Optical phase modulation element and display device

Abstract

This optical phase modulation element (1A) comprises a plurality of divided regions (21, 22), which are provided in mutually different regions in the in-plane direction, and in which liquid crystal materials having mutually different refractive index anisotropy are enclosed, the divided regions (21, 22) displaying phase distribution patterns for color having mutually different wavelengths.

Description

[Technical field]

[0001] The present disclosure relates to an optical phase modulation element using a liquid crystal material, and a display device. [Background technology]

[0002] There is known a display device that displays an image by modulating the luminance (intensity) of light using a light intensity modulation element. There is also known an optical phase modulation element that generates a desired reconstructed image by modulating the phase of light. The light intensity modulation element and the optical phase modulation element are configured, for example, by a liquid crystal panel. As an application example of the optical phase modulation element, there is a technology that generates a reconstructed image that is phase-modulated according to an image to be displayed, and uses the reconstructed image as illumination light for a light intensity modulation element for image display (see Patent Documents 1 to 3). In particular, Patent Document 3 proposes a technology that generates illumination light of the three primary colors required for color display using one optical phase modulation element. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2008-292725 A [Patent Document 2] JP 2008-89686 A [Patent Document 3] Japanese Patent Application Publication No. 4-293075 Summary of the Invention

[0004] When performing phase modulation of multiple color lights using one optical phase modulation element filled with a single liquid crystal material, the phase modulation characteristics and light resistance, etc. vary depending on the wavelength due to the nature of the liquid crystal material, which leads to a decrease in performance and reliability.

[0005] It is desirable to provide an optical phase modulation element and a display device that can achieve high performance and high reliability.

[0006] An optical phase modulation element according to one embodiment of the present disclosure comprises a plurality of divided regions that are arranged in different regions in an in-plane direction, are filled with liquid crystal materials having different refractive index anisotropies, and each of the divided regions displays a phase distribution pattern for a color having a different wavelength.

[0007] A display device according to one embodiment of the present disclosure includes a light source unit that emits a plurality of colored lights having different wavelengths from each other, and an optical phase modulation element that phase-modulates each of the plurality of colored lights from the light source unit, the optical phase modulation element being provided in different regions in an in-plane direction and including a plurality of divided regions in which liquid crystal materials having different refractive index anisotropies are filled, each of which displays a phase distribution pattern for a color having a different wavelength from each other.

[0008] In an optical phase modulation element or display device according to one embodiment of the present disclosure, liquid crystal materials having different refractive index anisotropies are filled in each of a plurality of divided regions, and each of the divided regions displays phase distribution patterns for colors having different wavelengths. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view showing an overview of a luminance modulation type display device. [Diagram 2] FIG. 1 is a cross-sectional view showing an overview of a luminance modulation type display device. [Diagram 3] FIG. 1 is a perspective view showing an overview of a phase modulation type display device. [Figure 4] FIG. 1 is a cross-sectional view showing an overview of a phase modulation type display device. [Diagram 5] FIG. 2 is an explanatory diagram showing an outline of an index ellipsoid. [Figure 6] FIG. 2 is an explanatory diagram showing an example of a macroscopic refractive index distribution of a liquid crystal material. [Figure 7] 1 is a cross-sectional view showing an overview of a VA mode liquid crystal panel. [Figure 8] FIG. 1 is a front view showing an outline of a luminance modulation type liquid crystal panel. [Figure 9] 1 is a cross-sectional view showing an overview of a luminance modulation type liquid crystal panel. [Figure 10] FIG. 1 is a front view showing an overview of a phase modulation type liquid crystal panel. [Figure 11] 1 is a cross-sectional view showing an overview of a phase modulation type liquid crystal panel. [Figure 12] FIG. 1 is an explanatory diagram showing an overview of a single-plate color optical phase modulation element according to a comparative example. [Figure 13] FIG. 1 is an explanatory diagram showing an example of wavelength dispersion characteristics of refractive index anisotropy of a general liquid crystal material. [Figure 14] FIG. 2 is an explanatory diagram showing an example of a relative luminosity curve. [Figure 15] 1 is a plan view that illustrates a first example of an in-plane structure of an optical phase modulation element according to a first embodiment of the present disclosure. [Figure 16] 4 is a plan view illustrating a second example of an in-plane structure of the optical phase modulation element according to the first embodiment. FIG. [Figure 17] FIG. 11 is a plan view illustrating a third example of an in-plane structure of the optical phase modulation element according to the first embodiment. [Figure 18] FIG. 2 is a plan view illustrating a first modified example of the in-plane structure of the optical phase modulation element according to the first embodiment. [Figure 19] FIG. 11 is a plan view illustrating a second modified example of the in-plane structure of the optical phase modulation element according to the first embodiment. [Figure 20] 1 is a configuration diagram illustrating an example of a display device using an optical phase modulation element according to a first embodiment. [Figure 21] 1 is a cross-sectional view illustrating a schematic configuration example of an optical phase modulation element according to a first embodiment. [Figure 22] FIG. 4 is an explanatory diagram showing the type of liquid crystal material used in the optical phase modulation element according to each embodiment. [Figure 23] FIG. 1 is a plan view showing an overview of an optical phase modulation element according to a comparative example. [Figure 24] 1 is an explanatory diagram showing values ​​of cell gap d of optical phase modulation elements according to a comparative example and Example 1, and types and physical properties of liquid crystal materials. FIG. [Diagram 25] 11 is an explanatory diagram showing voltage characteristics of the phase modulation amount of an optical phase modulation element according to a comparative example. FIG. [Figure 26] 4 is an explanatory diagram showing voltage characteristics of the phase modulation amount of the optical phase modulation element according to the first embodiment. FIG. [Figure 27] FIG. 4 is an explanatory diagram showing voltage values ​​required for 2π-modulating the phase in the optical phase modulation elements according to the comparative example and Example 1. [Figure 28] 11 is an explanatory diagram showing the results of a light resistance test on an optical phase modulation element according to a comparative example. FIG. [Figure 29] 4 is an explanatory diagram showing the results of a light resistance test on the optical phase modulation element according to Example 1. FIG. [Diagram 30] 10 is an explanatory diagram showing the results of a reliability test on the optical phase modulation elements according to the comparative example and Example 1. FIG. [Diagram 31] 11 is an explanatory diagram showing values ​​of cell gap d of optical phase modulation elements according to a comparative example and an embodiment 2, and types and physical properties of liquid crystal materials. FIG. [Diagram 32] 11 is an explanatory diagram showing voltage characteristics of the phase modulation amount of an optical phase modulation element according to a comparative example. FIG. [Diagram 33] FIG. 11 is an explanatory diagram showing voltage characteristics of the phase modulation amount of the optical phase modulation element according to the second embodiment. [Diagram 34] FIG. 11 is an explanatory diagram showing voltage values ​​required for 2π-modulating the phase in the optical phase modulation elements according to the comparative example and the second embodiment. [Diagram 35] 11 is an explanatory diagram showing the results of a light resistance test on an optical phase modulation element according to a comparative example. FIG. [Diagram 36] FIG. 11 is an explanatory diagram showing the results of a light resistance test on the optical phase modulation element according to Example 2. [Figure 37] 13 is an explanatory diagram showing values ​​of cell gap d of optical phase modulation elements according to a comparative example and Example 3, and types and physical properties of liquid crystal materials. FIG. [Figure 38] 11 is an explanatory diagram showing voltage characteristics of the phase modulation amount of an optical phase modulation element according to a comparative example. FIG. [Figure 39] FIG. 11 is an explanatory diagram showing voltage characteristics of the phase modulation amount of the optical phase modulation element according to the third embodiment. [Diagram 40]FIG. 11 is an explanatory diagram showing voltage values ​​required for 2π-modulating the phase in the optical phase modulation elements according to the comparative example and the third embodiment. [Diagram 41] FIG. 11 is an explanatory diagram showing the results of a light resistance test on the optical phase modulation element according to Example 3. [Diagram 42] 10 is an explanatory diagram showing evaluation results of reconstructed images in the optical phase modulation elements according to a comparative example, an embodiment 1, and an embodiment 3. FIG. [Diagram 43] 13 is an explanatory diagram showing the type of alignment film, the value of the cell gap d, and the type and physical properties of the liquid crystal material of the optical phase modulation element according to Example 4. FIG. [Diagram 44] FIG. 2 is an explanatory diagram showing wavelength characteristics of light absorptance in a metal. [Diagram 45] 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; [Diagram 46] 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG. [Figure 47] 1 is a configuration diagram showing an example of a schematic configuration of an endoscopic surgery system. [Figure 48] 48 is a block diagram showing an example of the functional configuration of the camera head and the CCU shown in FIG. 47. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be made in the following order. 0. Comparative Example (Figs. 1 to 14) 1. First embodiment 1.1 Overview (Example of planar configuration of optical phase modulation element) (Figs. 15 to 19) 1.2 Example of display device configuration (Figure 20) 1.3 Example of cross-sectional structure of optical phase modulation element (Figure 21) 1.4 Example (Figs. 22 to 43) 1.5 Modifications (Figure 44) 2. Application Examples (Figures 45 to 48) 2.1 First application example 2.2 Second application example 3. Other embodiments

[0011] <0. Comparative Examples> 1 and 2 show an overview of a display device using a luminance modulation method. A typical configuration of a projection display device (projector) is, for example, as shown in Figures 1 and 2, in which uniform illumination light emitted from a light source 500 is irradiated onto a light intensity modulation element 501, and light intensity modulation is performed to generate an image, and the generated image is projected onto a screen 50 through a projection lens.

[0012] As the light intensity modulation element 501, an LCD (Liquid Crystal Display: Liquid Crystal Display Panel) or a DMD (Digital Micro-mirror Device: Mirror Device) is usually used. In particular, a liquid crystal projector using a liquid crystal panel has good color reproducibility and can realize high image quality. In a liquid crystal projector, a liquid crystal panel is used as an optical shutter. FIG. 1 and FIG. 2 show an example in which a transmissive liquid crystal panel is used as the light intensity modulation element 501. The liquid crystal panel is configured by sandwiching a liquid crystal layer 513 containing a plurality of liquid crystal molecules 514 between a pair of substrates 502, 503. When the light intensity modulation element 501 is a transmissive liquid crystal panel, a polarizer 521 is arranged in the incident direction of light, and an analyzer 522 is arranged in the exit direction of light. The polarizer 521 outputs polarized light polarized in a predetermined polarization direction of the incident light L11. In the case of a display device using a luminance modulation method, one pixel of the light intensity modulation element 501 corresponds to one pixel of an image that is finally displayed. When the light intensity modulation element 501 is a liquid crystal panel, when displaying a dark image area, it is necessary to block the illumination light by the liquid crystal panel, and some light is not used for display, resulting in a significant decrease in the light utilization efficiency.

[0013] In response to this, a technology has been disclosed for a phase modulation display device that uses an SLM (Spatial Light Modulator) as a diffraction element to generate illumination light, thereby distributing a portion of the light irradiated on a low-luminance pixel region to a high-luminance region (see, for example, Patent Documents 1 and 2). A liquid crystal panel can also be used as the optical phase modulation element.

[0014] 3 and 4 show an outline of a phase modulation type display device. 3 and 4 show an example in which a reflective diffraction element is used as the optical phase modulation element 1. In a display device using the phase modulation method, for example, a uniform illumination light emitted from a light source 500 is irradiated onto the optical phase modulation element 1 to perform phase modulation, and a reconstructed image generated by this is projected onto a screen 50. A display device using the phase modulation method is highly efficient because it uses light diffraction. In the case of a display device using the phase modulation method, one pixel of the optical phase modulation element 1 does not necessarily correspond to one pixel of the image to be finally displayed, and it is possible to make multiple pixels in the optical phase modulation element 1 correspond to one pixel of the image to be displayed. Since it is possible to configure one pixel of the image to be finally displayed using multiple pixels in the optical phase modulation element 1, it is also characterized in that the pixel display is stable even if a pixel defect occurs in the optical phase modulation element 1. In addition, color display is also possible, and a technology has been disclosed in which illumination light of the three primary colors R (red), G (green), and B (blue) is generated using different optical phase modulation elements 1 for each color.

[0015] The propagation of light in these luminance modulation and phase modulation methods will be described using a liquid crystal panel as an example.

[0016] The liquid crystal material used in the liquid crystal panel is a uniaxial index ellipsoid 530 with one optical axis, as shown in Fig. 5. In Fig. 5, the z-axis is the major axis of index ellipsoid 530, and the x-axis and y-axis are the minor axes of index ellipsoid 530. The optical axis of index ellipsoid 530 indicates the normal direction of a plane when a cut surface passing through the center of the ellipsoid forms a circle, and corresponds to the z-axis in Fig. 5. In Fig. 5, if the refractive index of index ellipsoid 530 in the x-axis direction is nx, the refractive index in the y-axis direction is ny, and the refractive index in the z-axis direction is nz, the relationship of the magnitude of the refractive indices is nx=ny, nx,ny <nzとなる。

[0017] FIG. 6 shows an example of a macroscopic refractive index distribution of a liquid crystal material. The orientation direction of the liquid crystal molecules 514 is represented by a unit vector n called a director. Macroscopically, the average refractive index distribution of the liquid crystal molecules 514 can be regarded as one refractive index ellipsoid 530. As with the refractive index ellipsoid 530, the long axis and the optical axis of the liquid crystal molecules 514 coincide. The liquid crystal material has refractive index anisotropy (= birefringence). The refractive index refers to the rate at which the traveling speed of a light wave traveling through a medium slows down, and birefringence refers to the phenomenon in which two refracted lights appear when light is incident on a substance. The light that vibrates parallel to the optical axis of the liquid crystal molecules 514 is called an extraordinary ray, and the refractive index for the extraordinary ray is expressed as ne. The light that vibrates perpendicular to the long axis of the liquid crystal molecules 514 is called an ordinary ray, and the refractive index for the ordinary ray is expressed as no. The difference between the refractive index ne and the refractive index no is called the refractive index anisotropy Δn (=ne-no). When this refractive index anisotropy exists, a phase difference occurs in the light depending on the incident direction.

[0018] (Example of liquid crystal panel configuration) FIG. 7 shows an overview of a liquid crystal panel in VA (Vertical Alignment) mode.

[0019] In the example shown in FIG. 7, the liquid crystal material sealed in the liquid crystal panel is a negative type liquid crystal, and the orientation is vertical orientation. A VA mode liquid crystal panel is formed by filling a liquid crystal layer 513 between a pair of substrates 502 and 503. A pixel electrode 512 for controlling the orientation of the liquid layer molecules 514 constituting the liquid crystal layer 513 is patterned on the surface of one substrate 502 facing the liquid crystal layer 513. Similarly, a pixel electrode 511 for controlling the orientation of the liquid layer molecules 514 constituting the liquid crystal layer 513 is patterned on the surface of the other substrate 503 facing the liquid crystal layer 513. Although not shown, an orientation film is provided in a state of covering each of the pixel electrodes 511 and 512. FIG. 7(A) shows a state in which no voltage is applied between the pixel electrodes 511 and 512 (voltage OFF), and FIG. 7(B) shows a state in which a voltage is applied between the pixel electrodes 511 and 512 (voltage ON). When no voltage is applied, the liquid crystal molecules 514 stand upright, and when a voltage is applied, the liquid crystal molecules 513 fall down.

[0020] When a voltage is applied to the liquid crystal layer 513 by the pixel electrodes 511 and 512, the orientation is controlled by aligning the tilt direction of the liquid crystal molecules 514 constituting the liquid crystal layer 513 over the entire surfaces of the pair of substrates 502 and 503. For this reason, when no voltage is applied, the liquid crystal molecules 514 are given a uniform pretilt angle. For example, in a VA mode liquid crystal panel, the surface of the alignment film is configured so that the liquid crystal molecules 514 have a pretilt angle (angle with respect to the normal direction to the substrate surface) of 2° to 6° over the entire surface of the display area.

[0021] In a VA mode liquid crystal panel, for example, by arranging two polarizing plates in a crossed Nicol position, a normally black display is achieved in which black is displayed when no voltage is applied and white is displayed when voltage is applied.

[0022] (Optical action of brightness modulation type liquid crystal panel) 8 and 9 show an overview of a luminance modulation type liquid crystal panel as the light intensity modulation element 501. Fig. 8 shows a schematic diagram of the configuration of the light intensity modulation element 501 as viewed from the front direction and the polarization state of light. Fig. 9 shows a schematic diagram of the configuration in a cross section of the light intensity modulation element 501 and the polarization state of light. Figs. 8 and 9 show a configuration example in which the light intensity modulation element 501 is a transmissive VA mode liquid crystal panel.

[0023] A polarizer 521 serving as an incident-side polarizing plate is disposed in the light-intensity modulation element 501 in the incident direction of light, and an analyzer 522 serving as an output-side polarizing plate is disposed in the light-output direction of light. The light-intensity modulation element 501 is configured such that a liquid crystal layer 513 is sandwiched between a plurality of opposing pixel electrodes 511 and a plurality of pixel electrodes 512. The liquid crystal layer 513 has a plurality of liquid crystal molecules 514. The liquid crystal layer 513 is arranged such that the plurality of liquid crystal molecules 514 are aligned in a predetermined direction.

[0024] The polarizer 521 emits polarized light L12 that is polarized in a predetermined polarization direction from the non-polarized incident light L11. For example, as shown in FIG. 8, the alignment direction of the liquid crystal molecules 514 is tilted at 45° with respect to the polarization direction of the polarized light L12 when viewed from the front. As shown in FIG. 9, the tilt in the cross section of the liquid crystal molecules 514 changes according to the voltage applied between the opposing pixel electrodes 511 and 512. As a result, the polarization state of the intensity-modulated light L13 emitted from the light-intensity modulation element 501 changes according to the applied voltage. The amount of light finally emitted from the analyzer 522 changes according to the polarization state of the intensity-modulated light L13.

[0025] In the luminance modulation method, the polarization of light is used to express gradation characteristics. The luminance of each pixel changes as the polarization state of the intensity-modulated light L13 emitted from the light-intensity modulation element 501 changes. Figure 9 shows how the incident linearly polarized polarized light L12 changes when the liquid crystal molecules 514 are tilted by applying a voltage, and how the luminance changes under the condition that two polarizing plates (polarizer 521 and analyzer 522) are arranged in a crossed Nicol configuration.

[0026] In FIG. 9, the luminance of light passing through each of the regions (1) to (3) is expressed as luminance ∝ sin 2 It is expressed as (Δndπ / λ), where Δn is the refractive index anisotropy of the liquid crystal molecules 514, d is the cell gap (the thickness of the liquid crystal layer 513), and λ is the wavelength of the incident light L11. The maximum brightness is obtained when Δndπ / λ=π / 2, that is, Δnd=λ / 2.

[0027] In region (1), no voltage is applied to the liquid crystal layer 513. The liquid crystal molecules 514 are aligned almost perpendicular to the substrate of the liquid crystal panel. Linearly polarized light L12 incident on the liquid crystal layer 513 passes through the liquid crystal layer 513 with almost no effect from the liquid crystal molecules 514. With two polarizers in a crossed Nicol arrangement, the final output light displays black.

[0028] In region (2), a certain voltage is applied to the liquid crystal layer 513, and the liquid crystal molecules 514 are tilted to a certain degree with respect to the substrate of the liquid crystal panel. When the liquid crystal molecules 514 are tilted to a certain degree in this manner, a phase difference occurs, and the polarization state of the polarized light L12 incident on the liquid crystal layer 513 changes from linearly polarized light to elliptically polarized light. Under the condition that the two polarizing plates are arranged in a crossed Nicol state, the final output light is a mixture of light that can pass through the analyzer 522 and light that cannot pass through, resulting in a gray (half-tone) display.

[0029] In region (3), a higher voltage is applied to the liquid crystal layer 513 than in region (2), and the liquid crystal molecules 514 are aligned almost parallel to the substrate of the liquid crystal panel. In this case, the refractive index anisotropy Δn of the liquid crystal molecules 514 is maximized, and when Δnd=λ / 2 is set, the polarized light L12 incident on the liquid crystal layer 513 becomes linearly polarized light rotated by 90° within the liquid crystal layer 513. Under the condition that the two polarizing plates are arranged in a crossed Nicol configuration, the intensity-modulated light L13 passes through the analyzer 522, and the final output light displays white.

[0030] (Optical action of phase modulation type liquid crystal panel) 10 and 11 show an overview of a phase modulation type liquid crystal panel as the optical phase modulation element 1. Fig. 10 shows a schematic diagram of the configuration of the optical phase modulation element 1 viewed from the front direction and the polarization state of light. Fig. 11 shows a schematic diagram of the configuration in a cross section of the optical phase modulation element 1 and the polarization state of light. Figs. 10 and 11 show a configuration example in which the optical phase modulation element 1 is a transmissive VA mode liquid crystal panel.

[0031] 11, similar to the configuration of the luminance modulation method in FIG. 9, a polarizer 521 is arranged in the light incident direction with respect to the optical phase modulation element 1, but an analyzer 522 is not arranged in the light output direction. Similarly to the configuration of the luminance modulation method in FIG. 9, the optical phase modulation element 1 is configured such that a liquid crystal layer 513 is sandwiched between a plurality of pixel electrodes 511 and a plurality of pixel electrodes 512 facing each other. The liquid crystal layer 513 has a plurality of liquid crystal molecules 514. The liquid crystal layer 513 is arranged such that the plurality of liquid crystal molecules 514 are aligned in a predetermined direction.

[0032] The polarizer 521 emits polarized light L12 that is polarized in a predetermined polarization direction from the unpolarized incident light L11. The alignment direction of the liquid crystal molecules 514 is, for example, parallel to the polarization direction of the polarized light L12 when viewed from the front, as shown in Fig. 10. The inclination in the cross section of the liquid crystal molecules 514 changes according to the voltage applied between the opposing pixel electrodes 511 and 512, as shown in Fig. 11. As a result, the phase of the phase-modulated light L14 finally emitted from the optical phase modulation element 1 changes according to the applied voltage.

[0033] In a phase modulation type liquid crystal panel, only the phase of light changes depending on the tilt of liquid crystal molecules 514, but the polarization does not change, so the brightness does not change. Figure 11 shows how the incident linearly polarized polarized light L12 changes and how the phase changes when voltage is applied and liquid crystal molecules 514 tilt.

[0034] Consider the case where linearly polarized light L12 is incident on a liquid crystal panel in agreement with the director of liquid crystal molecules 514, as shown in Fig. 10. In Fig. 11, the phase of light passing through each of regions (1) to (3) changes by one wavelength at Δnd=λ.

[0035] In region (1), no voltage is applied to the liquid crystal layer 513. The liquid crystal molecules 514 are aligned almost perpendicular to the substrate of the liquid crystal panel. The polarization direction of the linearly polarized light L12 incident on the liquid crystal layer 513 coincides with the director of the liquid crystal molecules 514, so the polarization does not change. If the refractive index of the liquid crystal layer 513 in region (1) is n1, the phase delay Δnd of the output light from the optical phase modulation element 1 is n1d.

[0036] In region (2), a certain amount of voltage is applied to the liquid crystal layer 513, and the liquid crystal molecules 514 are tilted to a certain degree with respect to the substrate of the liquid crystal panel. The polarization direction of the linearly polarized light L12 incident on the liquid crystal layer 513 coincides with the director of the liquid crystal molecules 514, so the polarization does not change. When the liquid crystal molecules 514 are tilted, the refractive index of the liquid crystal layer 513 in region (2) is obtained by subtracting the refractive index of the ordinary ray no from the refractive index of the extraordinary ray ne for the amount of tilt of the liquid crystal molecules 514. If the refractive index of the liquid crystal layer 513 in region (2) is n2, the phase delay Δnd of the output light from the optical phase modulation element 1 is n2d.

[0037] In the region (3), a higher voltage is applied to the liquid crystal layer 513 than in the region (2), and the liquid crystal molecules 514 are aligned almost parallel to the substrate of the liquid crystal panel. The polarization direction of the linearly polarized light L12 incident on the liquid crystal layer 513 coincides with the director of the liquid crystal molecules 514, so the polarization does not change. When the liquid crystal molecules 514 are parallel to the substrate of the liquid crystal panel, the refractive index anisotropy Δn of the liquid crystal molecules 514 is maximum. The refractive index of the liquid crystal layer 513 is the refractive index ne of the extraordinary ray minus the refractive index no of the ordinary ray. If the refractive index of the liquid crystal layer 513 in the region (3) is n3, the phase delay Δnd of the output light from the optical phase modulation element 1 is n3d. When Δnd=λ is set, the phase of the phase-modulated light L14 finally output from the optical phase modulation element 1 changes by one wavelength when comparing the region (1) where the liquid crystal molecules 514 are standing and the region (3) where the liquid crystal molecules 514 are lying down.

[0038] (Single-plate color optical phase modulation element) Patent Documents 1 and 2 propose a technique for generating illumination light of the three primary colors (red, green, and blue) required for color display in a projector using a different optical phase modulation element for each color. Meanwhile, Patent Document 3 proposes a technique for generating illumination light of the three primary colors required for color display using one optical phase modulation element (single-plate type color optical phase modulation element).

[0039] FIG. 12 shows an overview of a single-plate color optical phase modulation element 100 according to a comparative example. In the single-plate color optical phase modulation element 100, for example, a single liquid crystal panel filled with a single liquid crystal material is divided into a red (R) region 110R, a green (G) region 110G, and a blue (B) region 110B within its surface, and R, G, and B color light is irradiated onto each color region. Then, a phase distribution pattern (phase hologram) according to the wavelength of each color light is calculated and displayed in each color region, thereby obtaining a desired reconstructed image 100. This reconstructed image 100 can be used as illumination light for a light intensity modulation element in a luminance modulation type projector.

[0040] However, in the single-panel color optical phase modulation element 100 according to the comparative example, since a single liquid crystal material is filled in, the phase modulation characteristics and light resistance are different in each of the R region 110R, G region 110G, and B region 110B due to the nature of the liquid crystal material, as described below, which leads to a decrease in performance and reliability. The issues for each color region will be explained below.

[0041] (R region 110R: phase modulation amount) FIG. 13 shows an example of the wavelength dispersion characteristic of the refractive index anisotropy Δn of a typical liquid crystal material. Generally, the longer the wavelength of a liquid crystal material, the smaller the value of the refractive index anisotropy Δn. In other words, for red light with a long wavelength (near 630 nm), the refractive index anisotropy Δn of the liquid crystal material is small.

[0042] To perform 2π phase modulation in an optical phase modulation element, Δnd=λ is required, so the design value of the refractive index anisotropy Δn of the liquid crystal material must be determined from the refractive index anisotropy Δn at the wavelength of the R region 110R. In that case, the B region 110B can be designed with Δnd=λ (550 nm), but if it is designed to match the refractive index anisotropy Δn of the R region 110R, Δnd>λ (550 nm) will be exceeded, and a high Δn liquid crystal material must be used, resulting in a trade-off with light resistance. In addition, the response speed of the liquid crystal material depends on the viscosity of the liquid crystal material. The higher the viscosity of the liquid crystal material, the slower the response speed. Generally, liquid crystal materials with high Δn have high viscosity, which affects the response speed.

[0043] (B area 110B: Light resistance deterioration) Liquid crystal panels are deteriorated by short-wavelength blue light. In other words, when a liquid crystal panel is irradiated with strong blue light for a long time, free radicals are generated from the surrounding materials, such as the sealant and encapsulant, which are dissolved in the liquid crystal material, or impurities from the environment. It is considered that the generated free radicals will deteriorate the characteristics of the liquid crystal panel by cutting the chemical bonds of the liquid crystal material. In other words, light resistance is a particular issue for the B region 110B, and when used in a single-panel color optical phase modulation element 100, there is a possibility that only the B region 110B will deteriorate locally. For this reason, it is necessary to make the B region 110B specifically high light resistance. In designing the liquid crystal material, it is effective to reduce the value of the refractive index anisotropy Δn.

[0044] (G area 110G: Visibility of image quality errors) FIG. 14 shows an example of a relative luminous efficiency curve. Even if the light has the same intensity, the human eye perceives the intensity differently depending on the wavelength, and this perception is modeled as a relative luminosity curve. FIG. 14 shows the relative luminosity curve at wavelengths λ=380 nm to 780 nm that humans can sense, and the relative luminosity at wavelengths λ=555 nm is normalized as the maximum value. Since the human luminosity for green wavelengths is high, if there is an abnormality in the phase distribution pattern displayed in the G region 110G in the single-panel color optical phase modulation element 100, it is difficult to hide it, and it becomes difficult to obtain a reproduced image 100 with sufficient display performance. Specifically, when injecting the liquid crystal material, an injection port is formed, but after the liquid crystal is sealed, it is sealed with resin. If impurities from the sealant get on the G region 110G, it will deteriorate locally, the display of the phase distribution pattern will become insufficient, and a high-quality reproduced image 100 will not be obtained.

[0045] <1. First embodiment> [1.1 Overview (example of planar configuration of optical phase modulation element)] The basic structure of the optical phase modulation element according to the first embodiment of the present disclosure may be a configuration in which a liquid crystal material is sealed between a pair of opposing substrates, similar to the optical phase modulation element 1 shown in FIG. 11. The optical phase modulation element according to the first embodiment is configured to be made up of one liquid crystal panel, similar to the single-plate color optical phase modulation element 100 according to the comparative example shown in FIG. 12, has a plurality of color regions corresponding to a plurality of color lights, and is configured to be capable of obtaining a desired reconstructed image 100 by displaying a phase distribution pattern according to the wavelength of each color light in each color region. The single-plate color optical phase modulation element 100 according to the comparative example is configured to have a single liquid crystal material sealed in one liquid crystal panel, but the optical phase modulation element according to the first embodiment is configured to have a plurality of liquid crystal materials sealed in. The optical phase modulation element according to the first embodiment has a plurality of divided regions provided in different regions from each other in the in-plane direction. The divided regions are sealed with liquid crystal materials having refractive index anisotropy Δn different from each other. Each of the divided regions displays a phase distribution pattern for at least one color having a different wavelength from each other.

[0046] A specific configuration example of the optical phase modulation element according to the first embodiment will be described below. Note that, in the following, a configuration example in which the color regions displaying the phase distribution pattern are R, G, and B is shown, but the colors are not limited to these. In addition, the color regions may be two or four or more.

[0047] (First configuration example) Fig. 15 is a schematic diagram showing a first example of an in-plane structure of an optical phase modulation element according to the first embodiment. The configuration example shown in Fig. 15 corresponds to the configurations of Examples 1 and 4 described later.

[0048] The optical phase modulation element 1A shown in FIG. 15 has a first divided region 21 and a second divided region 22 as a plurality of divided regions.

[0049] In the optical phase modulation element 1A, the first division region 21 has an R region (red region) 10R and a G region (green region) 10G. The R region 10R is illuminated by red light from, for example, a laser light source (not shown), and displays a phase distribution pattern for red optimized for the peak wavelength of the red light. The G region 10G is illuminated by green light from, for example, a laser light source (not shown), and displays a phase distribution pattern for green optimized for the peak wavelength of the green light.

[0050] The second division region 22 has a B region (blue region) 10B. The B region 10B is illuminated by blue light from, for example, a laser light source (not shown), and displays a phase distribution pattern for blue optimized for the peak wavelength of the blue light.

[0051] A seal 41 is formed around each of the first divided region 21 and the second divided region 22, separating them from each other. Liquid crystal materials having different refractive index anisotropy Δn are filled in the first divided region 21 and the second divided region 22. That is, in the optical phase modulation element 1A shown in FIG. 15, the liquid crystal material in the R region 10R and the G region 10G is different from the liquid crystal material in the B region 10B.

[0052] When the refractive index anisotropy of the liquid crystal material filled in the first division region 21 is ΔnR,G and the refractive index anisotropy of the liquid crystal material filled in the second division region 22 is ΔnB, the optical phase modulation element 1A has the following characteristics at the same wavelength (for example, λ=550 nm): ΔnR,G>ΔnB It is desirable to satisfy the following.

[0053] That is, it is desirable to inject a high Δn liquid crystal material into the R region 10R and the G region 10G. In the first division region 21, it is desirable to form a liquid crystal injection port in the R region 10R and seal it with the sealant 42. As a result, in the first division region 21, a sufficient phase modulation amount that matches the R region 10R can be realized, and local deterioration due to impurities from the sealant 42 in the G region 10G can also be prevented. If a drop injection process is used, the sealant 42 is not necessary. In this case, it is sufficient to expect the effect of only the phase modulation amount of the R region 10R. For the B region 10B, a liquid crystal material that satisfies Δnd=λ in the vicinity of the peak wavelength of blue light (for example, λ=450 nm) should be selected. In other words, a liquid crystal material with a lower Δn can be selected for the B region 10B, which is advantageous in terms of light resistance. Also, according to this configuration example, high quality can be achieved without increasing the number of processes by simply changing the seal pattern.

[0054] The areas of the R region 10R, the G region 10G, and the B region 10B may be the same or different. The areas of the R region 10R, the G region 10G, and the B region 10B may be determined according to the amount of light emitted by the light sources of the respective colors R, G, and B. A highly coherent laser light source is preferable as the light source, but an LED (Light Emitting Diode) or a phosphor light source may also be used.

[0055] (Second configuration example) Fig. 16 is a schematic diagram showing a second example of the in-plane structure of the optical phase modulation element according to the first embodiment. The configuration example shown in Fig. 16 corresponds to the configurations of Examples 1 and 4 described later.

[0056] The optical phase modulation element 1B shown in FIG. 16 has a first divided region 21, a second divided region 22, and a third divided region 23 as a plurality of divided regions.

[0057] In the optical phase modulation element 1B, the first division region 21 has an R region 10R. The R region 10R is illuminated by red light from, for example, a laser light source (not shown), and displays a red phase distribution pattern optimized for the peak wavelength of the red light.

[0058] In the optical phase modulation element 1B, the second division region 22 has a G region 10G. The G region 10G is illuminated by green light from, for example, a laser light source (not shown), and displays a phase distribution pattern for green optimized for the peak wavelength of the green light.

[0059] In the optical phase modulation element 1B, the third divided region 23 has a region B 10B. The region B 10B is illuminated by blue light from, for example, a laser light source (not shown), and displays a blue phase distribution pattern optimized for the peak wavelength of the blue light.

[0060] A seal 41 is formed around each of the first division region 21, the second division region 22, and the third division region 23, separating them from one another. Liquid crystal materials having different refractive index anisotropy Δn are filled in each of the first division region 21, the second division region 22, and the third division region 23. That is, in the optical phase modulation element 1B shown in FIG. 16, the liquid crystal materials in the R region 10R, the G region 10G, and the B region 10B are different from one another. In each of the R region 10R, the G region 10G, and the B region 10B, the liquid crystal injection port is sealed with a sealant 42. If a drop injection process is used, the sealant 42 is not necessary.

[0061] In the optical phase modulation element 1B, when the refractive index anisotropy of the liquid crystal material filled in the first divided region 21 is ΔnR, the refractive index anisotropy of the liquid crystal material filled in the second divided region 22 is ΔnG, and the refractive index anisotropy of the liquid crystal material filled in the third divided region 23 is ΔnB, at the same wavelength (for example, λ=550 nm), ΔnR ≥ ΔnG > ΔnB It is desirable to satisfy the following.

[0062] This makes it possible to realize excellent performance in terms of the above-mentioned light resistance, reliability, and phase modulation amount. This configuration example has the advantage that the liquid crystal material can be optimized in each of the R region 10R, G region 10G, and B region 10B.

[0063] The areas of the R region 10R, the G region 10G, and the B region 10B may be the same or different. The areas of the R region 10R, the G region 10G, and the B region 10B may be determined according to the amount of light of the light source of each color of R, G, and B. A highly coherent laser light source is preferable as the light source, but an LED or a phosphor light source may also be used.

[0064] (Third configuration example) Fig. 17 is a schematic diagram showing a third example of the in-plane structure of the optical phase modulation element according to the first embodiment. The configuration example shown in Fig. 17 corresponds to the configuration of Example 3, which will be described later.

[0065] The basic configuration of the optical phase modulation element 1C shown in FIG. 17 is the same as that of the optical phase modulation element 1A shown in FIG. 15, but the area of ​​each divided region is different from that of the optical phase modulation element 1A shown in FIG. 15. In the optical phase modulation element 1C shown in FIG. 17, the area of ​​the second divided region 22 having the B region 10B is set to 1 / 3 or more of the entire effective display region in the plane. As described above, the B region 10B is easily deteriorated by blue light. As for the deterioration of the B region 10B, deterioration occurs locally due to the variation in the incident light in the plane. Therefore, a larger area of ​​the B region 10B can ensure an undegraded region, making it possible to obtain a high-quality reproduced image for a long time.

[0066] Similarly, in the optical phase modulation element 1B shown in FIG. 16, it is preferable that the area of ​​the third divided region 23 having the B region 10B is equal to or greater than ⅓ of the entire effective display region within the plane.

[0067] (Fourth configuration example) In the optical phase modulation element according to the first to third configuration examples, an alignment film may be formed on the surface of the pair of opposing substrates that contacts the liquid crystal layer. In this case, the alignment film may be provided corresponding to each of the multiple divided regions. In this case, the alignment film may be configured to include multiple alignment films made of different materials. For example, it is desirable to use an organic material for the alignment film corresponding to the divided region having the R region 10R and the G region 10G, and an inorganic material for the alignment film corresponding to the divided region having the B region 10B. The division of each alignment film can be realized, for example, by separating the steps of an inkjet or mask process. In particular, by using an inorganic alignment film for the divided region having the B region 10B, it is possible to further increase light resistance.

[0068] (Fifth Configuration Example) 18 and 19 show schematic diagrams of first and second modified examples of the in-plane structure of the optical phase modulation element according to the first embodiment.

[0069] In the optical phase modulation elements according to the first to fourth configuration examples, each of the plurality of divided regions may have a structure in which at least a part of the divided regions has a curved shape in the in-plane direction.

[0070] An optical phase modulation element 1D according to a first modified example shown in Fig. 18 is configured such that a part of the first divided region 21 is curved and the entire second divided region 22 is curved, as compared to the configuration of the optical phase modulation element 1A shown in Fig. 15. In the optical phase modulation element 1D, the second divided region 22 is formed in a central region within the plane, and a seal 41 is formed around the second divided region 22 to divide the second divided region 22 and the first divided region 21.

[0071] An optical phase modulation element 1E according to a second modified example shown in Fig. 19 is configured such that the first division region 21 and parts of the second division region 22 are curved and the whole of the third division region 23 is curved, compared to the configuration of the optical phase modulation element 1B shown in Fig. 16. In the optical phase modulation element 1E, the third division region 23 is formed in a central region within the surface, and a seal 41 is formed around the third division region 23, thereby dividing the third division region 23 into the first division region 21 and the second division region 22.

[0072] The shape of each divided region may be various shapes other than those shown in Figures 15 to 19. The ability to form the shape of each divided region in various patterns provides an advantage in that it increases the degree of freedom in design and makes it possible to apply the technology of the present disclosure even when there are restrictions on the arrangement of light sources, for example.

[0073] The method of injecting the liquid crystal material may be a process called ODF (One Drop Fill), in which the liquid crystal material is dropped onto one substrate using a seal pattern, and then the other substrate is placed on top and bonded, or a vacuum injection process, or both. This allows a configuration that does not use a sealant 42, such as the optical phase modulation element 1D shown in FIG. 18.

[0074] [effect] As described above, according to the optical phase modulation element of the first embodiment, liquid crystal materials having different refractive index anisotropies are filled into each of the multiple divided regions, and each of the divided regions displays phase distribution patterns for colors having different wavelengths, thereby making it possible to achieve high performance and high reliability.

[0075] The optical phase modulation element of the first embodiment can ensure a sufficient amount of phase modulation in the R region 10R, and even when the optical phase modulation element is illuminated with a high-brightness RGB light source, deterioration due to changes over time in the B region 10B can be suppressed, enabling stable light control and a clear reproduced image to be obtained.

[0076] The effects described in this specification are merely examples and are not limiting, and other effects may be achieved. The same applies to the effects of other embodiments described below.

[0077] [1.2 Example of display device configuration] As described above, the optical phase modulation element according to the first embodiment has a plurality of color regions into which light of each wavelength of R, G, and B is incident, and each color region displays a phase distribution pattern optimized by the peak wavelength of each color. As a calculation method of phase distribution data for displaying a phase distribution pattern, there are a diffraction type method in which the phase distribution is derived from a diffraction approximation formula, and a refractive type method in which the phase distribution is derived as a free-form lens instead of diffraction, and either calculation method may be used.

[0078] The light source is preferably an RGB laser with high coherence, but LEDs or phosphors may also be used. For example, the R, G, and B light emitted from the light source is expanded by a collimator lens to become parallel light, and is used as illumination light for each color area of ​​the optical phase modulation element. A reconstructed image is displayed at a specified location by phase-modulating the laser light incident on the optical phase modulation element, but differences in wavelength must be taken into consideration so that the reconstructed image is the same size when each color is combined. Each pixel of the optical phase modulation element can perform continuous phase modulation from 0 to 2π by controlling the retardation of the liquid crystal according to the input signal.

[0079] FIG. 20 shows a schematic configuration example of a projector 101 as a display device using the optical phase modulation element according to the first embodiment.

[0080] The projector 101 includes an image signal output device 60, an intensity modulation pattern calculation circuit 61, a phase distribution pattern calculation circuit 62, an optical phase modulation element drive circuit 63, and an optical intensity modulation element drive circuit 64. The projector 101 further includes an optical phase modulation element 10, a light source unit 30, a beam shaping optical system 32, an optical intensity modulation element 51, a polarization separation element (PBS) 52, and a projection lens 53.

[0081] 20 shows an example in which the optical phase modulation element 10 is configured as a reflective liquid crystal panel. The in-plane structure of the optical phase modulation element 10 may be any of the configuration examples shown in the above-mentioned Figs. 15 to 19. The optical phase modulation element 10 has a plurality of color regions, and each color region displays a phase distribution pattern optimized according to the peak wavelength of each color.

[0082] The light source unit 30 has a plurality of light sources 31 each having a different peak wavelength. The light sources 31 are, for example, laser light sources. The beam shaping optical system 32 spatially separates and shapes the color light of each peak wavelength emitted from each light source 31, and illuminates each color region of the optical phase modulation element 10 with the color light of each peak wavelength.

[0083] The image signal output device 60 outputs an image signal to an intensity modulation pattern calculation circuit 61 and a phase distribution pattern calculation circuit 62. The phase distribution pattern calculation circuit 62 calculates a phase distribution pattern to be displayed by the optical phase modulation element 10 based on the image signal. The phase distribution pattern to be displayed by the optical phase modulation element 10 is a phase distribution pattern capable of forming an illumination image having a luminance distribution according to the image to be displayed.

[0084] In the phase distribution pattern calculation circuit 62, for example, a portion of the image with a luminance level equal to or higher than a threshold value is extracted from the image signal, and a phase distribution pattern is calculated by repeated FFT (Fast Fourier Transform) calculation. Here, the phase distribution pattern calculation circuit 62 holds information on the peak wavelength of the light source unit 30 and information on the division pattern of each color region of the optical phase modulation element 10 in advance, and calculates a phase distribution pattern optimized for each peak wavelength and each color region as the phase distribution pattern. In addition, the phase distribution pattern calculation circuit 62 outputs an illumination light intensity modulation pattern signal to the intensity modulation pattern calculation circuit 61. The illumination light intensity modulation pattern signal represents information on the luminance distribution of the illumination image formed by the phase distribution pattern.

[0085] The optical phase modulation element driving circuit 63 drives the optical phase modulation element 10 to display the phase distribution pattern calculated by the phase distribution pattern calculation circuit 62. The intensity modulation pattern calculation circuit 61 calculates an intensity modulation pattern for generating an image to be displayed by the optical intensity modulation element 51 based on the image signal. At this time, the intensity modulation pattern is calculated taking into account information on the luminance distribution of the illumination image by the optical phase modulation element 10.

[0086] The light-intensity modulation element driving circuit 64 drives the light-intensity modulation element 51 so as to generate the intensity modulation pattern calculated by the intensity modulation pattern calculation circuit 61 .

[0087] The polarization separation element 52 transmits a first polarization component of the incident light and reflects a second polarization component orthogonal to the first polarization component. The illumination image formed by the optical phase modulation element 10 is irradiated as illumination light to the optical intensity modulation element 51 via the polarization separation element 52. The optical intensity modulation element 51 performs intensity modulation on the illumination light based on the intensity modulation pattern calculated by the intensity modulation pattern calculation circuit 61 to generate a projection image. As described above, the intensity modulation pattern calculated by the intensity modulation pattern calculation circuit 61 includes information on the luminance distribution of the illumination image by the optical phase modulation element 10, so that the optical intensity modulation element 51 generates a projection image that reproduces the original image signal.

[0088] The projection image generated by the light intensity modulation element 51 is emitted by the polarization separation element 52 toward the projection lens 53. The projection lens 53 is a projection optical system including a plurality of lenses, and projects the projection image generated by the light intensity modulation element 51 onto a projection surface such as a screen 50.

[0089] [1.3 Example of cross-sectional structure of optical phase modulation element] FIG. 21 shows a schematic cross-sectional configuration example of the optical phase modulation element according to the first embodiment.

[0090] The configuration example of Fig. 21 shows an example in which the optical phase modulation element 201 is configured with a reflective liquid crystal panel. The in-plane structure of the optical phase modulation element 201 shown in Fig. 21 may be any of the configuration examples shown in Figs. 15 to 19 above. The optical phase modulation element 201 has a plurality of color regions, and each color region displays a phase distribution pattern optimized according to the peak wavelength of each color.

[0091] The optical phase modulation element 201 includes a glass substrate 210, a drive substrate 220, and a liquid crystal material 240. The liquid crystal material 240 is sealed between the glass substrate 210 and the drive substrate 220 by a sealant 230 and a spacer 231. The liquid crystal material 240 is, for example, a vertically aligned liquid crystal.

[0092] The glass substrate 210 has a transparent electrode 211 having optical transparency. The transparent electrode 211 and an alignment film 212 are formed on the glass substrate 210. The alignment film 212 may be an organic film such as polyimide, or a film such as SiO 2 Inorganic alignment films such as silicon oxide are used. Inorganic alignment films are preferable for light resistance and heat resistance.

[0093] The driving substrate 220 is made of a single crystal semiconductor substrate such as silicon having a light-reflecting electrode 221 with a pixel structure. In the driving substrate 220, a driving circuit is formed on the single crystal silicon substrate, the driving circuit being made of a transistor made of a complementary metal oxide semiconductor (CMOS) or an n-channel metal oxide semiconductor (MOS) and a capacitor. A pixel structure is formed on the driving circuit with a metal film such as Al (aluminum) or Ag (silver). This metal film serves as the light-reflecting electrode 221, and serves both as a light-reflecting film and an electrode for a voltage applied to the liquid crystal material 240. An alignment film 222 is formed on the surface of the light-reflecting electrode 221. The alignment film 222 may be an organic film such as polyimide or a thin film such as SiO 2 Inorganic alignment films such as silicon oxide are used. Inorganic alignment films are preferable for light resistance and heat resistance.

[0094] [1.4 Working Example] FIG. 22 shows the types of liquid crystal materials used in the optical phase modulation elements according to the embodiments described below.

[0095] The optical phase modulation element according to the first embodiment has a plurality of divided regions provided in different regions in the in-plane direction. Liquid crystal materials having different refractive index anisotropy Δn are filled in the plurality of divided regions. Figure 22 shows the values ​​of refractive index anisotropy Δn for each wavelength of R (λ=630 nm), G (λ=550 nm), and B (λ=450 nm) as the characteristics of each of the liquid crystal materials A, B, and C used in the following examples.

[0096] [Example 1] The in-plane structure of the optical phase modulation element according to the first embodiment is as shown in FIG. 15. FIG. 23 shows a schematic in-plane structure of the optical phase modulation element according to the comparative example. Both the optical phase modulation elements according to the comparative example and the first embodiment are configured with liquid crystal panels. The optical phase modulation element according to the first embodiment includes a first divided region 21 having an R region 10R and a G region 10G, and a second divided region 22 having a B region 10B. In contrast, the optical phase modulation element according to the comparative example does not have divided regions, and has a structure having an R region 10R, a G region 10G, and a B region 10B in a single region.

[0097] FIG. 24 shows the values ​​of the cell gap d (thickness of the liquid crystal layer) of the optical phase modulation elements according to the comparative example and the first embodiment, and the types and physical properties (Δn) of the liquid crystal materials.

[0098] In the optical phase modulation elements according to the comparative example and the first embodiment, the liquid crystal material used in the liquid crystal layer is a nematic liquid crystal material having negative dielectric anisotropy.

[0099] In the optical phase modulation element according to the comparative example, liquid crystal material A was injected into the entire in-plane region (R region 10R, G region 10G, and B region 10B) under a vacuum environment. In the optical phase modulation element according to the example 1, liquid crystal material A was injected into the first division region 21 (R region 10R and G region 10G), and liquid crystal material B was injected into the second division region 22 (B region 10B) under a vacuum environment. After that, the injection port was sealed with a sealant 42 made of a UV-curable resin. It is also possible to configure the device without forming an injection port and without using the sealant 42. In this case, the liquid crystal is injected using, for example, a process called ODF, in which liquid crystal material is dropped onto one substrate and another substrate is placed on top and bonded.

[0100] (Evaluation Results) Phase modulation amount Fig. 25 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to the comparative example. Fig. 26 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to Example 1. Fig. 27 shows the voltage values ​​required to modulate the phase by 2π in the optical phase modulation elements according to the comparative example and Example 1.

[0101] 25 and 26 show the results of measuring the amount of phase modulation for each color region at 5V. FIG. 27 shows the voltage values ​​for each color region required to modulate the phase by 2π, obtained from the results of measuring in FIGS. 25 and 26. In the optical phase modulation element according to the comparative example, the same liquid crystal material is used in each color region, so the value of refractive index anisotropy Δn in the B region 10B is larger than that in the R region 10R and the G region 10G due to wavelength dispersion. However, since the amount of phase modulation is sufficient at 2π, in the optical phase modulation element according to the first embodiment, a liquid crystal material with low Δn is used only in the B region 10B.

[0102] Light resistance Next, a light resistance test was performed. The optical phase modulation elements of the comparative example and the example 1 were placed in a test machine for liquid crystal projectors, and the transmittance in the B region 10B was measured. FIG. 28 shows the results of the light resistance test for the optical phase modulation element of the comparative example. FIG. 29 shows the results of the light resistance test for the optical phase modulation element of the example 1. In FIG. 28 and FIG. 29, the vertical axis indicates the maximum transmittance of each optical phase modulation element, and the horizontal axis indicates the usage time (light irradiation time). In the optical phase modulation element of the comparative example, the transmittance of the B region 10B decreased significantly with time, but in the optical phase modulation element of the example 1, no decrease in transmittance was observed. In the configuration of the optical phase modulation element of the example 1, a liquid crystal material with a small refractive index anisotropy Δn is used in the B region 10B. In general, it is considered that the smaller the value of the refractive index anisotropy Δn of a liquid crystal material, the less likely it is to be photodecomposed, and therefore the light deterioration is small. According to the optical phase modulation element of the example 1, no deterioration due to long-term use is observed, and a good phase distribution pattern can be displayed.

[0103] Reliability testing Fig. 30 shows the results of a reliability test on the optical phase modulation elements according to the comparative example and Example 1. Fig. 30 shows the results of an accelerated test conducted under environmental test conditions of high temperature and high humidity of 60°C and 90%. When an image was reconstructed from the phase distribution pattern, a good, clear image was obtained even after 500 hours had passed in the optical phase modulation element according to Example 1. Since degradation is easily noticeable in the G region 10G, a good phase distribution pattern can be displayed by using a structure that does not contact the sealant 42.

[0104] [Example 2] The in-plane structure of the optical phase modulation element according to the second embodiment is as shown in FIG. 16. The in-plane structure of the optical phase modulation element according to the comparative example is as shown in FIG. 23. Both the optical phase modulation elements according to the comparative example and the second embodiment are configured with a liquid crystal panel. The optical phase modulation element according to the second embodiment includes a first divided region 21 having an R region 10R, a second divided region 22 having a G region 10G, and a third divided region 23 having a B region 10B. In contrast, the optical phase modulation element according to the comparative example does not have divided regions, and has a structure having an R region 10R, a G region 10G, and a B region 10B in a single region.

[0105] FIG. 24 shows the values ​​of the cell gap d (thickness of the liquid crystal layer) of the optical phase modulation elements according to the comparative example and the second embodiment, and the types and physical properties (Δn) of the liquid crystal materials.

[0106] In the optical phase modulation elements according to the comparative example and the embodiment 2, the liquid crystal material used in the liquid crystal layer is a nematic liquid crystal material having negative dielectric anisotropy.

[0107] In the optical phase modulation element according to the comparative example, the liquid crystal material A was injected in the entire in-plane region (R region 10R, G region 10G, and B region 10B) under a vacuum environment. In the optical phase modulation element according to the second embodiment, the liquid crystal material A was injected in the first division region 21 (R region 10R), the liquid crystal material C in the second division region 22 (G region 10G), and the liquid crystal material B in the third division region 23 (B region 10B) under a vacuum environment. After that, the injection port was sealed with a sealant 42 made of a UV-curable resin. It is also possible to form a configuration without forming an injection port and without using the sealant 42. In this case, the liquid crystal is injected using, for example, a process called ODF, in which the liquid crystal material is dropped on one substrate and another substrate is superimposed and bonded.

[0108] (Evaluation Results) Phase modulation amount Fig. 32 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to the comparative example. Fig. 33 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to Example 2. Fig. 34 shows the voltage values ​​required to modulate the phase by 2π in the optical phase modulation elements according to the comparative example and Example 2.

[0109] 32 and 33 show the results of measuring the amount of phase modulation for each color region at 5V. FIG. 34 shows the voltage values ​​for each color region required to modulate the phase by 2π, obtained from the results of measuring in FIGS. 32 and 33. In the optical phase modulation element according to the comparative example, the same liquid crystal material is used for each color region, so the B region 10B and the G region 10G have a larger refractive index anisotropy Δn value due to wavelength dispersion than the R region 10R. However, since the amount of phase modulation is sufficient at 2π, in the optical phase modulation element according to the second embodiment, a liquid crystal material with a lower Δn is used in the B region 10B and the G region 10G compared to the R region 10R.

[0110] Lightfastness Next, a light resistance test was performed. The optical phase modulation elements of the comparative example and the embodiment 2 were placed in a test machine for liquid crystal projectors, and the transmittance in the B region 10B was measured. FIG. 35 shows the results of the light resistance test for the optical phase modulation element of the comparative example. FIG. 36 shows the results of the light resistance test for the optical phase modulation element of the embodiment 2. In FIG. 35 and FIG. 36, the vertical axis indicates the maximum transmittance of each optical phase modulation element, and the horizontal axis indicates the usage time (light irradiation time). In the optical phase modulation element of the comparative example, the transmittance of the B region 10B decreased significantly with time, but in the optical phase modulation element of the embodiment 2, no decrease in transmittance was observed. In the configuration of the optical phase modulation element of the embodiment 2, a liquid crystal material with a small refractive index anisotropy Δn is used in the B region 10B. In general, it is considered that the smaller the value of the refractive index anisotropy Δn of a liquid crystal material, the less likely it is to be photodecomposed, and therefore the light deterioration is small. According to the optical phase modulation element of the embodiment 2, no deterioration due to long-term use is observed, and a good phase distribution pattern can be displayed.

[0111] [Example 3] The in-plane structure of the optical phase modulation element according to the third embodiment is as shown in FIG. 17. FIG. 23 shows a schematic in-plane structure of the optical phase modulation element according to the comparative example. Both the optical phase modulation elements according to the comparative example and the third embodiment are composed of a liquid crystal panel. The optical phase modulation element according to the third embodiment includes a first division region 21 having an R region 10R and a G region 10G, and a second division region 22 having a B region 10B. In contrast, the optical phase modulation element according to the comparative example does not have division regions, and has a structure having an R region 10R, a G region 10G, and a B region 10B in a single region. In addition, in the optical phase modulation element according to the third embodiment, the area of ​​the second division region 22 having the B region 10B is 1 / 3 or more of the total effective display region in the plane.

[0112] FIG. 37 shows the values ​​of the cell gap d (thickness of the liquid crystal layer) of the optical phase modulation elements according to the comparative example and the third embodiment, and the types and physical properties (Δn) of the liquid crystal materials.

[0113] In the optical phase modulation elements according to the comparative example and the third embodiment, the liquid crystal material used in the liquid crystal layer is a nematic liquid crystal material having negative dielectric anisotropy.

[0114] In the optical phase modulation element according to the comparative example, liquid crystal material A was injected into the entire in-plane region (R region 10R, G region 10G, and B region 10B) under a vacuum environment. In the optical phase modulation element according to the example 3, liquid crystal material A was injected into the first division region 21 (R region 10R and G region 10G), and liquid crystal material B was injected into the second division region 22 (B region 10B) under a vacuum environment. After that, the injection port was sealed with a sealant 42 made of a UV-curable resin. It is also possible to form a configuration without forming an injection port and without using the sealant 42. In this case, the liquid crystal is injected using, for example, a process called ODF, in which liquid crystal material is dropped onto one substrate, and another substrate is placed on top and bonded.

[0115] (Evaluation Results) Phase modulation amount Fig. 38 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to the comparative example. Fig. 39 shows the voltage characteristics of the phase modulation amount of the optical phase modulation element according to Example 3. Fig. 40 shows the voltage values ​​required to modulate the phase by 2π in the optical phase modulation elements according to the comparative example and Example 3.

[0116] 38 and 39 show the results of measuring the amount of phase modulation for each color region at 5V. FIG. 40 shows the voltage values ​​for each color region required to modulate the phase by 2π, obtained from the results of measuring in FIGS. 38 and 39. In the optical phase modulation element according to the comparative example, the same liquid crystal material is used in each color region, so the value of refractive index anisotropy Δn in the B region 10B is larger than that in the R region 10R and the G region 10G due to wavelength dispersion. However, since the amount of phase modulation is sufficient at 2π, in the optical phase modulation element according to the third embodiment, a liquid crystal material with low Δn is used only in the B region 10B.

[0117] Light resistance Next, a light resistance test was performed. The optical phase modulation elements of the comparative example and the embodiment 3 were placed in a test machine for liquid crystal projectors, and the transmittance in the B region 10B was measured. FIG. 28 shows the results of the light resistance test for the optical phase modulation element of the comparative example. FIG. 41 shows the results of the light resistance test for the optical phase modulation element of the embodiment 3. In FIG. 41, the vertical axis shows the maximum transmittance of each optical phase modulation element, and the horizontal axis shows the usage time (light irradiation time). In the optical phase modulation element of the comparative example, the transmittance of the B region 10B significantly decreased with time, but in the optical phase modulation element of the embodiment 3, as in the embodiment 1 (FIG. 29), no decrease in transmittance was observed. In the configuration of the optical phase modulation element of the embodiment 3, a liquid crystal material with a small refractive index anisotropy Δn is used in the B region 10B, as in the optical phase modulation element of the embodiment 1. In general, it is considered that the smaller the value of the refractive index anisotropy Δn of a liquid crystal material is, the less likely it is to be photodecomposed, and therefore the light deterioration is small.

[0118] However, when the irradiation time was extended and the test was performed for about three times the time of the comparative example, it was found that the transmittance of the B region 10B also decreased little by little in the optical phase modulation element according to Example 3. In other words, although the deterioration time of the B region 10B can be extended by material design, it is not permanent and deterioration will inevitably occur eventually.

[0119] Fig. 42 shows the evaluation results of the reconstructed images in the optical phase modulation elements according to the comparative example, the example 1, and the example 3. Fig. 42 shows the evaluation results of the reconstructed images at the initial stage and after a certain period of time. The image quality rank of 5 is the best, and the lower the number, the worse the image quality tends to be.

[0120] In the optical phase modulation element according to the comparative example, image degradation was observed at an early stage. In contrast, in the optical phase modulation element according to Example 1, the appearance was good for a long time. In the optical phase modulation element according to Example 3, the appearance was even better for a long time than in the optical phase modulation element according to Example 1. The reason for this is that in the optical phase modulation element according to Example 3, the area of ​​the B region 10B is made larger than that of the optical phase modulation element according to Example 1. In the optical phase modulation element, there is also variation in the incident light within the plane, so that degradation occurs locally within the plane, and the degradation of the center of each color region becomes large. In other words, a larger area can ensure an area that is not deteriorated, making it possible to obtain a high-quality reproduced image for a long time.

[0121] [Example 4] The optical phase modulation element according to Example 4 is composed of a liquid crystal panel. The in-plane structure of the optical phase modulation element according to Example 4 is as shown in FIG. 15. The optical phase modulation element according to Example 4 has a different material for the alignment film from the optical phase modulation element according to Example 1. The optical phase modulation element according to Example 1 has an alignment film made of the same material in all color regions. In contrast, the optical phase modulation element according to Example 4 has an alignment film made of polyimide, which is an organic material, corresponding to the divided region having the R region 10R and the G region 10G, and an alignment film made of an inorganic material corresponding to the divided region having the B region 10B. In addition, in the optical phase modulation element according to Example 4, a positive type liquid crystal material a is injected as the liquid crystal material into the R region 10R and the G region 10G, and a negative type liquid crystal material B is injected into the B region 10B. The value of the refractive index anisotropy Δn of the liquid crystal material a is the same as that of the liquid crystal material A (see FIG. 22).

[0122] In the optical phase modulation element according to the fourth embodiment, the B region 10B is formed by masking the R region 10R and the G region 10G with SiO 2 was evaporated. After that, printing was performed so that a polyimide material could be formed in the R region 10R and the G region 10G. Of course, it may be formed using a process such as inkjet. After that, the B region 10B was masked and a photo-alignment process was performed. Of course, it may be formed using a mask rubbing method. After that, a seal pattern as shown in Figure 15 was formed, and a positive type liquid crystal material a was injected into the R region 10R and the G region 10, and a negative type liquid crystal material B was injected into the B region 10B.

[0123] FIG. 43 shows the value of the cell gap d (thickness of the liquid crystal layer) of the optical phase modulation element according to Example 4, and the type and physical property value (Δn) of the liquid crystal material.

[0124] In the optical phase modulation element according to Example 4, the liquid crystal material a was injected into the first divided region 21 (the R region 10R and the G region 10G) and the liquid crystal material B was injected into the second divided region 22 (the B region 10B) under a vacuum environment. After that, the injection port was sealed with a sealant 42 made of a UV-curable resin.

[0125] As a result, an optical phase modulation element with good image quality and good light resistance was realized. Generally, polyimide alignment films, which have strong anchoring, have good alignment but are weak against light. By using a polyimide alignment film in the G region 10G, which has high visibility, the alignment is improved, resulting in the formation of a good phase distribution pattern and the realization of a good reproduced image.

[0126] Furthermore, by forming an inorganic alignment film having high light resistance in the B region 10B, it is possible to reproduce a good reproduced image without deterioration due to light for a long period of time.

[0127] [1.5 Modifications] In the above description, a configuration example in which the optical phase modulation element is applied to a display device has been given, but the optical phase modulation element according to the technology of the present disclosure can be applied to devices other than display devices. For example, it can be applied to a laser processing machine. An example of a laser processing machine is a machine that processes a metal pattern such as an electrode by irradiating a laser beam. In addition, there is a laser soldering machine that performs soldering by irradiating a laser beam.

[0128] FIG. 44 shows the wavelength characteristics of light absorptance in metals. As shown in FIG. 44, the wavelength characteristics of light absorptivity differ depending on the type of metal. For example, gold (Au) and copper (Cu) have a higher light absorptivity with a blue laser than with a near-infrared laser. For this reason, gold and copper are more efficiently processed using a blue laser. In addition, since the wavelength characteristics of light absorptivity differ depending on the type of metal, multiple metals of different materials can be processed simultaneously by using multiple laser beams with different wavelengths. In such a case, multiple metals of different materials can be processed simultaneously by generating a pattern of multiple laser beams with different wavelengths using an optical phase modulation element according to the technology disclosed herein.

[0129] <2. Application Examples> [2.1 First application example] The technology according to the present disclosure can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, a robot, a construction machine, an agricultural machine (tractor), etc.

[0130] Fig. 45 is a block diagram showing a schematic configuration example of a vehicle control system 7000 which is an example of a mobile object control system to which the technology according to the present disclosure can be applied. The vehicle control system 7000 includes a plurality of electronic control units connected via a communication network 7010. In the example shown in Fig. 45, the vehicle control system 7000 includes a drive system control unit 7100, a body system control unit 7200, a battery control unit 7300, an outside-vehicle information detection unit 7400, an inside-vehicle information detection unit 7500, and an integrated control unit 7600. The communication network 7010 connecting these multiple control units may be an in-vehicle communication network conforming to any standard such as CAN (Controller Area Network), LIN (Local Interconnect Network), LAN (Local Area Network), or FlexRay (registered trademark).

[0131] Each control unit includes a microcomputer that performs arithmetic processing according to various programs, a storage unit that stores the programs executed by the microcomputer or parameters used in various calculations, and a drive circuit that drives various devices to be controlled. Each control unit includes a network I / F for communicating with other control units via a communication network 7010, and a communication I / F for communicating with devices or sensors inside and outside the vehicle by wired communication or wireless communication. In FIG. 45, a microcomputer 7610, a general-purpose communication I / F 7620, a dedicated communication I / F 7630, a positioning unit 7640, a beacon receiving unit 7650, an in-vehicle device I / F 7660, an audio / video output unit 7670, an in-vehicle network I / F 7680, and a storage unit 7690 are illustrated as the functional configuration of the integrated control unit 7600. Other control units also include a microcomputer, a communication I / F, a storage unit, and the like.

[0132] The drivetrain control unit 7100 controls the operation of devices related to the drivetrain of the vehicle according to various programs. For example, the drivetrain control unit 7100 functions as a control device for a drive force generating device for generating a drive force of the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force of the vehicle. The drivetrain control unit 7100 may also function as a control device such as an ABS (Antilock Brake System) or an ESC (Electronic Stability Control).

[0133] A vehicle state detection unit 7110 is connected to the drive system control unit 7100. The vehicle state detection unit 7110 includes at least one of a gyro sensor that detects the angular velocity of the axial rotational motion of the vehicle body, an acceleration sensor that detects the acceleration of the vehicle, or a sensor for detecting the amount of operation of an accelerator pedal, the amount of operation of a brake pedal, the steering angle of a steering wheel, the engine rotation speed, or the rotation speed of wheels, for example. The drive system control unit 7100 performs arithmetic processing using signals input from the vehicle state detection unit 7110, and controls the internal combustion engine, the drive motor, the electric power steering device, the brake device, etc.

[0134] The body system control unit 7200 controls the operation of various devices mounted on the vehicle body according to various programs. For example, the body system control unit 7200 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as head lamps, back lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals of various switches transmitted from a portable device that replaces a key may be input to the body system control unit 7200. The body system control unit 7200 receives the input of these radio waves or signals and controls the door lock device, power window device, lamps, and the like of the vehicle.

[0135] The battery control unit 7300 controls the secondary battery 7310, which is a power supply source for the drive motor, according to various programs. For example, information such as battery temperature, battery output voltage, or remaining capacity of the battery is input to the battery control unit 7300 from a battery device equipped with the secondary battery 7310. The battery control unit 7300 performs calculation processing using these signals, and controls the temperature regulation of the secondary battery 7310 or controls a cooling device or the like equipped in the battery device.

[0136] The outside-vehicle information detection unit 7400 detects information outside the vehicle equipped with the vehicle control system 7000. For example, at least one of an imaging unit 7410 and an outside-vehicle information detection unit 7420 is connected to the outside-vehicle information detection unit 7400. The imaging unit 7410 includes at least one of a ToF (Time Of Flight) camera, a stereo camera, a monocular camera, an infrared camera, and other cameras. The outside-vehicle information detection unit 7420 includes at least one of an environmental sensor for detecting the current weather or climate, or a surrounding information detection sensor for detecting other vehicles, obstacles, pedestrians, and the like around the vehicle equipped with the vehicle control system 7000.

[0137] The environmental sensor may be, for example, at least one of a raindrop sensor that detects rain, a fog sensor that detects fog, a sunshine sensor that detects the degree of sunshine, and a snow sensor that detects snowfall. The surrounding information detection sensor may be at least one of an ultrasonic sensor, a radar device, and a LIDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging) device. The imaging unit 7410 and the outside vehicle information detection unit 7420 may be provided as independent sensors or devices, or may be provided as a device in which multiple sensors or devices are integrated.

[0138] Here, FIG. 46 shows an example of the installation positions of the imaging unit 7410 and the vehicle exterior information detection unit 7420. The imaging units 7910, 7912, 7914, 7916, and 7918 are provided, for example, at least one of the front nose, side mirrors, rear bumper, back door, and upper part of the windshield in the vehicle interior of the vehicle 7900. The imaging unit 7910 provided on the front nose and the imaging unit 7918 provided on the upper part of the windshield in the vehicle interior mainly acquire images of the front of the vehicle 7900. The imaging units 7912 and 7914 provided on the side mirrors mainly acquire images of the sides of the vehicle 7900. The imaging unit 7916 provided on the rear bumper or back door mainly acquires images of the rear of the vehicle 7900. The imaging unit 7918 provided on the upper part of the windshield in the vehicle interior is mainly used to detect a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, a lane, or the like.

[0139] 46 shows an example of the imaging ranges of the imaging units 7910, 7912, 7914, and 7916. Imaging range a indicates the imaging range of the imaging unit 7910 provided on the front nose, imaging ranges b and c indicate the imaging ranges of the imaging units 7912 and 7914 provided on the side mirrors, and imaging range d indicates the imaging range of the imaging unit 7916 provided on the rear bumper or back door. For example, image data captured by the imaging units 7910, 7912, 7914, and 7916 are superimposed to obtain an overhead image of the vehicle 7900 viewed from above.

[0140] The outside information detection units 7920, 7922, 7924, 7926, 7928, and 7930 provided on the front, rear, sides, and corners of the vehicle 7900 and on the upper part of the windshield inside the vehicle cabin may be, for example, ultrasonic sensors or radar devices. The outside information detection units 7920, 7926, and 7930 provided on the front nose, rear bumper, back door, and on the upper part of the windshield inside the vehicle cabin of the vehicle 7900 may be, for example, LIDAR devices. These outside information detection units 7920 to 7930 are mainly used to detect preceding vehicles, pedestrians, obstacles, and the like.

[0141] Returning to FIG. 45, the description will be continued. The outside-vehicle information detection unit 7400 causes the imaging unit 7410 to capture an image outside the vehicle, and receives the captured image data. The outside-vehicle information detection unit 7400 also receives detection information from the outside-vehicle information detection unit 7420 connected thereto. When the outside-vehicle information detection unit 7420 is an ultrasonic sensor, a radar device, or a LIDAR device, the outside-vehicle information detection unit 7400 transmits ultrasonic waves or electromagnetic waves, and receives information on the received reflected waves. The outside-vehicle information detection unit 7400 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, or characters on the road surface, based on the received information. The outside-vehicle information detection unit 7400 may perform environment recognition processing for recognizing rainfall, fog, road surface conditions, and the like, based on the received information. The outside-vehicle information detection unit 7400 may calculate the distance to an object outside the vehicle based on the received information.

[0142] Furthermore, the outside vehicle information detection unit 7400 may perform image recognition processing or distance detection processing to recognize people, cars, obstacles, signs, or characters on the road surface, based on the received image data. The outside vehicle information detection unit 7400 may perform processing such as distortion correction or position adjustment on the received image data, and may generate an overhead image or a panoramic image by synthesizing image data captured by different imaging units 7410. The outside vehicle information detection unit 7400 may perform viewpoint conversion processing using image data captured by different imaging units 7410.

[0143] The in-vehicle information detection unit 7500 detects information inside the vehicle. For example, a driver state detection unit 7510 that detects the state of the driver is connected to the in-vehicle information detection unit 7500. The driver state detection unit 7510 may include a camera that captures an image of the driver, a biosensor that detects the bioinformation of the driver, or a microphone that collects sound in the vehicle cabin. The biosensor is provided, for example, on the seat or steering wheel, and detects the bioinformation of a passenger sitting in the seat or a driver gripping the steering wheel. The in-vehicle information detection unit 7500 may calculate the degree of fatigue or concentration of the driver based on the detection information input from the driver state detection unit 7510, or may determine whether the driver is dozing. The in-vehicle information detection unit 7500 may perform processing such as noise canceling processing on the collected sound signal.

[0144] The integrated control unit 7600 controls the overall operation of the vehicle control system 7000 according to various programs. The input unit 7800 is connected to the integrated control unit 7600. The input unit 7800 is realized by a device that can be operated by an occupant to input, such as a touch panel, a button, a microphone, a switch, or a lever. Data obtained by voice recognition of a voice input by a microphone may be input to the integrated control unit 7600. The input unit 7800 may be, for example, a remote control device using infrared or other radio waves, or an externally connected device such as a mobile phone or a PDA (Personal Digital Assistant) that supports the operation of the vehicle control system 7000. The input unit 7800 may be, for example, a camera, in which case the occupant can input information by gestures. Alternatively, data obtained by detecting the movement of a wearable device worn by the occupant may be input. Furthermore, the input unit 7800 may include, for example, an input control circuit that generates an input signal based on information input by the occupant using the above-mentioned input unit 7800 and outputs the input signal to the integrated control unit 7600. A passenger or the like operates the input unit 7800 to input various data to the vehicle control system 7000 and to instruct processing operations.

[0145] The storage unit 7690 may include a ROM (Read Only Memory) that stores various programs executed by the microcomputer, and a RAM (Random Access Memory) that stores various parameters, calculation results, sensor values, etc. The storage unit 7690 may be realized by a magnetic storage device such as an HDD (Hard Disc Drive), a semiconductor storage device, an optical storage device, or a magneto-optical storage device, etc.

[0146] The general-purpose communication I / F 7620 is a general-purpose communication I / F that mediates communication between various devices present in the external environment 7750. The general-purpose communication I / F 7620 may implement a cellular communication protocol such as GSM (registered trademark), WiMAX (registered trademark), LTE (registered trademark) (Long Term Evolution) or LTE-Advanced (LTE-A), or other wireless communication protocols such as wireless LAN (also called Wi-Fi (registered trademark)) and Bluetooth (registered trademark). The general-purpose communication I / F 7620 may connect to a device (e.g., an application server or a control server) present on an external network (e.g., the Internet, a cloud network, or a carrier-specific network) via, for example, a base station or an access point. The general-purpose communication I / F 7620 may also connect to a terminal (e.g., a driver's, pedestrian's, or store's terminal, or a Machine Type Communication (MTC) terminal) present in the vicinity of the vehicle using, for example, a Peer To Peer (P2P) technology.

[0147] The dedicated communication I / F 7630 is a communication I / F that supports a communication protocol designed for use in a vehicle. The dedicated communication I / F 7630 may implement a standard protocol such as WAVE (Wireless Access in Vehicle Environment), which is a combination of a lower layer IEEE802.11p and a higher layer IEEE1609, DSRC (Dedicated Short Range Communications), or a cellular communication protocol. The dedicated communication I / F 7630 typically performs V2X communication, which is a concept including one or more of vehicle-to-vehicle communication, vehicle-to-infrastructure communication, vehicle-to-home communication, and vehicle-to-pedestrian communication.

[0148] The positioning unit 7640 performs positioning by receiving, for example, a GNSS signal from a Global Navigation Satellite System (GNSS) satellite (for example, a GPS signal from a Global Positioning System (GPS) satellite) and generates position information including the latitude, longitude, and altitude of the vehicle. The positioning unit 7640 may identify the current position by exchanging signals with a wireless access point, or may obtain position information from a terminal such as a mobile phone, PHS, or smartphone having a positioning function.

[0149] The beacon receiving unit 7650 receives, for example, radio waves or electromagnetic waves transmitted from radio stations or the like installed on the road, and acquires information such as the current location, congestion, road closure, required time, etc. The function of the beacon receiving unit 7650 may be included in the dedicated communication I / F 7630 described above.

[0150] The in-vehicle device I / F 7660 is a communication interface that mediates a connection between the microcomputer 7610 and various in-vehicle devices 7760 present in the vehicle. The in-vehicle device I / F 7660 may establish a wireless connection using a wireless communication protocol such as wireless LAN, Bluetooth (registered trademark), NFC (Near Field Communication), or WUSB (Wireless USB). The in-vehicle device I / F 7660 may also establish a wired connection such as USB (Universal Serial Bus), HDMI (High-Definition Multimedia Interface), or MHL (Mobile High-definition Link) via a connection terminal (and a cable, if necessary) not shown. The in-vehicle device 7760 may include at least one of a mobile device or a wearable device owned by a passenger, or an information device carried or attached to a vehicle. The in-vehicle device 7760 may also include a navigation device that searches for a route to an arbitrary destination. The in-vehicle equipment I / F 7660 exchanges control signals and data signals with these in-vehicle equipment 7760.

[0151] The in-vehicle network I / F 7680 is an interface that mediates communication between the microcomputer 7610 and the communication network 7010. The in-vehicle network I / F 7680 transmits and receives signals in accordance with a predetermined protocol supported by the communication network 7010.

[0152] The microcomputer 7610 of the integrated control unit 7600 controls the vehicle control system 7000 according to various programs based on information acquired through at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. For example, the microcomputer 7610 may calculate a control target value of a driving force generating device, a steering mechanism, or a braking device based on the acquired information inside and outside the vehicle, and output a control command to the drive system control unit 7100. For example, the microcomputer 7610 may perform cooperative control for the purpose of realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, vehicle speed maintenance driving, vehicle collision warning, vehicle lane departure warning, etc. In addition, the microcomputer 7610 may perform cooperative control for the purpose of autonomous driving, in which the vehicle travels autonomously without relying on driver operation, by controlling a driving force generating device, a steering mechanism, a braking device, etc. based on information acquired about the vehicle's surroundings.

[0153] The microcomputer 7610 may generate three-dimensional distance information between the vehicle and objects such as surrounding structures and people, and create local map information including peripheral information of the current position of the vehicle, based on information acquired via at least one of the general-purpose communication I / F 7620, the dedicated communication I / F 7630, the positioning unit 7640, the beacon receiving unit 7650, the in-vehicle device I / F 7660, and the in-vehicle network I / F 7680. The microcomputer 7610 may also predict dangers such as vehicle collisions, the approach of pedestrians, or entry into a closed road, based on the acquired information, and generate a warning signal. The warning signal may be, for example, a signal for generating a warning sound or turning on a warning lamp.

[0154] The audio / image output unit 7670 transmits at least one of audio and image output signals to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of FIG. 45, an audio speaker 7710, a display unit 7720, and an instrument panel 7730 are illustrated as output devices. The display unit 7720 may include at least one of an on-board display and a head-up display, for example. The display unit 7720 may have an AR (Augmented Reality) display function. The output device may be other devices such as headphones, a wearable device such as a glasses-type display worn by the passenger, a projector, or a lamp, other than these devices. When the output device is a display device, the display device visually displays the results obtained by various processes performed by the microcomputer 7610 or information received from other control units in various formats such as text, image, table, graph, etc. When the output device is an audio output device, the audio output device converts an audio signal consisting of reproduced audio data or acoustic data into an analog signal and audibly outputs it.

[0155] In the example shown in FIG. 45, at least two control units connected via the communication network 7010 may be integrated into one control unit. Alternatively, each control unit may be composed of multiple control units. Furthermore, the vehicle control system 7000 may include another control unit not shown. In the above description, some or all of the functions performed by any control unit may be provided by another control unit. In other words, as long as information is transmitted and received via the communication network 7010, a predetermined arithmetic processing may be performed by any control unit. Similarly, a sensor or device connected to any control unit may be connected to another control unit, and multiple control units may transmit and receive detection information to each other via the communication network 7010.

[0156] In the vehicle control system 7000 described above, the technology of the present disclosure can be applied to the display unit 7720.

[0157] [2.2 Second application example] The technology disclosed herein may be applied to an endoscopic surgery system.

[0158] Fig. 47 is a diagram showing an example of a schematic configuration of an endoscopic surgery system 5000 to which the technology according to the present disclosure can be applied. Fig. 47 shows a state in which an operator (doctor) 5067 performs surgery on a patient 5071 on a patient bed 5069 using the endoscopic surgery system 5000. As shown in the figure, the endoscopic surgery system 5000 is composed of an endoscope 5001, other surgical tools 5017, a support arm device 5027 that supports the endoscope 5001, and a cart 5037 on which various devices for endoscopic surgery are mounted.

[0159] In endoscopic surgery, instead of cutting the abdominal wall to open the abdomen, a cylindrical opening instrument called trocar 5025a to 5025d is punctured into the abdominal wall. Then, the lens barrel 5003 of the endoscope 5001 and other surgical instruments 5017 are inserted into the body cavity of the patient 5071 from the trocar 5025a to 5025d. In the illustrated example, as the other surgical instruments 5017, a pneumoperitoneum tube 5019, an energy treatment instrument 5021, and forceps 5023 are inserted into the body cavity of the patient 5071. The energy treatment instrument 5021 is a treatment instrument that performs incision and peeling of tissue, sealing of blood vessels, etc. by high-frequency current or ultrasonic vibration. However, the illustrated surgical instrument 5017 is merely an example, and various surgical instruments generally used in endoscopic surgery, such as a suction cup and a retractor, may be used as the surgical instrument 5017.

[0160] An image of the operation site in the body cavity of the patient 5071 photographed by the endoscope 5001 is displayed on the display device 5041. The surgeon 5067 performs treatment such as excising the affected area using the energy treatment tool 5021 and the forceps 5023 while viewing the image of the operation site displayed on the display device 5041 in real time. Although not shown in the figure, the pneumoperitoneum tube 5019, the energy treatment tool 5021, and the forceps 5023 are supported by the surgeon 5067 or an assistant during surgery.

[0161] (Support arm device) The support arm device 5027 includes an arm portion 5031 extending from a base portion 5029. In the example shown, the arm portion 5031 is composed of joint portions 5033a, 5033b, and 5033c and links 5035a and 5035b, and is driven under the control of an arm control device 5045. The arm portion 5031 supports the endoscope 5001, and controls its position and attitude. This allows the endoscope 5001 to be stably fixed in position.

[0162] (Endoscopy) The endoscope 5001 is composed of a lens barrel 5003, a region of a predetermined length from the tip of which is inserted into a body cavity of a patient 5071, and a camera head 5005 connected to the base end of the lens barrel 5003. In the illustrated example, the endoscope 5001 is configured as a so-called rigid lens barrel having a rigid lens barrel 5003, but the endoscope 5001 may be configured as a so-called flexible lens barrel having a flexible lens barrel 5003.

[0163] An opening into which an objective lens is fitted is provided at the tip of the lens barrel 5003. A light source device 5043 is connected to the endoscope 5001, and light generated by the light source device 5043 is guided to the tip of the lens barrel by a light guide extending inside the lens barrel 5003, and is irradiated via the objective lens toward an observation target in the body cavity of the patient 5071. The endoscope 5001 may be a direct-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0164] An optical system and an imaging element are provided inside the camera head 5005, and reflected light (observation light) from an observation target is collected on the imaging element by the optical system. The imaging element photoelectrically converts the observation light to generate an electrical signal corresponding to the observation light, i.e., an image signal corresponding to an observation image. The image signal is transmitted to a camera control unit (CCU) 5039 as RAW data. The camera head 5005 is equipped with a function for adjusting the magnification and focal length by appropriately driving the optical system.

[0165] For example, to support stereoscopic vision (3D display), a plurality of imaging elements may be provided in the camera head 5005. In this case, a plurality of relay optical systems are provided inside the lens barrel 5003 to guide observation light to each of the plurality of imaging elements.

[0166] (Various devices mounted on the cart) The CCU 5039 is configured with a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and performs overall control of the operations of the endoscope 5001 and the display device 5041. Specifically, the CCU 5039 performs various image processing, such as development processing (demosaic processing), on the image signal received from the camera head 5005 in order to display an image based on the image signal. The CCU 5039 provides the image signal that has been subjected to the image processing to the display device 5041. The CCU 5039 also transmits a control signal to the camera head 5005 to control its drive. The control signal may include information on imaging conditions, such as magnification and focal length.

[0167] The display device 5041 displays an image based on an image signal that has been subjected to image processing by the CCU 5039 under the control of the CCU 5039. When the endoscope 5001 is compatible with high-resolution imaging such as 4K (3840 horizontal pixels x 2160 vertical pixels) or 8K (7680 horizontal pixels x 4320 vertical pixels) and / or compatible with 3D display, the display device 5041 may be capable of displaying high resolution and / or 3D display, respectively. When compatible with high-resolution imaging such as 4K or 8K, a display device 5041 with a size of 55 inches or more can be used to provide a more immersive feeling. In addition, multiple display devices 5041 with different resolutions and sizes may be provided depending on the application.

[0168] The light source device 5043 is composed of a light source such as an LED (light emitting diode) and supplies the endoscope 5001 with irradiation light when photographing the surgical site.

[0169] The arm control device 5045 is constituted by a processor such as a CPU, and operates according to a prescribed program to control the driving of the arm portion 5031 of the support arm device 5027 according to a prescribed control method.

[0170] The input device 5047 is an input interface for the endoscopic surgery system 5000. A user can input various information and instructions to the endoscopic surgery system 5000 via the input device 5047. For example, the user inputs various information related to surgery, such as physical information of a patient and information about a surgical procedure, via the input device 5047. In addition, for example, the user inputs, via the input device 5047, an instruction to drive the arm unit 5031, an instruction to change the imaging conditions (type of irradiation light, magnification, focal length, etc.) of the endoscope 5001, an instruction to drive the energy treatment tool 5021, etc.

[0171] The type of the input device 5047 is not limited, and the input device 5047 may be any of various known input devices. For example, a mouse, a keyboard, a touch panel, a switch, a foot switch 5057, and / or a lever may be applied as the input device 5047. When a touch panel is used as the input device 5047, the touch panel may be provided on a display surface of the display device 5041.

[0172] Alternatively, the input device 5047 is a device worn by the user, such as a glasses-type wearable device or a head mounted display (HMD), and various inputs are made according to the user's gestures and gaze detected by these devices. The input device 5047 also includes a camera capable of detecting the user's movements, and various inputs are made according to the user's gestures and gaze detected from the image captured by the camera. The input device 5047 also includes a microphone capable of collecting the user's voice, and various inputs are made by voice via the microphone. In this way, the input device 5047 is configured to be able to input various information in a non-contact manner, and thus it becomes possible for a user (e.g., the surgeon 5067) belonging to a clean area to operate a device belonging to an unclean area in a non-contact manner. In addition, the user can operate the device without taking his / her hands off the surgical tool he / she is holding, which improves the user's convenience.

[0173] The treatment tool control device 5049 controls the driving of the energy treatment tool 5021 for cauterizing tissue, incising, sealing blood vessels, etc. The insufflation device 5051 sends gas into the body cavity of the patient 5071 through the insufflation tube 5019 in order to secure the field of view of the endoscope 5001 and the working space of the surgeon. The recorder 5053 is a device capable of recording various information related to the surgery. The printer 5055 is a device capable of printing various information related to the surgery in various formats such as text, image, or graph.

[0174] Below, the particularly characteristic configuration of the endoscopic surgery system 5000 will be described in further detail.

[0175] (Support arm device) The support arm device 5027 includes a base 5029, which is a base, and an arm 5031 extending from the base 5029. In the illustrated example, the arm 5031 includes a plurality of joints 5033a, 5033b, and 5033c, and a plurality of links 5035a and 5035b connected by the joint 5033b. However, in FIG. 47, for the sake of simplicity, the configuration of the arm 5031 is simplified. In practice, the shapes, number, and arrangement of the joints 5033a to 5033c and the links 5035a and 5035b, as well as the directions of the rotation axes of the joints 5033a to 5033c, can be appropriately set so that the arm 5031 has a desired degree of freedom. For example, the arm 5031 can be preferably configured to have six or more degrees of freedom. This allows the endoscope 5001 to be moved freely within the movable range of the arm portion 5031, making it possible to insert the lens barrel 5003 of the endoscope 5001 into the body cavity of the patient 5071 from a desired direction.

[0176] The joints 5033a to 5033c are provided with actuators, and the joints 5033a to 5033c are configured to be rotatable around a predetermined rotation axis by driving the actuators. The drive of the actuators is controlled by the arm control device 5045, whereby the rotation angles of the joints 5033a to 5033c are controlled, and the drive of the arm unit 5031 is controlled. This allows control of the position and attitude of the endoscope 5001. At this time, the arm control device 5045 can control the drive of the arm unit 5031 by various known control methods such as force control or position control.

[0177] For example, the surgeon 5067 may appropriately input an operation via the input device 5047 (including the foot switch 5057), and the drive of the arm unit 5031 may be appropriately controlled by the arm control device 5045 in response to the operation input, thereby controlling the position and posture of the endoscope 5001. Through this control, the endoscope 5001 at the tip of the arm unit 5031 may be moved from one position to another, and then fixedly supported at the position after the movement. The arm unit 5031 may be operated in a so-called master-slave manner. In this case, the arm unit 5031 may be remotely operated by a user via the input device 5047 installed in a location away from the operating room.

[0178] Furthermore, when force control is applied, the arm control device 5045 may perform so-called power assist control, in which the actuators of the joints 5033a to 5033c are driven so that the arm unit 5031 moves smoothly in response to an external force from the user. This allows the arm unit 5031 to be moved with a relatively light force when the user moves the arm unit 5031 while directly touching the arm unit 5031. This makes it possible to move the endoscope 5001 more intuitively and with a simpler operation, improving user convenience.

[0179] Generally, in endoscopic surgery, the endoscope 5001 is supported by a doctor called a scopist. By contrast, by using the support arm device 5027, the position of the endoscope 5001 can be fixed more reliably without relying on human hands, so that an image of the surgical site can be obtained stably and the surgery can be performed smoothly.

[0180] The arm control device 5045 does not necessarily have to be provided on the cart 5037. Also, the arm control device 5045 does not necessarily have to be one device. For example, the arm control device 5045 may be provided on each of the joints 5033a to 5033c of the arm section 5031 of the support arm device 5027, and the drive control of the arm section 5031 may be realized by the multiple arm control devices 5045 cooperating with each other.

[0181] (Light source device) The light source device 5043 supplies the endoscope 5001 with irradiation light for photographing the surgical site. The light source device 5043 is composed of a white light source composed of, for example, an LED, a laser light source, or a combination of these. In this case, when the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so that the light source device 5043 can adjust the white balance of the captured image. In this case, it is also possible to capture images corresponding to each of the RGB colors in a time-division manner by irradiating the observation target with laser light from each of the RGB laser light sources in a time-division manner and controlling the driving of the image sensor of the camera head 5005 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter to the image sensor.

[0182] Furthermore, the light source device 5043 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the driving of the image sensor of the camera head 5005 in synchronization with the timing of the change in the light intensity to obtain images in a time-division manner and synthesizing the images, it is possible to generate an image with a high dynamic range that is free of so-called blocked-up shadows and blown-out highlights.

[0183] The light source device 5043 may be configured to supply light of a predetermined wavelength band corresponding to the special light observation. In the special light observation, for example, by utilizing the wavelength dependency of light absorption in body tissue, a narrow band light is irradiated compared to the irradiated light (i.e., white light) during normal observation, and a predetermined tissue such as blood vessels on the mucous membrane surface is photographed with high contrast, so-called narrow band imaging is performed. Alternatively, in the special light observation, a fluorescent observation may be performed in which an image is obtained by fluorescence generated by irradiating an excitation light. In the fluorescent observation, an excitation light is irradiated to a body tissue and the fluorescence from the body tissue is observed (autofluorescence observation), or a reagent such as indocyanine green (ICG) is locally injected into the body tissue and an excitation light corresponding to the fluorescence wavelength of the reagent is irradiated to the body tissue to obtain a fluorescent image. The light source device 5043 may be configured to supply narrow band light and / or excitation light corresponding to such special light observation.

[0184] (Camera head and CCU) The functions of the camera head 5005 and the CCU 5039 of the endoscope 5001 will be described in more detail with reference to Fig. 48. Fig. 48 is a block diagram showing an example of the functional configuration of the camera head 5005 and the CCU 5039 shown in Fig. 47.

[0185] 48, the camera head 5005 has, as its functions, a lens unit 5007, an imaging unit 5009, a drive unit 5011, a communication unit 5013, and a camera head control unit 5015. The CCU 5039 has, as its functions, a communication unit 5059, an image processing unit 5061, and a control unit 5063. The camera head 5005 and the CCU 5039 are connected by a transmission cable 5065 so as to be able to communicate in both directions.

[0186] First, the functional configuration of the camera head 5005 will be described. The lens unit 5007 is an optical system provided at a connection portion with the lens barrel 5003. Observation light taken in from the tip of the lens barrel 5003 is guided to the camera head 5005 and enters the lens unit 5007. The lens unit 5007 is configured by combining a plurality of lenses including a zoom lens and a focus lens. The optical characteristics of the lens unit 5007 are adjusted so as to focus the observation light on the light receiving surface of the image pickup element of the image pickup section 5009. In addition, the zoom lens and the focus lens are configured so that their positions on the optical axis can be moved in order to adjust the magnification and focus of the captured image.

[0187] The imaging unit 5009 is composed of an imaging element, and is disposed after the lens unit 5007. Observation light passing through the lens unit 5007 is collected on the light receiving surface of the imaging element, and an image signal corresponding to the observed image is generated by photoelectric conversion. The image signal generated by the imaging unit 5009 is provided to the communication unit 5013.

[0188] The imaging element constituting the imaging unit 5009 is, for example, a CMOS (Complementary Metal Oxide Semiconductor) type image sensor capable of color imaging having a Bayer array. The imaging element may be capable of capturing high-resolution images of, for example, 4K or higher. By obtaining a high-resolution image of the surgical site, the surgeon 5067 can grasp the state of the surgical site in more detail, and the surgery can proceed more smoothly.

[0189] The imaging element constituting the imaging unit 5009 is configured to have a pair of imaging elements for acquiring image signals for the right eye and the left eye corresponding to 3D display. The 3D display enables the surgeon 5067 to more accurately grasp the depth of the biological tissue in the surgical site. When the imaging unit 5009 is configured as a multi-plate type, multiple lens units 5007 are provided corresponding to the respective imaging elements.

[0190] Furthermore, the imaging unit 5009 does not necessarily have to be provided in the camera head 5005. For example, the imaging unit 5009 may be provided inside the lens barrel 5003, immediately behind the objective lens.

[0191] The driving section 5011 is configured by an actuator, and moves the zoom lens and focus lens of the lens unit 5007 by a predetermined distance along the optical axis under the control of the camera head control section 5015. This allows the magnification and focus of the image captured by the imaging section 5009 to be appropriately adjusted.

[0192] The communication unit 5013 is configured by a communication device for transmitting and receiving various information to and from the CCU 5039. The communication unit 5013 transmits the image signal obtained from the imaging unit 5009 as RAW data to the CCU 5039 via the transmission cable 5065. At this time, in order to display the captured image of the operation site with low latency, it is preferable that the image signal is transmitted by optical communication. During surgery, the surgeon 5067 performs surgery while observing the condition of the affected area using the captured image, so that a moving image of the operation site is required to be displayed as quickly as possible in real time for a safer and more reliable surgery. When optical communication is performed, the communication unit 5013 is provided with a photoelectric conversion module that converts an electrical signal into an optical signal. The image signal is converted into an optical signal by the photoelectric conversion module and then transmitted to the CCU 5039 via the transmission cable 5065.

[0193] The communication unit 5013 also receives a control signal for controlling the driving of the camera head 5005 from the CCU 5039. The control signal includes information on imaging conditions, such as information for specifying a frame rate of an image to be captured, information for specifying an exposure value at the time of capturing an image, and / or information for specifying a magnification and a focus of an image to be captured. The communication unit 5013 provides the received control signal to the camera head control unit 5015. The control signal from the CCU 5039 may also be transmitted by optical communication. In this case, the communication unit 5013 is provided with a photoelectric conversion module for converting an optical signal into an electrical signal, and the control signal is converted into an electrical signal by the photoelectric conversion module and then provided to the camera head control unit 5015.

[0194] The image capturing conditions such as the frame rate, exposure value, magnification, and focus are automatically set by the control unit 5063 of the CCU 5039 based on the acquired image signal. That is, the endoscope 5001 is equipped with so-called AE (Auto Exposure) function, AF (Auto Focus) function, and AWB (Auto White Balance) function.

[0195] The camera head control unit 5015 controls the driving of the camera head 5005 based on a control signal received from the CCU 5039 via the communication unit 5013. For example, the camera head control unit 5015 controls the driving of the image sensor of the imaging unit 5009 based on information specifying the frame rate of the captured image and / or information specifying the exposure during imaging. Also, for example, the camera head control unit 5015 appropriately moves the zoom lens and focus lens of the lens unit 5007 via the drive unit 5011 based on information specifying the magnification and focus of the captured image. The camera head control unit 5015 may further include a function of storing information for identifying the lens barrel 5003 and the camera head 5005.

[0196] Incidentally, by arranging the components such as the lens unit 5007 and the imaging unit 5009 in a sealed structure that is highly airtight and waterproof, the camera head 5005 can be made resistant to autoclave sterilization.

[0197] Next, the functional configuration of the CCU 5039 will be described. The communication unit 5059 is configured by a communication device for transmitting and receiving various information to and from the camera head 5005. The communication unit 5059 receives an image signal transmitted from the camera head 5005 via the transmission cable 5065. At this time, as described above, the image signal can be suitably transmitted by optical communication. In this case, in correspondence with the optical communication, the communication unit 5059 is provided with a photoelectric conversion module that converts an optical signal into an electrical signal. The communication unit 5059 provides the image signal converted into an electrical signal to the image processing unit 5061.

[0198] Furthermore, the communication unit 5059 transmits, to the camera head 5005, a control signal for controlling the driving of the camera head 5005. This control signal may also be transmitted by optical communication.

[0199] The image processing unit 5061 performs various types of image processing on the image signal, which is RAW data transmitted from the camera head 5005. The image processing includes various known signal processing such as development processing, high image quality processing (band enhancement processing, super-resolution processing, NR (Noise reduction) processing, and / or camera shake correction processing, etc.), and / or enlargement processing (electronic zoom processing), etc. The image processing unit 5061 also performs detection processing on the image signal to perform AE, AF, and AWB.

[0200] The image processing unit 5061 is configured with a processor such as a CPU or a GPU, and the processor operates according to a predetermined program to perform the above-mentioned image processing and detection processing. When the image processing unit 5061 is configured with multiple GPUs, the image processing unit 5061 appropriately divides information related to the image signal and performs image processing in parallel using the multiple GPUs.

[0201] The control unit 5063 performs various controls related to the imaging of the surgical site by the endoscope 5001 and the display of the captured image. For example, the control unit 5063 generates a control signal for controlling the driving of the camera head 5005. At this time, if the imaging conditions are input by the user, the control unit 5063 generates the control signal based on the input by the user. Alternatively, if the endoscope 5001 is equipped with an AE function, an AF function, and an AWB function, the control unit 5063 appropriately calculates an optimal exposure value, focal length, and white balance according to the result of the detection process by the image processing unit 5061, and generates a control signal.

[0202] The control unit 5063 also displays an image of the surgical site on the display device 5041 based on the image signal that has been image-processed by the image processing unit 5061. At this time, the control unit 5063 recognizes various objects in the surgical site image using various image recognition techniques. For example, the control unit 5063 can recognize surgical tools such as forceps, specific living body parts, bleeding, mist when the energy treatment tool 5021 is used, and the like, by detecting the shape and color of the edges of objects included in the surgical site image. When the control unit 5063 displays the image of the surgical site on the display device 5041, it uses the recognition result to superimpose various types of surgery support information on the image of the surgical site. The surgery support information is superimposed and presented to the surgeon 5067, making it possible to proceed with the surgery more safely and reliably.

[0203] The transmission cable 5065 connecting the camera head 5005 and the CCU 5039 is an electrical signal cable corresponding to communication of electrical signals, an optical fiber corresponding to optical communication, or a composite cable of these.

[0204] In the illustrated example, the communication is performed by wire using the transmission cable 5065, but the communication between the camera head 5005 and the CCU 5039 may be performed wirelessly. When the communication between them is performed wirelessly, it becomes unnecessary to lay the transmission cable 5065 in the operating room, and therefore the situation in which the transmission cable 5065 impedes the movement of medical staff in the operating room can be eliminated.

[0205] An example of an endoscopic surgery system 5000 to which the technology according to the present disclosure can be applied has been described above. Note that, although the endoscopic surgery system 5000 has been described here as an example, the system to which the technology according to the present disclosure can be applied is not limited to this example. For example, the technology according to the present disclosure may be applied to a flexible endoscope system for inspection or a microsurgery system.

[0206] The technology according to the present disclosure can be suitably applied to the display device 5041 among the configurations described above.

[0207] <3. Other embodiments> The technology according to the present disclosure is not limited to the above-described embodiment, and various modifications are possible.

[0208] For example, the present technology can be configured as follows. According to the present technology having the following configuration, liquid crystal materials having different refractive index anisotropies are filled into each of the multiple divided regions, and each of the divided regions displays phase distribution patterns for colors having different wavelengths, thereby making it possible to achieve high performance and high reliability.

[0209] (1) a plurality of divided regions, the divided regions being provided in different regions in an in-plane direction, and filled with liquid crystal materials having different refractive index anisotropies, the divided regions each displaying a phase distribution pattern for a color having a different wavelength; Equipped Optical phase modulation element. (2) The plurality of divided regions include a first divided region and a second divided region. The optical phase modulation element according to (1) above. (3) the first divided region has a red region displaying a phase distribution pattern for red and a green region displaying a phase distribution pattern for green, The second division region has a blue region for displaying a phase distribution pattern for blue. The optical phase modulation element according to (2) above. (4) When the refractive index anisotropy of the liquid crystal material filled in the first divided region is ΔnR,G and the refractive index anisotropy of the liquid crystal material filled in the second divided region is ΔnB, the refractive index anisotropy at the same wavelength is expressed as follows: ΔnR,G>ΔnB Fulfill The optical phase modulation element according to (3) above. (5) The plurality of divided regions include a first divided region, a second divided region, and a third divided region. The optical phase modulation element according to (1) above. (6) the first division region has a red region that displays a phase distribution pattern for red, the second division region has a green region that displays a phase distribution pattern for green, The third division region has a blue region that displays a phase distribution pattern for blue. The optical phase modulation element according to (5) above. (7) When the refractive index anisotropy of the liquid crystal material filled in the first divided region is ΔnR, the refractive index anisotropy of the liquid crystal material filled in the second divided region is ΔnG, and the refractive index anisotropy of the liquid crystal material filled in the third divided region is ΔnB, at the same wavelength, ΔnR ≥ ΔnG > ΔnB Fulfill The optical phase modulation element according to (6) above. (8) one of the plurality of divided regions has a blue region that displays a phase distribution pattern for blue; The divided area having the blue area has an area of ​​1 / 3 or more of the entire effective display area in the screen. The optical phase modulation element according to any one of (1) to (7) above. (9) A plurality of alignment films each made of a different material and provided corresponding to the plurality of divided regions; Further equipped The optical phase modulation element according to any one of (1) to (8) above. (10) one of the plurality of divided regions has a blue region that displays a phase distribution pattern for blue; Among the plurality of alignment films, the alignment film corresponding to the divided region having the blue region is made of an inorganic material. The optical phase modulation element according to (9) above. (11) Each of the plurality of divided regions has at least a part having a curved shape in an in-plane direction. The optical phase modulation element according to any one of (1) to (10) above. (12) A light source unit that emits a plurality of color lights having different wavelengths; an optical phase modulation element that phase-modulates each of the plurality of color lights from the light source unit; Including, The optical phase modulation element is a plurality of divided regions, the divided regions being provided in different regions in an in-plane direction, and filled with liquid crystal materials having different refractive index anisotropies, the divided regions each displaying a phase distribution pattern for a color having a different wavelength; Equipped Display device. (13) a light intensity modulation element that uses the reconstructed image generated by the optical phase modulation element as illumination light and generates an image by intensity-modulating the illumination light; Also includes The display device according to (12) above. (14) a projection optical system that projects an image generated by the light intensity modulation element; Also includes The display device according to (13) above.

[0210] This application claims priority based on Japanese Patent Application No. 2020-147720, filed on September 2, 2020 in the Japan Patent Office, the entire contents of which are incorporated herein by reference.

[0211] Those skilled in the art will recognize that various modifications, combinations, subcombinations, and variations may occur to those skilled in the art depending on design requirements and other factors, and that such modifications are within the scope of the appended claims and their equivalents.

Claims

1. a plurality of divided regions, the divided regions being provided in different regions in an in-plane direction, and filled with liquid crystal materials having different refractive index anisotropies, the divided regions each displaying a phase distribution pattern for a color having a different wavelength; Equipped Optical phase modulation element.

2. The plurality of divided regions include a first divided region and a second divided region.

2. The optical phase modulation element according to claim 1.

3. the first divided region has a red region displaying a phase distribution pattern for red and a green region displaying a phase distribution pattern for green, The second division region has a blue region for displaying a phase distribution pattern for blue.

3. The optical phase modulation element according to claim 2.

4. When the refractive index anisotropy of the liquid crystal material filled in the first divided region is ΔnR,G and the refractive index anisotropy of the liquid crystal material filled in the second divided region is ΔnB, at the same wavelength, ΔnR,G>ΔnB Fulfill 4. The optical phase modulation element according to claim 3.

5. The plurality of divided regions include a first divided region, a second divided region, and a third divided region.

2. The optical phase modulation element according to claim 1.

6. the first divided region has a red region displaying a phase distribution pattern for red, the second divided region has a green region that displays a phase distribution pattern for green, The third division region has a blue region for displaying a phase distribution pattern for blue.

6. The optical phase modulation element according to claim 5.

7. When the refractive index anisotropy of the liquid crystal material filled in the first divided region is ΔnR, the refractive index anisotropy of the liquid crystal material filled in the second divided region is ΔnG, and the refractive index anisotropy of the liquid crystal material filled in the third divided region is ΔnB, at the same wavelength, ΔnR≧ΔnG>ΔnB Fulfill 7. The optical phase modulation element according to claim 6.

8. one of the plurality of divided regions has a blue region that displays a phase distribution pattern for blue; The divided area having the blue area has an area of ​​1 / 3 or more of the entire effective display area in the plane.

2. The optical phase modulation element according to claim 1.

9. A plurality of alignment films each made of a different material and provided corresponding to the plurality of divided regions; Further equipped 2. The optical phase modulation element according to claim 1.

10. one of the plurality of divided regions has a blue region that displays a phase distribution pattern for blue; Among the plurality of alignment films, the alignment film corresponding to the divided region having the blue region is made of an inorganic material. The optical phase modulation element according to claim 9 .

11. Each of the plurality of divided regions has at least a part having a curved shape in an in-plane direction.

2. The optical phase modulation element according to claim 1.

12. A light source unit that emits a plurality of color lights having different wavelengths; an optical phase modulation element that phase-modulates each of the plurality of color lights from the light source unit; Including, The optical phase modulation element is a plurality of divided regions, the divided regions being provided in different regions in an in-plane direction, and filled with liquid crystal materials having different refractive index anisotropies, the divided regions each displaying a phase distribution pattern for a color having a different wavelength; Equipped Display device.

13. a light intensity modulation element that uses the reconstructed image generated by the optical phase modulation element as illumination light and generates an image by intensity-modulating the illumination light; Also includes The display device according to claim 12.

14. a projection optical system that projects an image generated by the light intensity modulation element; Also includes The display device according to claim 13.

Images