E applied to the liquid crystal molecules 131. The property of changing the orientation due to the applied electric field E is also called dielectric anisotropy.

[0029] The liquid crystal molecules 131 include liquid crystal molecules 131a (positive liquid crystals) whose major axes are parallel to the electric field direction, and liquid crystal molecules 131b (negative liquid crystals) whose minor axes are parallel to the electric field direction. The dielectric anisotropy of the liquid crystal molecules 131a is also called positive dielectric anisotropy. The dielectric anisotropy of the liquid crystal molecules 131b is also called negative dielectric anisotropy.

[0030] 3B illustrates the optical properties of the liquid crystal molecules 131. The refractive index of the liquid crystal molecules 131 changes depending on their orientation with respect to the linearly polarized light Lp. FIG. 3B illustrates a liquid crystal molecule 131c whose major axis is perpendicular to the direction of propagation of the linearly polarized light Lp, and a liquid crystal molecule 131d whose major axis is parallel to the direction of propagation of the linearly polarized light Lp. The liquid crystal molecules 131c and 131d each have a different refractive index n ｅ , n ０ The refractive index n of the liquid crystal molecules 131c ｅ is the refractive index n of the liquid crystal molecule 131d ０ The property in which the refractive index changes depending on the orientation of the liquid crystal molecules is also called refractive index anisotropy.

[0031] The spatial light modulator 1 modulates the phase, amplitude, and polarization state of light by utilizing the properties of the liquid crystal molecules 131 shown in Figures 3A and 3B. As described above, the spatial light modulator 1 has a structure in which a liquid crystal layer 30 is sandwiched between a plurality of pixel electrodes 13 and a counter electrode 22, and changes the orientation state of the plurality of liquid crystal molecules 131 by applying a voltage to the liquid crystal layer 30. When light passes through the liquid crystal layer 30, the phase, amplitude, and polarization state change, and the degree of these changes varies depending on the orientation of the plurality of liquid crystal molecules 131. This enables the spatial light modulator 1 to change the state of light by applying a voltage via the plurality of pixel electrodes 13 and the counter electrode 22.

[0032] The state of light that the spatial light modulator 1 changes is determined by the orientation direction of the multiple liquid crystal molecules 131 relative to the polarization direction of the incident light. When the incident light is linearly polarized, the phase of the light can be modulated by aligning the polarization direction of the incident light with the orientation direction parallel to the polarization direction of the incident light. By setting the angle at 45°, the polarization state of the light can be modulated. Furthermore, by modulating the polarization state with a polarizing plate installed downstream, the amplitude of the light can be modulated.

[0033] The spatial light modulator 1 can switch whether or not to change the state of light for each unit pixel P by switching whether or not to apply a voltage to each of the plurality of pixel electrodes 13. When the spatial light modulator 1 modulates the phase of light, the phase difference between the light emitted from the unit pixel P to which no voltage is applied and the light emitted from the unit pixel P to which a voltage is applied is also called a phase shift.

[0034] 4 is a schematic diagram illustrating an example of the configuration of a plurality of pixel electrodes 13 and a counter electrode 22. The drive substrate 10 has a pixel array section 100A in which a plurality of unit pixels P are arranged, for example, in the row direction (X-axis direction) and the column direction (Y-axis direction). The counter electrode 22, which is arranged opposite the plurality of pixel electrodes 13, is divided into, for example, four segments S1, S2, S3, and S4, each of which is larger than the plurality of pixel electrodes 13, as described above. In other words, the pixel array section 100A is divided into four segments S1, S2, S3, and S4 as shown in FIG. 4, and each unit pixel P is arranged in one of the segments S1, S2, S3, and S4.

[0035] In the spatial light modulator 1 of this embodiment, as will be described in detail later, as a first correction, a correction voltage that roughly adjusts the light modulation characteristics caused by in-plane nonuniformity is applied to the opposing electrode 22 divided into, for example, four segments S1, S2, S3, and S4, and as a second correction, a correction voltage that finely adjusts the light modulation characteristics caused by in-plane nonuniformity remaining after the first correction is applied to each of the multiple pixel electrodes 13 provided for each unit pixel P.

[0036] When different correction voltages are applied to the segmented counter electrode 22, a fringe field Ef is generated between adjacent segments, which may cause unwanted rotation of the liquid crystal molecules 131. For example, as shown in Figure 5A, if a fringe field Ef is generated in a direction parallel to the alignment direction of the liquid crystal molecules 131, which have positive dielectric anisotropy and are homogeneously aligned (horizontally aligned) with respect to the counter substrate 20, the liquid crystal molecules 131 are not easily affected by the fringe field Ef and are unlikely to rotate. On the other hand, as shown in Figure 5B, if a fringe field Ef is generated in a direction perpendicular to the alignment direction of the liquid crystal molecules 131, which have positive dielectric anisotropy and are homogeneously aligned (horizontally aligned) with respect to the counter substrate 20, the liquid crystal molecules 131 are affected by the fringe field Ef and rotate, for example, in the direction of the arrow, causing crosstalk.

[0037] As described above, the spatial light modulator 1 of this embodiment has the partition wall 31 provided between the drive substrate 10 and the counter substrate 20. The partition wall 31 shields the fringe electric field Ef generated between the counter electrode 22 divided into a plurality of segments adjacent in the XY plane direction, thereby suppressing unnecessary rotation of the liquid crystal molecules 131.

[0038] The partition walls 31 are provided between the segments S1, S2, S3, and S4 adjacent to each other in the XY plane. As described above, crosstalk occurs when a fringe electric field Ef is generated in a direction perpendicular to the alignment direction of the liquid crystal molecules 131. Therefore, it is preferable that the partition walls 31 are provided in a direction at least parallel to the alignment direction of the liquid crystal molecules 131, as shown in FIG. 6, for example. This makes it possible to suppress unnecessary rotation of the liquid crystal molecules 131 due to the fringe electric field Ef.

[0039] 1, the partition wall 31 is preferably provided to penetrate the liquid crystal layer 30 so that both end faces thereof contact the drive substrate 10 and the counter substrate 20. However, this is not limited thereto, and the partition wall 31 may extend from the counter substrate 20 toward the drive substrate 10, for example, as shown in FIG. 7A, with a gap between the drive substrate 10 and its end face (surface 31S1) facing the drive substrate 10. Alternatively, as shown in FIG. 7B, the partition wall 31 may extend from the drive substrate 10 toward the counter substrate 20, with a gap between the counter substrate 20 and its end face (surface 31S2) facing the counter substrate 20. In either case, a certain shielding effect of the fringe electric field Ef can be obtained.

[0040] 1 and 7A and 7B show an example in which the partition walls 31 are provided on the alignment films 15 and 24, but this is not limiting. The partition walls 31 may be provided on the planarization layer 23 as shown in FIGS. 7C and 7D. In this case, the alignment film 24 may be provided between the partition walls 31, for example, as shown in FIG. 7C, or may be provided so as to cover the side and end faces of the partition walls 31, for example, as shown in FIG. 7D. While FIGS. 7C and 7D show an example in which the partition walls 31 are provided on the opposing substrate 20 side, the same applies when the partition walls 31 are provided on the driving substrate 10 side. Furthermore, when the partition walls 31 are provided as in this embodiment, the alignment films 15 and 24 can be omitted because the light distribution regulating force of the partition walls 31 can distribute the light distribution of the liquid crystal molecules 131.

[0041] The partition wall 31 is made of, for example, SiO ２ The partition walls 31 can be formed using a dielectric material such as acrylic resin, liquid crystal polymer, or the like. The material for the partition walls 31 is not limited to the above materials, and any material can be used as long as it can be microfabricated and does not react with the liquid crystal molecules 131 when it comes into contact with them, and can be either an inorganic material or an organic material. In addition, in consideration of the shielding effect of the fringe electric field Ef, the partition walls 31 preferably have a low dielectric constant. Therefore, the partition walls 31 may have a hollow structure or a porous structure with voids inside.

[0042] [Overall Configuration of Spatial Light Modulator] Figure 8 shows the overall configuration of the spatial light modulator 1. The spatial light modulator 1 includes a pixel array section 100A, a segment voltage control section 51, a pixel voltage generation section 52, an H shift register 53, a V shift register 54, and a frame switching pulse generation circuit 55. Each of the plurality of unit pixels P has a pixel circuit 120 and liquid crystal molecules 131. The spatial light modulator 1 can control the orientation of the liquid crystal molecules 131 for each of the plurality of pixel electrodes 13.

[0043] In this embodiment, one row of unit pixels P arranged in the X-axis direction in the pixel array section 100A is called a pixel row, and one column of unit pixels P arranged in the Y-axis direction is called a pixel column.

[0044] The segment voltage control unit 51 is a circuit that controls the voltage for each segment (e.g., four segments S1, S2, S3, and S4) of the counter electrode 22. The segment voltage control unit 51 controls the voltage for each of the segments S1, S2, S3, and S4 individually. The segment voltage control unit 51 corresponds to a specific example of a "second control circuit" according to an embodiment of the present disclosure.

[0045] The pixel voltage generating unit 52 individually generates voltages to be applied to the plurality of pixel electrodes 13. The H shift register 53 controls the sequential selection of the plurality of pixel columns. The V shift register 54 controls the sequential selection of the plurality of pixel rows.

[0046] The H shift register 53 and the V shift register 54 select one unit pixel P from the plurality of unit pixels P. A voltage generated by the pixel voltage generation unit 52 is applied to the pixel electrode 13 provided in the selected unit pixel P. The pixel voltage generation unit 52, the H shift register 53, and the V shift register 54, which individually control the voltages of the plurality of pixel electrodes 13, correspond to a specific example of a “first control circuit” according to an embodiment of the present disclosure.

[0047] 9 shows a detailed configuration example of the first control circuit and the pixel circuit 120. As shown in FIG. 9, the pixel voltage generation unit 52 supplies a pixel voltage to be displayed in each unit pixel P to the pixel voltage line Vcom2. The pixel array unit 100A has a plurality of vertical signal lines VSL arranged in the X-axis direction, each extending in the Y-axis direction. A switch 121 is connected to each vertical signal line VSL. Each switch 121 is turned on when a pulse signal is output from the H shift register 53, and supplies the pixel voltage of the pixel voltage line Vcom2 to the corresponding vertical signal line VSL.

[0048] Each of the pixel circuits 120 includes a pixel transistor 122. The pixel transistor 122 is, for example, an NMOS (N-channel Metal-Oxide-Semiconductor) transistor. The pixel transistor 122 is also called a TFT (Thin Film Transistor). The source of the pixel transistor 122 is connected to one end of the switch 121 and the frame switching pulse generation circuit 55 via the vertical signal line VSL. A voltage is input to the gate of the pixel transistor 122 from the V shift register 54. The drain of the pixel transistor 122 is connected to one end of the liquid crystal molecule 131. The pixel transistor 122 is turned on when, for example, a high-level voltage is input from the V shift register 54, and supplies the pixel voltage of the corresponding vertical signal line VSL to the plurality of pixel electrodes 13.

[0049] The H shift register 53 sequentially turns on a plurality of switches 121. When the H shift register 53 turns on the switches 121, the pixel voltages generated by the pixel voltage generating units 52 for the respective unit pixels P in the pixel column are supplied to the vertical signal lines VSL via the switches 121. When the V shift register 54 drives the pixel transistors 122, the pixel voltages of the vertical signal lines VSL are applied to the liquid crystal molecules 131 via the pixel transistors 122.

[0050] The V shift register 54 sequentially drives a plurality of pixel electrode groups arranged in the Y-axis direction. More specifically, a different horizontal signal line HSL extends from the V shift register 54 for each pixel row. The V shift register 54 applies a high-level voltage to the gates of the pixel transistors 122 of all pixel circuits 120 connected to the same pixel row via the horizontal signal line HSL for each pixel row. The pixel voltage generation unit 52 and the H shift register 53 supply a pixel voltage to one pixel circuit 120 of all pixel circuits 120 connected to the pixel row driven by the V shift register 54 via the corresponding vertical signal line VSL.

[0051] Specifically, the V shift register 54 sequentially supplies a high-level voltage to a plurality of pixel rows arranged in the Y-axis direction. By supplying a high-level voltage to one pixel row, the V shift register 54 drives the pixel transistors 122 of all pixel circuits 120 included in that pixel row.

[0052] The frame switching pulse generating circuit 55 controls resetting of all unit pixels P in the pixel array section 100A at the timing of frame switching.

[0053] A state in which one unit pixel P belongs to a pixel column whose switch 121 is turned on and at the same time a high-level voltage is applied to the pixel transistor 122 is called a selected state. The H shift register 53 and the V shift register 54 select the multiple unit pixels P at different timings. The pixel voltage generation unit 52 switches the voltage level of the pixel voltage depending on the timing at which the multiple unit pixels P are selected, thereby supplying a voltage corresponding to the unit pixel P to the vertical signal line VSL.

[0054] As described above, the first control circuit can individually control the voltage supplied to each of the plurality of pixel electrodes 13. The method of controlling the voltage applied to the liquid crystal layer 30 for each unit pixel P is also called an active method.

[0055] A different segment voltage line Vcom1 extends from the segment voltage control unit 51 for each of the segments S1, S2, S3, and S4. The segment voltage control unit 51 supplies a segment voltage to each of the segments S1, S2, S3, and S4 of the counter electrode 22 individually via the segment voltage line Vcom1. The segment voltage control unit 51 has a transistor (not shown) for each of the segments S1, S2, S3, and S4, and by controlling the gate voltage of each transistor, a signal is output from the source or drain of each transistor, thereby controlling the corresponding segment voltage.

[0056] The frame switching pulse generating circuit 55 inputs a voltage for resetting each of the plurality of pixel electrodes 13 to the reset voltage line Psig at the timing of frame switching.

[0057] As shown in FIG. 2 and other figures, the spatial light modulator 1 can change the phase, amplitude, polarization state, etc. of light by applying a voltage to the liquid crystal molecules 131. In addition, the spatial light modulator 1 can correct light modulation characteristics caused by in-plane nonuniformities, such as uneven thickness, of the liquid crystal layer 30, by correcting the voltage applied to the liquid crystal molecules 131. The spatial light modulator 1 can perform a correction (first correction) for each segment of the counter electrode 22 and a correction (second correction) for each unit pixel P. The first correction is performed by controlling the segment voltages output by the segment voltage control unit 51, which is the second control circuit, for each segment of the counter electrode 22. The second correction is performed by controlling the pixel voltages output by the pixel voltage generation unit 52, which constitutes the first control circuit, for each of the plurality of pixel electrodes 13. The first correction is a correction for coarsely adjusting the light modulation characteristics caused by in-plane nonuniformities, such as uneven thickness, of the liquid crystal layer 30, while the second correction is a correction for finely adjusting the light modulation characteristics.

[0058] The size (area) of each of the segments S1, S2, S3, and S4 of the counter electrode 22 is larger than the size (area) of the plurality of pixel electrodes 13. For this reason, the transistors of each of the segments S1, S2, S3, and S4 provided in the segment voltage control unit 51 have a larger area and higher voltage resistance than the pixel transistors 122 of each of the plurality of pixel electrodes 13. The voltage correction width of the counter electrode 22 controlled by the second control circuit is larger than the voltage correction width of the pixel voltages applied to the plurality of pixel electrodes 13 by the first control circuit.

[0059] 10A to 10D illustrate the correction of light modulation characteristics caused by in-plane non-uniformity such as uneven thickness of the liquid crystal layer 30. For ease of explanation, an example is used in which the counter electrode 22 is divided into a grid pattern, for example, into 12 segments S1 to S12 of 4 rows and 3 columns.

[0060] The thickness unevenness of the liquid crystal layer 30 is equivalent to, for example, the variation in the gap (also called gap unevenness or gap distribution) between the drive substrate 10 and the counter substrate 20. The gap between the drive substrate 10 and the counter substrate 20 tends to be thicker (larger) toward the center of the liquid crystal layer 30 and thinner (smaller) toward the edge, as shown in Fig. 10A for example.

[0061] 10B shows the voltage distribution and voltage correction width Vr1 required to correct the light modulation characteristics of a typical spatial light modulator. For example, in a typical spatial light modulator having a common counter electrode for all pixel electrodes in a pixel array, the light modulation characteristics resulting from in-plane nonuniformities such as uneven thickness of the liquid crystal layer 30 are corrected solely by the voltage applied to each pixel electrode. In this case, it is necessary to control the voltage applied to each pixel electrode by the difference (voltage correction width Vr1) between the minimum and maximum voltage values ​​at which modulation occurs in the pixel array.

[0062] In contrast to this, in the spatial light modulator 1 of this embodiment, as described above, the counter electrode 22 is divided into segments larger than the plurality of pixel electrodes 13, and the voltage value is corrected for each group of the plurality of unit pixels P arranged in each segment.

[0063] For example, if the liquid crystal layer 30 has gap unevenness as shown in FIG. 10A , the counter electrode 22 is divided into a plurality of segments (e.g., 12 segments S1 to S12 arranged in 4 rows and 3 columns) according to the gap distribution, as shown in FIG. 10C . In the spatial light modulator 1 of this embodiment, first, as a first correction, the light modulation characteristics caused by in-plane nonuniformity are roughly adjusted for each segment. Next, as a second correction, the light modulation characteristics caused by in-plane nonuniformity remaining after the first correction are finely adjusted for each of the plurality of pixel electrodes 13. This corrects the light modulation characteristics caused by in-plane nonuniformity, such as uneven thickness of the liquid crystal layer 30.

[0064] 10A, as a first correction, a higher voltage (e.g., a voltage of 4) is applied to two segments S6 and S7 located in the center of the liquid crystal layer 30 and having the largest gap unevenness among the 12 segments S1 to S12 arranged in 4 rows and 3 columns shown in FIG. 10C. A lower voltage (e.g., a voltage of 2) is applied to four segments S1, S4, S9, and S12 located at the four corners of the liquid crystal layer 30 and having the smallest gap unevenness among the 12 segments S1 to S12 arranged in 4 rows and 3 columns shown in FIG. A voltage between the voltage applied to segments S6 and S7 and the voltage applied to segments S1, S4, S9, and S12 (e.g., a voltage of voltage value 3) is applied to segments S2, S3, S5, S8, S, S10, and S11 located between the four corners of the liquid crystal layer 30, including gap unevenness between segments S6 and S7 and segments S1, S4, S9, and S12. In the first correction, for example, a voltage of voltage correction width Vr1 shown in FIG. 10B is applied to each of segments S1 to S12 of the counter electrode 22.

[0065] 10D shows the voltage distribution and voltage correction width Vr2 required to correct the light modulation characteristics of the liquid crystal layer 30 after the first correction. In the second correction, the light modulation characteristics caused by the in-plane nonuniformity remaining after the first correction are corrected, so the voltage correction width required to correct the light modulation characteristics caused by the in-plane nonuniformity remaining in the liquid crystal layer 30 after the first correction is the width obtained by subtracting the voltage correction width performed in the first correction from the voltage correction width Vr1 shown in FIG. 10B (for example, the voltage correction width Vr2 shown in FIG. 10D ).

[0066] That is, the first control circuit individually adjusts the pixel voltages to be applied to the plurality of pixel electrodes 13 based on the voltage control of the counter electrode 22 for each of the segments S1 to S12 by the first correction. Specifically, the pixel voltage generation unit 52 applies a voltage according to the voltage distribution shown in FIG. 10D to each pixel electrode 13.

[0067] In this way, in the spatial light modulator 1 of this embodiment, by using the first and second corrections described above in combination, more dynamic and highly accurate correction is realized.

[0068] Fig. 11 shows the relationship between the distance between the centers of adjacent unit pixels P (pixel pitch Pi, see Fig. 2) and the diffraction angle of light. In Fig. 11, the horizontal axis represents the pixel pitch [µm], and the vertical axis represents the diffraction angle [deg] of light passing through the pixel. As shown in Fig. 11, as the pixel pitch decreases, the diffraction angle of light increases logarithmically.

[0069] If the diffraction angle of light passing through the unit pixel P is increased, the range in which light modulation by the spatial light modulator 1 can be controlled is expanded, and the performance of the spatial light modulator 1 can be improved.

[0070] In the spatial light modulator 1 of this embodiment, the first correction involves roughly adjusting the light modulation characteristics resulting from in-plane nonuniformity for each segment using the counter electrode 22, which is divided into segments larger than the plurality of pixel electrodes 13. Then, the second correction involves finely adjusting the light modulation characteristics resulting from in-plane nonuniformity remaining after the first correction for each of the plurality of pixel electrodes 13. This reduces the voltage correction range (voltage correction range Vr2) of the voltage applied to the plurality of pixel electrodes 13 in the spatial light modulator 1 of this embodiment compared to the voltage correction range (e.g., voltage correction range Vr1) of the voltage applied to each pixel electrode in a typical spatial light modulator having a common counter electrode for all of the plurality of pixel electrodes in the pixel array section, as described above. This allows for the use of small transistors with low voltage resistance for the pixel transistors 122 that control the voltage of each of the plurality of pixel electrodes 13, thereby enabling the reduction of the unit pixel P and the pixel pitch Pi. This also improves the performance of the spatial light modulator 1.

[0071] 12 is a schematic diagram showing another example of the configuration of the plurality of pixel electrodes 13 and the counter electrode 22 of the spatial light modulator 1 of this embodiment. The counter electrode 22 shown in FIG. 12 is divided into six segments S1, S2, S3, S4, S5, and S6 in a grid pattern. The counter electrode 22 may also be divided into a grid pattern as shown in FIG. 10C and FIG. 12. However, while this has the advantage of being easier to design and manufacture than the counter electrode 22 shown in FIG. 4, it also has the problem of a diffraction pattern resulting from the division appearing in the light output from the spatial light modulator 1.

[0072] 13 shows a schematic configuration of a display system including the spatial light modulator 1 of this embodiment. The display system includes a display device 2 and a host device 61. The display device 2 includes a display unit 62, a display controller 63, a timing controller 64, and an interface (I / F) unit 65.

[0073] The display unit 62 is an application example of the spatial light modulator 1. Specifically, the display unit 62 has a pixel array unit 100A, a gate driver 621, and a source driver 622. The gate driver 621 has a function similar to that of the V shift register 54 in FIG. 8. The source driver 622 has a function similar to that of the pixel voltage generation unit 52 and the H shift register 53.

[0074] The display controller 63 has an H logic unit 631 and a V logic unit 632. The H logic unit 631 controls the source driver 622 to generate pixel signals that cause the pixel array unit 100A to output optical signals based on image data, which will be described later, and supplies the pixel signals to the source driver 622. The V logic unit 632 generates signals that control the gate driver 621 and supplies the signals to the gate driver 621.

[0075] The timing controller 64 includes a clock generator 641 , a timing generator 642 , and an image processing unit 643 .

[0076] The clock generator 641 generates a vertical synchronization clock and a horizontal synchronization clock for the display unit 62 and supplies them to the V logic unit 632. The timing generator 642 generates a signal that controls the operation timing of the display controller 63 and supplies it to the display controller 63. The image processing unit 643 performs various types of image processing on image data input from the host device 61 via the I / F unit 65, and supplies the processed image data to the H logic unit 631. The specific content of the image processing performed by the image processing unit 643 is not important. The image data supplied to the H logic unit 631 includes a plurality of pixel data that are supplied to a plurality of pixels.

[0077] The I / F unit 65 includes an image I / F unit 651 , a clock control unit 652 , an H / V synchronization unit 653 , and a data S / P conversion unit 654 .

[0078] The image I / F unit 651 receives image data transmitted from the host device 61. The image data is serial digital data. The clock control unit 652 generates a clock that matches the display frequency of the display unit 62 and supplies it to the clock generator 641. The H / V synchronization unit 653 determines the horizontal synchronization timing and vertical synchronization timing of the display device 2 and transmits them to the timing generator 642. The data S / P conversion unit 654 converts the image data into parallel data and supplies it to the image processing unit 643.

[0079] The host device 61 sends image data and display control signals to the image I / F unit 651. The host device 61 does not necessarily have to be located near the display device 2. For example, the host device 61 may be located at a location remote from the display device 2 and transmit the image data and display control signals to the display device 2 via a wired or wireless network line.

[0080] 13 is a device that sends a video signal to the display device 2, and is a computer, a camera, a TV, etc. The host device 61 outputs a video signal to the display device 2.

[0081] When the spatial light modulator 1 is applied to a display device 2, the display device 2 may have a color filter. The color filter converts the wavelength of light transmitted through the liquid crystal layer 30 of the spatial light modulator 1 for each color pixel. The color filter is disposed, for example, on the opposing substrate 20 side of the spatial light modulator 1.

[0082] [Operations and Effects] In the spatial light modulator 1 of this embodiment, the partition wall 31 is provided between the drive substrate 10 and the counter substrate 20 which are arranged opposite each other with the liquid crystal layer 30 in between.

[0083] The drive substrate 10 has, for example, a plurality of pixel electrodes 13 arranged in the row and column directions, and the counter substrate 20 has a counter electrode 22 divided into a plurality of segments larger than the plurality of pixel electrodes 13. The plurality of pixel electrodes 13 and the plurality of divided counter electrodes 22 are each connected to a control circuit (a first control circuit and a second control circuit). A correction voltage is applied individually to each segment of the counter electrode 22 as a first correction, coarsely adjusting the light modulation characteristics due to in-plane nonuniformity. A correction voltage is applied individually to each of the plurality of pixel electrodes 13 as a second correction, finely adjusting the light modulation characteristics due to in-plane nonuniformity remaining after the first correction. This allows the use of small transistors with low voltage resistance for the pixel transistors 122 that control the voltages of the plurality of pixel electrodes 13. This allows the pixel pitch Pi to be reduced along with the unit pixel P. Furthermore, the performance of the spatial light modulator 1 can be improved.

[0084] The partition walls 31 are provided at least partially between adjacent segments of the counter electrode, which is divided into a plurality of segments, in a plan view, thereby blocking the fringe electric field Ef generated between the adjacent segments, thereby making it possible to suppress unnecessary rotation of the liquid crystal molecules 131.

[0085] As described above, in this embodiment, it is possible to provide a spatial light modulator 1 having high definition and excellent light modulation characteristics.

[0086] Next, second and third embodiments, modifications 1 to 6, and application examples of the present disclosure will be described. Note that components similar to those of the spatial light modulator 1 in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted where appropriate.

[0087] 2. Modifications (2-1. Modification 1) Fig. 14 is a schematic diagram illustrating an example of the configuration of a plurality of pixel electrodes 13 and a counter electrode 22 of a spatial light modulator (spatial light modulator 1A) according to Modification 1 of the present disclosure. In the first embodiment described above, the counter electrode 22 is divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4) along the boundaries between the plurality of pixel electrodes 13 arranged in the row and column directions. However, the present invention is not limited to this. For example, as shown in Fig. 14, the counter electrode 22 may be divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4) regardless of the boundaries between the plurality of pixel electrodes 13 arranged in the row and column directions.

[0088] In the spatial light modulator 1A of this modification, there are pixel electrodes 13 that span two or more segments. Light reflected by pixel electrodes 13 that span multiple segments becomes noise light. However, when the spatial light modulator 1A is used as a diffraction element, the light reflected by pixel electrodes 13 that span two or more segments simply becomes unnecessary light and does not significantly affect the performance of the spatial light modulator 1A.

[0089] In this way, in the spatial light modulator 1A of this modification, the counter electrode 22 is divided into a plurality of segments (for example, four segments S1, S2, S3, and S4) regardless of the boundaries between the plurality of pixel electrodes 13 arranged in the row and column directions. Even with this configuration, the same effects as in the first embodiment can be obtained.

[0090] Furthermore, in the spatial light modulator 1A of this modification, highly accurate alignment between the plurality of pixel electrodes 13 and the counter electrode 22 is not required, which simplifies the design and fabrication of the spatial light modulator 1A.

[0091] (2-2. Modification 2) FIG. 15 is a schematic diagram illustrating an example of the configuration of a plurality of pixel electrodes 13 and a counter electrode 22 of a spatial light modulator (spatial light modulator 1B) according to Modification 2 of the present disclosure. In the first embodiment described above, the counter electrode 22 is divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4) along the boundaries of a plurality of pixel electrodes 13 arranged in the row and column directions, but this is not limiting. For example, as shown in FIG. 15, the counter electrode 22 may be divided into a plurality of segments (e.g., five segments S1, S2, S3, S4, and S5) in accordance with variations in the gap between the drive substrate 10 and the counter substrate 20.

[0092] In the spatial light modulator 1B of this modified example, the counter electrode 22 is divided into a plurality of segments (for example, five segments S1, S2, S3, S4, and S5) in accordance with variations in the gap between the drive substrate 10 and the counter substrate 20. Even with this configuration, the same effects as those of the first embodiment can be obtained.

[0093] Furthermore, in the spatial light modulator 1B of this modified example, it is possible to optimize the first correction, which controls the applied voltage for each segment. In other words, it is not necessary to divide the counter electrode 22 into more segments than necessary. Furthermore, because the counter electrode 22 is divided into multiple segments centered around the location where the gap between the drive substrate 10 and the counter substrate 20 varies greatly, the first correction can function effectively. In this specification, the optimization of the first correction is sometimes referred to as the optimization of the correction resolution. By optimizing the correction resolution, it is possible to reduce unnecessary diffracted light and improve the accuracy of the light modulated by the spatial light modulator 1B.

[0094] (2-3. Modification 3) Figure 16 is a schematic diagram illustrating an example of the configuration of a plurality of pixel electrodes 13 and a counter electrode 22 of a spatial light modulator (spatial light modulator 1C) according to Modification 3 of the present disclosure. In the first embodiment described above, the counter electrode 22 is divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4) along the boundaries of a plurality of pixel electrodes 13 arranged in the row and column directions, but this is not limiting. The counter electrode 22 may also be divided randomly, for example, as shown in Figure 16.

[0095] In this way, in the spatial light modulator 1C of this modification, the counter electrode 22 is randomly divided, which makes it possible to reduce unnecessary diffracted light, and therefore, with this configuration as well, similar effects to those of the first embodiment can be obtained, as with the first modification.

[0096] (2-4. Modification 4) FIG. 17 is a schematic diagram illustrating an example of the configuration of a plurality of pixel electrodes 13 and a counter electrode 22 of a spatial light modulator (spatial light modulator 1D) according to Modification 4 of the present disclosure. In the first embodiment described above, the counter electrode 22 is divided into a plurality of segments (e.g., four segments S1, S2, S3, and S4) along the boundaries of a plurality of pixel electrodes 13 arranged in the row and column directions. However, the present invention is not limited to this. The counter electrode 22 may be divided into a non-periodic pattern. FIG. 17 illustrates an example in which the counter electrode 22 is divided according to a Penrose tile, which is a non-periodic arrangement.

[0097] In this way, in the spatial light modulator 1D of this modification, the counter electrode 22 is divided non-periodically, which makes it possible to reduce unnecessary diffracted light, and therefore, with this configuration as well, similar effects to those of the first embodiment can be obtained, as with the first modification.

[0098] (2-5. Modification 5) Fig. 18 shows an example of the configuration of a spatial light modulator (spatial light modulator 3A) according to Modification 5 of the present disclosure. Fig. 19 shows another example of the configuration of a spatial light modulator (spatial light modulator 3B) according to Modification 5 of the present disclosure.

[0099] A resonant structure can be applied to the spatial light modulators (spatial light modulators 1, 1A-1D) described in the first embodiment and modifications 1 to 4. Examples of resonant structures include a metasurface structure and a Fabry-Perot structure. Conventional spatial light modulators incorporating a resonant structure can significantly improve the amount of phase modulation. However, a resonant structure can produce abrupt phase changes with respect to the applied voltage, and slight in-plane nonuniformity can significantly change the resonance conditions, potentially resulting in significant fluctuations in the light modulation characteristics. In contrast, the spatial light modulators (spatial light modulators 1, 1A-1D) according to the first embodiment and modifications 1 to 4 perform coarse adjustments to control the applied voltage for each segment of the counter electrode 22, followed by fine adjustments to control the pixel voltage applied to each pixel electrode 13. This allows for accurate correction of light modulation characteristics resulting from in-plane nonuniformity, even for spatial light modulators with a resonant structure (e.g., spatial light modulators 3A and 3B).

[0100] The spatial light modulator 3A shown in Figure 18 has a metasurface structure. As shown in Figure 18, the metasurface structure has microstructures 16 provided on a surface in contact with the liquid crystal layer 30, and arbitrarily controls the reflection direction, reflectance, refraction direction, refractive index, diffraction direction, or absorption degree of light incident on this surface. The microstructures 16 are provided on one or both of a pair of opposing surfaces of the liquid crystal layer 30, which are opposed to the drive substrate 10 and the counter substrate 20 of the liquid crystal layer 30, respectively. By optimizing at least one of the shape and size of the microstructures 16, it becomes possible to arbitrarily adjust the phase modulation amount of the spatial light modulator 1 (e.g., a spatial light modulator).

[0101] The spatial light modulator 3B shown in FIG. 19 has a Fabry-Perot structure. Specifically, the liquid crystal layer 30 shown in FIG. 19 includes a multilayer reflective film 17 and a multilayer reflective film 26. The multilayer reflective film 17 and the multilayer reflective film 26 are disposed on a pair of surfaces of the liquid crystal layer 30 facing the drive substrate 10 and the counter substrate 20, respectively. FIG. 19 illustrates an example in which the multilayer reflective film 17 is disposed on the side of the pixel electrodes 13, and the multilayer reflective film 26 is disposed on the side of the counter electrode 22. The multilayer reflective film 17 and the multilayer reflective film 26 reflect light of a predetermined frequency that passes through the liquid crystal layer 30. This causes light to resonate between the multilayer reflective film 17 and the multilayer reflective film 26, thereby increasing the amount of phase modulation. The multilayer reflective film 17 and the multilayer reflective film 26 are, for example, dielectric DBRs (Distributed Bragg Reflectors).

[0102] 18 and 19 can be applied to the opposing electrode 22 described in the first embodiment and modifications 1 to 4. This allows the abrupt phase change in the spatial light modulators 3A and 3B caused by in-plane nonuniformity, such as variations in the gap between the drive substrate 10 and the opposing substrate 20, to be corrected by the first and second corrections described above.

[0103] Furthermore, the counter electrode 22 may be divided in accordance with unevenness caused by the resonant structure. Fig. 20 is a schematic diagram showing an example of the configuration of the counter electrode 22 of the spatial light modulators 3A and 3B according to Modification 5 of the present disclosure. The counter electrode 22 shown in Fig. 20 is divided in accordance with, for example, dimensional unevenness of the microstructure of the microstructure 16. The counter electrode 22 of this modification is divided based on, for example, statistically understood dimensional unevenness of the microstructure.

[0104] 20 to the spatial light modulator 3A with a metasurface structure, the correction resolution of the first correction can be optimized. This provides effects such as high-precision correction at the edges of the liquid crystal layer 30 where gap unevenness is large, a reduction in the number of divisions of the counter electrode 22f, and a reduction in unnecessary diffracted light from the spatial light modulator 3A.

[0105] Similarly, the counter electrode 22 divided in accordance with the structural dimensional irregularities of the multilayer reflective film 17 and the multilayer reflective film 26 may be applied to the spatial light modulator 3B having a Fabry-Perot structure.

[0106] In this way, the spatial light modulators 3A and 3B of this modification employ a resonant structure that allows for a large degree of control over the light modulation characteristics. Generally, in a spatial light modulator having a resonant structure, even slight in-plane nonuniformity in the liquid crystal layer significantly changes the resonance conditions. However, in the spatial light modulators 3A and 3B of this modification, the first correction is performed to roughly adjust the light modulation characteristics caused by in-plane nonuniformity, and then the second correction is performed to finely adjust the light modulation characteristics, thereby enabling accurate correction of the light modulation characteristics.

[0107] Furthermore, by employing a resonator structure, the pixel pitch Pi can be further reduced, thereby realizing even higher definition and smaller spatial light modulators 3A and 3B.

[0108] (2-6. Modification 6) FIG. 21 illustrates a configuration example of a spatial light modulator (spatial light modulator 3C) according to Modification 6 of the present disclosure.

[0109] In the first embodiment and modifications 1 to 5, examples have been shown in which the spatial light modulators 1, 1A to 1D, 3A, and 3B are reflective SLMs, but this is not limiting. The spatial light modulator 3C shown in Fig. 21 is a transmissive SLM, and the drive substrate 10 is optically transparent. In the spatial light modulator 3C, the drive substrate 10 is made of, for example, high-temperature polysilicon.

[0110] In the spatial light modulator 3C, for example, light from a predetermined backlight is taken in from the drive substrate 10 side. The light (incident light L) incident from the drive substrate 10 side is modulated by the liquid crystal layer 30 or the like and output from the counter substrate 20. When the spatial light modulator 3C, which is a transmissive SLM, is applied to the display device 2 or the like, a color filter 27 may be arranged on the counter substrate 20 side.

[0111] 22 is a schematic diagram illustrating an example of a cross-sectional configuration of a spatial light modulator (spatial light modulator 4) according to a second embodiment of the present disclosure. The spatial light modulator 4 has a liquid crystal layer 30 between a counter substrate 70 and a drive substrate 80 that are disposed opposite each other, and is, for example, a reflective SLM in which light incident from the drive substrate 80 side (incident light L) is reflected by the counter substrate 70 and emitted from the drive substrate 80 side.

[0112] [Configuration of Spatial Light Modulator] The spatial light modulator 4 has a liquid crystal layer 30 between a counter substrate 70 and a drive substrate 80, which are arranged opposite each other. The counter substrate 70 has a pair of opposing surfaces (surfaces 70S1 and 70S2) and includes a counter electrode 73 divided into multiple segments (e.g., four segments S1, S2, S3, and S4; see, for example, FIG. 4 ) that are larger than the multiple pixel electrodes 84. The drive substrate 80 has a pair of opposing surfaces (surfaces 80S1 and 80S2) and includes multiple pixel electrodes 84, one for each unit pixel P arranged in an array in the row and column directions. The spatial light modulator 4 further has a first control circuit that individually controls the voltages applied to the multiple pixel electrodes 84 and a second control circuit that individually controls the voltages applied to the counter electrode for each division unit (each of the four segments S1, S2, S3, and S4). In the spatial light modulator 4 of this embodiment, the counter substrate 70 is disposed on the side opposite to the light incident side, and the drive substrate 80 is optically transparent and disposed on the light incident side. The counter electrode 73 is divided into a plurality of segments S1, S2, S3, and S4 and is optically transparent. A light reflecting layer 72 is disposed below the counter electrode 73, specifically, on the side of the counter electrode 73 opposite to the liquid crystal layer 30 side.

[0113] Here, the drive substrate 80 corresponds to a specific example of a "first substrate" as an embodiment of the present disclosure, and the plurality of pixel electrodes 84 correspond to a specific example of a "plurality of first electrodes" as an embodiment of the present disclosure. The counter substrate 70 corresponds to a specific example of a "second substrate" as an embodiment of the present disclosure, and the counter electrode 73 corresponds to a specific example of a "second electrode" as an embodiment of the present disclosure. The liquid crystal layer 30 corresponds to a specific example of a "liquid crystal layer" as an embodiment of the present disclosure.

[0114] The counter substrate 70 includes, for example, a support substrate 71 made of silicon (Si), a light-reflecting layer 72, a counter electrode 73, a planarizing layer 74, and an alignment film 75. The light-reflecting layer 72 includes, for example, a reflective film 72A and a dielectric multilayer film 72B. The reflective film 72A, the dielectric multilayer film 72B, the counter electrode 73, the planarizing layer 74, and the alignment film 75 are provided in this order on the surface of the support substrate 71 facing the liquid crystal layer 30.

[0115] The reflective film 72A reflects the light that has passed through the counter electrode 73 toward the drive substrate 80. The reflective film 72A is formed using a metal material that has light reflectivity, such as aluminum (Al), titanium (Ti), copper (Cu), silicon (Si), silver (Ag), or an alloy thereof (for example, an Al-Cu alloy or an Al-Si alloy).

[0116] Similar to the reflective film 72A, the dielectric multilayer film 72B reflects light transmitted through the counter electrode 73 toward the drive substrate 80. The dielectric multilayer film 72B has a configuration in which at least two types of films each of silicon (Si), hafnium (Hf), tantalum (Ta), niobium (Nb), and titanium (Ti) are alternately stacked, for example.

[0117] In addition, if sufficient reflective performance can be obtained with only the dielectric multilayer film 72B, the reflective film 72A may be omitted from the light reflective layer 72. In other words, the light reflective layer 72 may be made of a dielectric multilayer film.

[0118] As described above, the counter electrode 73 is divided into a plurality of segments (for example, four segments S1, S2, S3, and S4) that are larger than the plurality of pixel electrodes 84. In this embodiment, each division of the counter electrode 73 is referred to as a segment. As in the first embodiment, the counter electrode 73 generates an electric field E in the liquid crystal layer 30 based on a voltage applied to each of the counter electrodes 73 from the AC power supply 40. The voltage applied to the counter electrode 73 is controlled individually for each segment by a second control circuit.

[0119] The counter electrode 73 is made of, for example, a transparent conductive film, and transmits incident light L. The counter electrode 73 is made of, for example, indium tin oxide (ITO).

[0120] The planarization layer 74 is intended to planarize a surface 70S1 of the counter substrate 70 that faces the liquid crystal layer 30. The planarization layer 74 is made of, for example, silicon oxide (SiO ２ ), silicon nitride (Si ３ N ４ ), silicon oxynitride (SiON), SiCN, or the like.

[0121] The alignment film 75 controls the alignment of the liquid crystal molecules 831 contained in the liquid crystal layer 30, and has an alignment control force that aligns the liquid crystal molecules 831 in accordance with the anisotropy of the molecules of the constituent material. Examples of the material of the alignment film 75 include silicon oxide (SiO ２ ), diamond-like carbon or aluminum oxide (Al ２ O ３ The alignment film 75 can be formed by using, for example, a vapor deposition method.

[0122] The drive substrate 80 has, for example, a light-transmitting support substrate 81, a wiring layer 82, a lens layer 83, a plurality of pixel electrodes 84, a planarization layer 85, and an alignment film 86. The wiring layer 82, the lens layer 83, the plurality of pixel electrodes 84, the planarization layer 85, and the alignment film 86 are provided in this order on the surface of the support substrate 81 facing the liquid crystal layer 30. The drive substrate 80 may be formed using a high-temperature polysilicon substrate.

[0123] The wiring layer 82 is provided on the support substrate 81 and includes, for example, a pixel circuit 820 made up of a plurality of transistors that drives the liquid crystal layer 30 for each unit pixel P, a first control circuit, a second control circuit, and the like.

[0124] The lens layer 83 guides light incident on the drive substrate 80 to the plurality of pixel electrodes 84. In the lens layer 83, for example, a plurality of microlenses 83A and 83B are arranged at positions facing the plurality of pixel electrodes 84, respectively.

[0125] As described above, the plurality of pixel electrodes 84 are provided for each unit pixel P. As in the first embodiment, the plurality of pixel electrodes 84 generate an electric field E in the liquid crystal layer 30 based on a voltage applied to each of them from the AC power supply 40. The voltages applied to the plurality of pixel electrodes 84 are individually controlled by the first control circuit.

[0126] The pixel electrodes 84 are made of, for example, a transparent conductive film, such as ITO.

[0127] The planarization layer 85 is intended to planarize a surface 80S1 of the drive substrate 80 that faces the liquid crystal layer 30. The planarization layer 85 is made of, for example, SiO ２ , Si ３ N ４ , SiON, SiCN or the like.

[0128] The alignment film 86 controls the alignment of the liquid crystal molecules 831 contained in the liquid crystal layer 30. The alignment film 86 has an alignment regulating force that aligns the liquid crystal molecules 831 in accordance with the anisotropy of the molecules of the constituent material. By making the directions of the alignment regulating forces of the alignment film 86 and an alignment film 75 (described later) different from each other, it is also possible to generate a twist in the alignment of the plurality of liquid crystal molecules 831 in the liquid crystal layer 30.

[0129] The material of the alignment film 86 is, for example, SiO ２ , diamond-like carbon or Al ２ O ３ The alignment film 86 can be formed by using, for example, a vapor deposition method.

[0130] The liquid crystal layer 30 is composed of liquid crystals driven in, for example, VA mode, TN mode, ECB mode, FFS mode, or IPS mode. The liquid crystal layer 30 is sealed by, for example, a thermosetting or UV-curing sealant commercially available for liquid crystal displays, which bonds the drive substrate 80 and the counter substrate 70 together. After bonding the counter substrate 70 and the drive substrate 80 together with the sealant, liquid crystal is injected and sealed with, for example, a UV-curing sealant. Alternatively, the liquid crystal layer 30 may be fabricated using, for example, an ODF process. A video voltage is supplied to the liquid crystal layer 30 by a plurality of pixel electrodes 84A and a counter electrode 73.

[0131] 22, a partition wall 31 may be provided between the counter substrate 70 and the drive substrate 80, as in the first embodiment. This can shield the fringe electric field Ef generated between the counter electrode 22 divided into a plurality of segments adjacent in the XY plane direction, thereby suppressing unnecessary rotation of the liquid crystal molecules 131.

[0132] [Actions and Effects] The spatial light modulators 1, 1A to 1D, 3A, and 3B described in the first embodiment and modifications 1 to 6 can be used for laser processing, etc., but in that case, high-power light is incident on the spatial light modulators 1, 1A to 1D, 3A, and 3B, which can cause problems such as heat generation. One possible method for solving this problem is to improve the reflectance to suppress heat generation. In order to improve the reflectance, it is desirable to use a dielectric multilayer film, but if a dielectric multilayer film is provided on the pixel electrodes, problems arise such as a decrease in applied voltage and the spread of the electric field within the dielectric multilayer film.

[0133] In contrast, in the spatial light modulator 4 of the present embodiment, the counter substrate 70 is disposed on the side opposite to the light incident side, and the drive substrate 80 is disposed on the light incident side, and a light reflecting layer 72 including a dielectric multilayer film 72B is provided on the counter electrode 73, which is provided on the counter substrate 70 and divided into a plurality of segments S1, S2, S3, and S4, on the side opposite to the liquid crystal layer 30. This solves problems such as a decrease in applied voltage when a dielectric multilayer film is disposed on a pixel electrode and the spread of an electric field within the dielectric multilayer film.

[0134] As described above, in this embodiment, it is possible to provide a spatial light modulator 4 that is highly reliable and compatible with high-definition and high-power light.

[0135] 23 is a schematic diagram illustrating an example of a cross-sectional configuration of a spatial light modulator (spatial light modulator 5) according to a third embodiment of the present disclosure. The spatial light modulator 5 has a liquid crystal layer 30 between a drive substrate 10 and a counter substrate 90 that are disposed opposite each other, and is, for example, a reflective SLM in which light (incident light L) incident from the counter substrate 90 side is reflected by the drive substrate 10 and emitted from the counter substrate 90.

[0136] The spatial light modulator 5 has a liquid crystal layer 30 between a drive substrate 10 and a counter substrate 90, which are arranged opposite each other. The drive substrate 10 has a pair of opposing surfaces (surfaces 10S1 and 10S2) and includes, for example, a plurality of pixel electrodes 13, one for each unit pixel P arranged in an array in the row and column directions. The counter substrate 90 has a pair of opposing surfaces (surfaces 20S1 and 20S2) and includes a counter electrode 92 divided into multiple segments (e.g., five segments S1, S2, S3, S4, and S5) in accordance with variations in the gap between the drive substrate 10 and the counter substrate 90, as in the second modification (see FIG. 15 ). The drive substrate 10 has, for example, a warp in the XY plane. In the spatial light modulator 5 of this embodiment, as shown in FIG. 23 , the counter electrode 92 has a film thickness distribution such that the distance between the drive substrate 10 and the counter substrate 90 is equidistant in the in-plane direction for each of the multiple segments.

[0137] [Configuration of Counter Substrate] The counter substrate 90 has, for example, a light-transmitting support substrate 91, a counter electrode 92, a planarization layer 93, an alignment film 94, and a polarizer 95. The counter electrode 92, the planarization layer 93, and the alignment film 94 are provided in this order on the surface of the support substrate 91 facing the liquid crystal layer 30.

[0138] 15, the counter electrode 92 is divided into, for example, five segments S1, S2, S3, S4, and S5, each larger than the plurality of pixel electrodes 13, in accordance with variations in the gap between the drive substrate 10 and the counter substrate 90. As in the first embodiment, the counter electrode 92 generates an electric field E in the liquid crystal layer 30 based on a voltage applied thereto from the AC power supply 40, and the voltage applied to the counter electrode 92 is controlled individually for each segment by a second control circuit.

[0139] The counter electrode 92 of this embodiment has a film thickness distribution such that the distance between the drive substrate 10 and the counter substrate 90 is equal in the in-plane direction for each of the five segments S1, S2, S3, S4, and S5 shown in FIG. 15 . As an example, when the surface 10S1 of the drive substrate 10 is concavely curved as shown in FIG. 23 , the thickness of the counter electrode 22 is made the thickest in the center of the pixel array unit 100A (e.g., segment S1 shown in FIG. 15 ), where the distance between the surface 10S1 of the drive substrate 10 and the surface 90S1 of the counter substrate 90, which face each other with the liquid crystal layer 30 interposed therebetween, is the largest, and the thickness of the counter electrode 22 is made the thinnest in the four corners of the pixel array unit 100A (e.g., segment S5 shown in FIG. 15 ), where the distance between the surface 10S1 of the drive substrate 10 and the surface 90S1 of the counter substrate 90, which face each other with the liquid crystal layer 30 interposed therebetween, is the smallest. This allows the thickness of the liquid crystal layer 30 in the XY in-plane direction to be made nearly uniform.

[0140] The counter electrode 92 is made of, for example, a transparent conductive film, and transmits incident light L and light reflected by the plurality of pixel electrodes 13. Examples of materials for the counter electrode 92 include ITO, IZO, ZnO, and IGZO. Alternatively, the counter electrode 92 may be formed using a high-temperature polysilicon substrate. This allows the counter electrode 92 to be divided into any size and shape on a two-dimensional plane.

[0141] The planarizing layer 93 is intended to planarize the surface 20S1 of the counter substrate 90 that faces the liquid crystal layer 30. The planarizing layer 93 is made of, for example, SiO ２ , Si ３ N ４ , SiON, SiCN or the like.

[0142] The alignment film 94, like the alignment film 15, controls the alignment of the liquid crystal molecules 131 contained in the liquid crystal layer 30, and has an alignment control force that aligns the liquid crystal molecules 131 according to the anisotropy of the molecules of the constituent material. Examples of materials for the alignment film 94 include silicon oxide (SiO ２ ), diamond-like carbon or aluminum oxide (Al ２ O ３ The alignment film 94 can be formed by using, for example, a vapor deposition method.

[0143] 23 , a partition wall 31 may be provided between the drive substrate 10 and the counter substrate 90, as in the first embodiment. This can shield the fringe electric field Ef generated between the counter electrodes 22 divided into a plurality of segments adjacent in the XY plane direction, thereby suppressing unnecessary rotation of the liquid crystal molecules 131.

[0144] [Functions and Effects] In the spatial light modulator 5 of this embodiment, the opposing electrode 92 has a film thickness distribution for each of a plurality of segments so that the distance between the drive substrate 10 and the opposing substrate 90 is equidistant in the in-plane direction. This reduces the voltage correction width required to correct light modulation characteristics caused by in-plane nonuniformities such as uneven thickness of the liquid crystal layer 30. Furthermore, since it becomes possible to use small transistors with low voltage resistance for the pixel transistors 122 that control the voltage of each of the plurality of pixel electrodes 13, it becomes possible to reduce the unit pixel P and the pixel pitch Pi.

[0145] As described above, in this embodiment, it is possible to provide a spatial light modulator 5 that is high-definition and capable of appropriately correcting light modulation characteristics caused by in-plane non-uniformity of the liquid crystal layer.

[0146] 5. Application Examples Application Example 1 A spatial light modulator (e.g., spatial light modulator 1) according to the present disclosure can be applied to, for example, a holographic display. Fig. 24A shows a direct-view display 1001 to which a spatial light modulator (e.g., spatial light modulator 1) according to the present disclosure is applied. Display 1001 displays digital data of interference fringes using spatial light modulator 1, and can reproduce a three-dimensional image IMG by illuminating the digital data.

[0147] The spatial light modulator 1 according to the present disclosure can accurately correct the light modulation characteristics caused by the in-plane non-uniformity of the liquid crystal layer 30, and therefore can reproduce high-resolution stereoscopic images.

[0148] FIG. 24B shows head-mounted display (HMD) type displays 1002a and 1002b to which a spatial light modulator (e.g., spatial light modulator 1) according to the present disclosure is applied. The displays 1002a and 1002b each include a spatial light modulator 1. The displays 1002a and 1002b are disposed near the left and right eyes of a viewer, respectively. The two spatial light modulators 1 in the displays 1002a and 1002b generate images for the right and left eyes. The viewer can view a stereoscopic image IMG due to the parallax between the images for the right and left eyes. The two spatial light modulators 1 can display images in which the light modulation characteristics resulting from in-plane nonuniformity of the liquid crystal layer 30 have been accurately corrected, allowing the viewer to view a high-resolution, natural stereoscopic image IMG. The displays 1002a and 1002b in FIG. 24B can realize HMDs for AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), and XR (Extended Reality).

[0149] 24C shows a head-up display (HUD) type display 1003 to which a spatial light modulator (e.g., spatial light modulator 1) according to the present disclosure is applied. FIG. 24C shows an in-vehicle display 1003 as an example of an HUD. The spatial light modulator 1 in the display 1003 projects a stereoscopic image IMG onto a car window or the like via a mirror, for example. This allows the display 1003 to display the stereoscopic image IMG so that it is superimposed on people, cars, or buildings in the outside world.

[0150] The spatial light modulator 1 according to the present disclosure can accurately correct the light modulation characteristics resulting from the in-plane non-uniformity of the liquid crystal layer 30, thereby enabling the displays 1002a, 1002b, and 1003 shown in Figures 24B and 24C to be miniaturized and achieving high resolution for the three-dimensional image IMG.

[0151] (Application Example 2) A spatial light modulator (e.g., spatial light modulator 1) according to the present disclosure can be applied to, for example, a laser device. FIG. 25A illustrates an example of the configuration of a laser device to which the spatial light modulator 1 according to the present disclosure is applied. The laser device 1004a illustrated in FIG. 25A is a laser marker device that prints characters and the like using laser light. The laser device 1004a causes light emitted by a laser source 1005 to enter the spatial light modulator 1, and performs printing using the laser light modulated by the spatial light modulator 1 and emitted. The laser device 1004a can split the laser light into multiple beams using the spatial light modulator 1, thereby enabling multiple laser beams to be emitted in parallel, thereby improving throughput. The laser device 1004a can print characters and can also print QR codes (registered trademark) and the like all at once.

[0152] The spatial light modulator 1 according to the present disclosure can accurately correct the light modulation characteristics resulting from the in-plane non-uniformity of the liquid crystal layer 30, thereby reducing the beam diameter of the laser light emitted from the laser device 1004a and improving the printing accuracy of characters, etc.

[0153] 25B shows another example of the configuration of a laser device to which the spatial light modulator (e.g., spatial light modulator 1) of the present disclosure is applied. The laser device 1004B shown in FIG. 25B is a laser soldering device. The laser device 1004B performs soldering using the heat of the laser light output from the spatial light modulator 1. The laser device 1004B can modulate the light intensity distribution in accordance with the land shape LP using the spatial light modulator 1, thereby achieving high-quality soldering with low power consumption.

[0154] 25C shows an example of a land shape LP. The laser device 1004B can modulate the light intensity distribution of the laser light emitted from the laser device 1004B in accordance with various land shapes such as land shapes LP1, LP2, and LP3, each of which has a different size and shape, as shown in FIG.

[0155] The spatial light modulator of the present disclosure (e.g., spatial light modulator 1) can accurately correct the light modulation characteristics resulting from in-plane non-uniformity of the liquid crystal layer 30, and therefore can irradiate the laser light emitted from the laser device 1004b onto lands of various sizes and shapes, enabling high-quality soldering.

[0156] (Application Example 3) The spatial light modulator (e.g., spatial light modulator 1) and display device 2 of the present disclosure can be used for various applications. Figures 26A and 26B show an example of the internal configuration of vehicle 1100, which is an application example of display device 2 equipped with a spatial light modulator (e.g., spatial light modulator 1) of the present disclosure. Figure 26A shows the interior of vehicle 1100 from the rear to the front of vehicle 1100, and Figure 26B shows the interior of vehicle 1100 from diagonally rear to diagonally front of vehicle 1100.

[0157] The vehicle 1100 of Figures 26A and 26B has a center display 1101, a console display 1102, a head-up display 1103, a digital rearview mirror 1104, a steering wheel display 1105, and a rear entertainment display 1106.

[0158] The center display 1101 is disposed on the dashboard 1107 in a position facing the driver's seat 1108 and the passenger's seat 1109. While FIGS. 26A and 26B show an example of a horizontally elongated center display 1101 extending from the driver's seat 1108 side to the passenger's seat 1109 side, the screen size and location of the center display 1101 are arbitrary. The center display 1101 can display information detected by various sensors. As a specific example, the center display 1101 can display an image captured by an image sensor, a distance image to obstacles in front of or to the side of the vehicle measured by a ToF sensor, and the body temperature of a passenger detected by an infrared sensor. The center display 1101 can be used to display, for example, at least one of safety-related information, operation-related information, a life log, health-related information, authentication / identification-related information, and entertainment-related information.

[0159] The safety-related information includes information such as detection of drowsiness, distraction, child mischief, whether a seatbelt is fastened, and whether a passenger has been abandoned. For example, this information is detected by a sensor placed on the back side of the center display 1101. The operation-related information is obtained by detecting gestures related to passenger operations using a sensor. The detected gestures may include operations of various equipment within the vehicle 1100. For example, operations of the air conditioning system, navigation system, AV system, lighting system, etc. are detected. The life log includes life logs of all passengers. For example, the life log includes a record of each passenger's actions while on board. By acquiring and saving the life log, the condition of the passenger at the time of the accident can be confirmed. The health-related information is obtained by detecting the passenger's body temperature using a temperature sensor and inferring the passenger's health condition based on the detected body temperature. Alternatively, an image sensor may be used to capture an image of the passenger's face and infer the passenger's health condition from the facial expression captured in the image. Furthermore, the system may have an automated voice conversation with the occupant and estimate the occupant's health condition based on the occupant's responses. The authentication / identification-related information includes a keyless entry function that uses a sensor to perform facial authentication, a function that automatically adjusts seat height and position using facial recognition, etc. The entertainment-related information includes a function that uses a sensor to detect operation information of an AV device by the occupant, a function that recognizes the occupant's face using a sensor and provides content suitable for the occupant via the AV device, etc.

[0160] The console display 1102 can be used to display, for example, life log information. The console display 1102 is disposed near the shift lever 1111 on the center console 1110 between the driver's seat 1108 and the passenger seat 1109. Information detected by various sensors can also be displayed on the console display 1102. Furthermore, the console display 1102 may display an image of the vehicle's surroundings captured by an image sensor, or may display an image showing the distance to an obstacle around the vehicle.

[0161] The head-up display 1103 is virtually displayed behind the windshield 1112 in front of the driver's seat 1108. The head-up display 1103 can be used to display, for example, at least one of safety-related information, operation-related information, a life log, health-related information, authentication / identification-related information, and entertainment-related information. Because the head-up display 1103 is often virtually located in front of the driver's seat 1108, it is suitable for displaying information directly related to the operation of the vehicle 1100, such as the speed of the vehicle 1100 and the remaining fuel (battery) level.

[0162] The digital rearview mirror 1104 can not only display the rear of the vehicle 1100, but also the status of passengers in the rear seats. Therefore, by placing a sensor on the back side of the digital rearview mirror 1104, it can be used to display life log information, for example.

[0163] The steering wheel display 1105 is disposed near the center of the steering wheel 1113 of the vehicle 1100. The steering wheel display 1105 can be used to display, for example, at least one of safety-related information, operation-related information, a life log, health-related information, authentication / identification-related information, and entertainment-related information. In particular, because the steering wheel display 1105 is located near the driver's hands, it is suitable for displaying life log information such as the driver's body temperature, and for displaying information related to the operation of AV equipment, air conditioning equipment, etc.

[0164] The rear entertainment display 1106 is attached to the back side of the driver's seat 108 and the passenger seat 1109 and is intended for viewing by rear seat passengers. The rear entertainment display 1106 can be used to display, for example, at least one of safety-related information, operation-related information, a life log, health-related information, authentication / identification-related information, and entertainment-related information. In particular, since the rear entertainment display 1106 is located directly in front of the rear seat passengers, information related to the rear seat passengers is displayed on the rear entertainment display 1106. For example, the rear entertainment display 1106 may display information related to the operation of an AV device or an air conditioning system, or may display the results of measurements of the body temperature of the rear seat passengers using a temperature sensor.

[0165] As described above, by arranging a sensor on the back side of the spatial light modulator 1, the distance to a surrounding object can be measured. Optical distance measurement methods can be broadly divided into passive and active types. Passive methods measure distance by receiving light from an object without projecting light from the sensor onto the object. Passive methods include the lens focusing method, the stereo method, and the monocular vision method. Active methods measure distance by projecting light onto an object and receiving the light reflected from the object with a sensor. Active methods include the optical radar method, the active stereo method, the photometric stereo method, the moire topography method, and the interferometry method. The spatial light modulator 1 according to the present disclosure can be applied to any of these distance measurement methods. By using a sensor arranged on the back side of the spatial light modulator 1 according to the present disclosure, the above-mentioned passive or active distance measurements can be performed.

[0166] Application Example 4 The spatial light modulator of the present disclosure (for example, the spatial light modulator 1) is applicable not only to various displays used in vehicles, but also to displays mounted on various display devices 2.

[0167] Fig. 27A is a front view of a digital camera 1120 which is an application example of the display device 2, and Fig. 27B is a rear view of the digital camera 1120. The digital camera 1120 in Fig. 27A and Fig. 27B shows an example of a single-lens reflex camera in which the lens 1121 is replaceable, but the present invention is also applicable to cameras in which the lens 1121 is not replaceable.

[0168] 27A and 27B, when the photographer holds the grip 123 of the camera body 1122, looks through the electronic viewfinder 1124, decides on the composition of the shot, adjusts the focus, and presses the shutter 1125, the photographed data is saved in the camera's internal memory. As shown in Fig. 27B, the rear side of the camera is provided with a monitor screen 1126 that displays photographed data, live images, etc., and the electronic viewfinder 1124. In addition, a sub-screen that displays setting information such as shutter speed and exposure value may be provided on the top surface of the camera.

[0169] By arranging the sensor on the back side of a monitor screen 1126, an electronic viewfinder 1124, a sub-screen, etc. used in a camera, it can be used as the spatial light modulator 1 according to the present disclosure.

[0170] (Application Example 5) The spatial light modulator (e.g., the spatial light modulator 1) of the present disclosure can also be applied to a head-mounted display (hereinafter referred to as an HMD). The HMD can be used for virtual reality (VR), augmented reality (AR), mixed reality (MR), substitutional reality (SR), or the like.

[0171] Fig. 28A is an external view of an HMD 1130, which is an application example of the display device 2. The HMD 1130 in Fig. 28A has a mounting member 1131 for being worn over a person's eyes. This mounting member 1131 is secured by hooking it onto a person's ear, for example. A spatial light modulator 1132 is provided inside the HMD 1130, and a person wearing the HMD 1130 can view a 3D image or the like using this spatial light modulator 1132. The HMD 1130 is equipped with, for example, a wireless communication function and an acceleration sensor, and can switch the 3D image or the like displayed on the spatial light modulator 1132 depending on the posture, gestures, etc. of the wearer.

[0172] Alternatively, a camera may be provided in the HMD 1130 to capture an image of the wearer's surroundings, and an image obtained by combining the image captured by the camera with an image generated by a computer may be displayed on the spatial light modulator 1132. For example, a camera may be placed on the back side of the spatial light modulator 1132, which is viewed by the wearer of the HMD 1130, to capture an image of the area around the wearer's eyes, and the captured image may be displayed on another display provided on the outer surface of the HMD 1130, allowing people around the wearer to grasp the wearer's facial expressions and eye movements in real time.

[0173] Various types of HMDs 1130 are possible. For example, as shown in FIG. 28B , the spatial light modulator 1 according to the present disclosure can also be applied to smart glasses 1130A that display various information on glasses 1137. The smart glasses 1130A in FIG. 28B include a main body 1134, an arm 1135, and a lens barrel 1136. The main body 1134 is connected to the arm 1135. The main body 1134 is detachable from the glasses 1137. The main body 1134 incorporates a control board and a display unit for controlling the operation of the smart glasses 1130A. The main body 1134 and the lens barrel 1136 are connected to each other via the arm 1135. The lens barrel 1136 emits image light emitted from the main body 1134 via the arm 1135 toward the lenses 1138 of the glasses 1137. This image light enters the human eye through the lens 1138. A person wearing the smart glasses 1130A in FIG. 28B can see not only the surrounding situation but also various information emitted from the lens barrel 1136, just like with regular glasses.

[0174] (Application Example 6) The spatial light modulator (e.g., spatial light modulator 1) of the present disclosure can also be applied to a television device (hereinafter referred to as a TV). Recent TVs tend to have as small a frame as possible from the viewpoints of miniaturization and aesthetic design. For this reason, when a camera for photographing viewers is installed in a TV, it is desirable to place the camera on the back side of the TV's display panel.

[0175] Fig. 29 is an external view of a TV 140, which is an application example of the display device 2. The TV 1140 in Fig. 29 has an extremely small frame, and almost the entire front side is the display area. The TV 1140 may have a built-in sensor such as a camera for capturing images of viewers.

[0176] (Application Example 7) The spatial light modulator (e.g., spatial light modulator 1) of the present disclosure can also be applied to smartphones and mobile phones. FIG. 30 is an external view of a smartphone 1150, which is an application example of the display device 2. In the example of FIG. 30 , the display surface 1152 extends to nearly the outer size of the display device 2, and the width of the bezel 1151 around the display surface 1152 is set to a few millimeters or less. Typically, a front camera is mounted on the bezel 1151, but in FIG. 30 , an image sensor module functioning as a front camera is disposed on the back side of the display surface 1152, for example, approximately in the center. By providing the front camera on the back side of the display surface 1152 in this way, there is no need to place the front camera in the bezel 1151, and the width of the bezel 1151 can be narrowed.

[0177] Although the present disclosure has been described above with reference to the first to third embodiments, modifications 1 to 6, and application examples, the present disclosure is not limited to the above-described embodiments, etc., and various modifications are possible. For example, the spatial light modulator of the present disclosure (e.g., spatial light modulator 1) is not limited to the configurations described in the above-described embodiments, etc.

[0178] For example, in the above-described embodiment and the like, an example has been shown in which a plurality of pixel electrodes 13A are provided for each unit pixel P, but this is not limiting. For example, the plurality of pixel electrodes 13A may be arranged in parallel for each unit pixel P in the X-axis direction, and may extend across the plurality of unit pixels P in the Y-axis direction.

[0179] Furthermore, for example, the drive substrate 10 and the counter substrate 20 may further be provided with a polarizing plate.

[0180] The effects described in this specification are merely examples and are not limited to those described, and other effects may also be obtained.

[0181] The present technology can also be configured as follows. According to the present technology configured as follows, it is possible to provide a spatial light modulator and a display device having high definition and excellent light modulation characteristics. (1) A spatial light modulator comprising: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction intersecting each other; a second substrate arranged opposite the first substrate and having a second electrode divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls voltages applied to the plurality of first electrodes; a second control circuit that individually controls voltages applied to the second electrodes for each division unit; and partition walls provided between the first substrate and the second substrate and in at least a portion between the plurality of segments adjacent in a plan view. (2) The spatial light modulator according to (1), wherein the partition walls are formed to include a dielectric material. (3) The spatial light modulator according to (1) or (2), wherein the liquid crystal layer contains a plurality of liquid crystal molecules, and the partition walls are arranged in a direction parallel to the alignment direction of the plurality of liquid crystal molecules. (4) The spatial light modulator according to any one of (1) to (3), wherein the partition walls penetrate the liquid crystal layer. (5) The spatial light modulator according to any one of (1) to (4), wherein the partition walls extend from the second substrate toward the first substrate and have an end face facing the first substrate within the liquid crystal layer. (6) The spatial light modulator according to any one of (1) to (5), wherein the partition walls extend from the first substrate toward the second substrate and have an end face facing the second substrate within the liquid crystal layer. (7) The spatial light modulator according to any one of (1) to (6), wherein the first substrate is optically transparent, the second substrate further has a light-reflecting layer stacked in this order together with the second electrode having light transparency on the side of the second electrode opposite to the liquid crystal layer side, and light transmitted through the first substrate is reflected by the light-reflecting layer and then transmitted through the first substrate to be output. (8) The spatial light modulator according to (7), wherein the first substrate further has a plurality of microlenses respectively provided on the side of the plurality of first electrodes opposite to the liquid crystal layer side.(9) The spatial light modulator according to any one of (1) to (8), wherein a voltage correction width of the voltage applied to the second electrode controlled by the second control circuit is larger than a voltage correction width of the voltage applied to the plurality of first electrodes controlled by the first control circuit. (10) The spatial light modulator according to any one of (1) to (9), wherein the first control circuit performs fine adjustment of the light modulation characteristics of the liquid crystal layer, and the second control circuit performs coarse adjustment of the light modulation characteristics of the liquid crystal layer. (11) The spatial light modulator according to (10), wherein the first control circuit individually adjusts the voltages applied to the plurality of first electrodes based on voltage control by the second control circuit in division units of the second electrodes. (12) The spatial light modulator according to any one of (1) to (11), wherein the second electrode is divided along the boundaries of the plurality of first electrodes. (13) The spatial light modulator according to any one of (1) to (12), wherein the second electrode is divided regardless of boundaries between the plurality of first electrodes. (14) The spatial light modulator according to any one of (1) to (13), wherein the first substrate has a warp on a first surface facing the liquid crystal layer, and the second electrode is divided into a plurality of segments in accordance with the warp of the first surface. (15) The spatial light modulator according to any one of (9) to (14), wherein the second electrode has a film thickness distribution such that the distance between the first substrate and the second substrate is equidistant in the in-plane direction for each of the plurality of segments. (16) The spatial light modulator according to any one of (1) to (15), wherein the second electrode is divided randomly. (17) The spatial light modulator according to any one of (1) to (16), wherein the second electrode is divided along a non-periodic pattern shape. (18) The spatial light modulator according to any one of (1) to (17), further comprising a reflective layer disposed on a pair of surfaces of the liquid crystal layer facing the first substrate and the second substrate, respectively, and configured to resonate light of a predetermined frequency to increase a phase difference modulation amount.(19) The spatial light modulator according to any one of (1) to (18), further comprising a microstructure disposed on at least one of a pair of surfaces of the liquid crystal layer facing the first substrate and the second substrate, the microstructure resonating light of a predetermined frequency to increase a phase difference modulation amount. (20) A display device including a spatial light modulator having: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction that intersect with each other; a second substrate disposed opposite the first substrate and having a second electrode divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls a voltage applied to the plurality of first electrodes; a second control circuit that individually controls a voltage applied to the second electrode for each division unit; and partition walls provided between the first substrate and the second substrate and at least partially between the plurality of segments adjacent to each other in a plan view. (21) A spatial light modulator comprising: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction that intersect each other; a second substrate arranged opposite the first substrate and having second electrodes divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls voltages applied to the plurality of first electrodes; and a second control circuit that individually controls voltages applied to the second electrodes for each division unit, wherein the first substrate has a warp on a first surface facing the liquid crystal layer, and the second electrodes have a film thickness distribution such that the distance between the first substrate and the second substrate is equidistant in the in-plane direction for each of the plurality of segments.(22) A spatial light modulator comprising: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction that intersect with each other; a second substrate arranged opposite the first substrate and having second electrodes divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls voltages applied to the plurality of first electrodes; and a second control circuit that individually controls voltages applied to the second electrodes for each division unit, wherein the first substrate is optically transparent; and the second substrate has a dielectric multilayer film and a light reflecting layer laminated in this order on the side of the optically transparent second electrodes opposite the liquid crystal layer side.

[0182] This application claims priority based on Japanese Patent Application No. 2023-214885, filed on December 20, 2023, in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0183] 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 spatial light modulator comprising: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction that intersect with each other; a second substrate arranged opposite the first substrate and having a second electrode divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls a voltage applied to the plurality of first electrodes; a second control circuit that individually controls a voltage applied to the second electrodes for each division unit; and a partition provided between the first substrate and the second substrate and at least partially between the plurality of segments that are adjacent in a planar view.

2. The spatial light modulator according to claim 1, wherein said partition is formed of a dielectric material.

3. The spatial light modulator according to claim 1, wherein the liquid crystal layer contains a plurality of liquid crystal molecules, and the partition walls are provided in a direction parallel to the alignment direction of the plurality of liquid crystal molecules.

4. The spatial light modulator according to claim 1, wherein said partitions penetrate said liquid crystal layer.

5. The spatial light modulator according to claim 1, wherein said partition extends from said second substrate toward said first substrate and has an end surface facing said first substrate within said liquid crystal layer.

6. The spatial light modulator according to claim 1, wherein said partition extends from said first substrate toward said second substrate and has an end surface facing said second substrate within said liquid crystal layer.

7. A spatial light modulator as described in claim 1, wherein the first substrate is optically transparent, the second substrate further has a light-reflecting layer laminated in sequence with the second electrode, the second electrode being optically transparent, on the side of the second electrode opposite the liquid crystal layer, and light transmitted through the first substrate is reflected by the light-reflecting layer and then transmitted through the first substrate to be output.

8. The spatial light modulator according to claim 7, wherein said first substrate further comprises a plurality of microlenses provided on the opposite side of said plurality of first electrodes from said liquid crystal layer side.

9. A spatial light modulator as described in claim 1, wherein a voltage compensation range of the voltage applied to the second electrodes controlled by the second control circuit is larger than a voltage compensation range of the voltage applied to the plurality of first electrodes controlled by the first control circuit.

10. The spatial light modulator of claim 1, wherein said first control circuit performs fine adjustment of the light modulation characteristics of said liquid crystal layer, and said second control circuit performs coarse adjustment of the light modulation characteristics of said liquid crystal layer.

11. The spatial light modulator of claim 10, wherein the first control circuit individually adjusts the voltages applied to the plurality of first electrodes based on voltage control by the second control circuit in units of divisions of the second electrodes.

12. The spatial light modulator of claim 1, wherein the second electrodes are divided along boundaries of the plurality of first electrodes.

13. The spatial light modulator of claim 1, wherein said second electrodes are divided regardless of boundaries of said plurality of first electrodes.

14. The spatial light modulator of claim 1, wherein the first substrate has a warp on a first surface facing the liquid crystal layer, and the second electrode is divided into a plurality of segments in accordance with the warp of the first surface.

15. A spatial light modulator as described in claim 9, wherein the second electrode has a film thickness distribution such that the distance between the first substrate and the second substrate is equal in the in-plane direction for each of the plurality of segments.

16. The spatial light modulator of claim 1, wherein said second electrode is randomly divided.

17. The spatial light modulator of claim 1, wherein the second electrode is divided along a non-periodic pattern shape.

18. The spatial light modulator of claim 1, further comprising a reflective layer disposed on a pair of surfaces of the liquid crystal layer facing the first substrate and the second substrate, respectively, for resonating light of a predetermined frequency to increase the amount of phase difference modulation.

19. The spatial light modulator of claim 1, further comprising a microstructure disposed on at least one of a pair of surfaces of the liquid crystal layer facing the first substrate and the second substrate, the microstructure resonating with light of a predetermined frequency to increase the amount of phase difference modulation.

20. A display device equipped with a spatial light modulator having: a first substrate having a plurality of first electrodes arranged in a first direction and a second direction intersecting each other; a second substrate arranged opposite the first substrate and having a second electrode divided into a plurality of segments larger than the plurality of first electrodes; a liquid crystal layer provided between the first substrate and the second substrate; a first control circuit that individually controls a voltage applied to the plurality of first electrodes; a second control circuit that individually controls a voltage applied to the second electrodes for each division unit; and a partition provided between the first substrate and the second substrate and at least in a portion between the plurality of segments adjacent to each other in a planar view.

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