Light ray reproduction device, three-dimensional space display system, light ray reproduction method, and program

Abstract

A three-dimensional display device is provided with: a diffraction sheet (1) having a diagonal angle of 10 inches or more and having a diffraction layer including a first diffraction pattern arranged in a first array pattern and a second diffraction pattern arranged in a second array pattern on a transparent substrate; a liquid crystal device having a plurality of pixels; and a light source. In the normal direction of the diffraction sheet, the first diffraction pattern and the second diffraction pattern are disposed so as to overlap the pixels, and the amount of misalignment is 1 / 10 or less of the pitch of the pixels.

Description

[0001] This application is a divisional application of an application with the application number 202180050388.4, the application date of August 19, 2021, and the title “Diffractive sheet and manufacturing method thereof, three-dimensional display device, light ray reproduction device, three-dimensional space display system, light ray reproduction method, and program” and claims priority to Japanese Patent Application No. 2020-139079 filed in Japan on August 20, 2020, and Japanese Patent Application No. 2020-163317 filed in Japan on September 29, 2020, the contents of which are incorporated herein. TECHNICAL FIELD

[0002] The present application relates to a diffractive sheet and a manufacturing method thereof. It also relates to a three-dimensional display device, a light ray reproduction device, a three-dimensional space display system, a light ray reproduction method, and a program provided with the diffractive sheet.

[0003] This application is based on Japanese Patent Application No. 2020-139079 filed in Japan on August 20, 2020, and Japanese Patent Application No. 2020-163317 filed in Japan on September 29, 2020, which are hereby incorporated by reference herein in their entirety. BACKGROUND

[0004] It is known that various technologies for displaying a three-dimensional image (stereoscopic image) by controlling the direction of light using the diffraction phenomenon of light.

[0005] Patent Document 1 describes a three-dimensional image that naturally moves without image skipping by overlapping a light shielding mechanism such as a liquid crystal panel with a diffractive pattern.

[0006] In Patent Document 2 and Patent Document 3, a display body is described that displays a stereoscopic image with natural colors by configuring multiple diffractive elements such as a diffraction grating, a hologram, and the like, and combining a light source, a diffraction grating unit, and a color filter.

[0007] In this way, by aligning and combining a diffractive pattern in which multiple diffractive elements are arranged, and a pattern such as a liquid crystal or a color filter, it is possible to move a three-dimensional image or perform full-color display.

[0008] PRIOR ART DOCUMENTS

[0009] PATENT DOCUMENTS

[0010] Patent Document 1: Japanese Patent Application Publication No. H7-287192

[0011] Patent Document 2: Japanese Patent Application Publication No. H8-211821

[0012] Patent Document 3: Japanese Patent Application Publication No. 2017-219824

[0013] Patent Document 4: Japanese Patent Application Publication No. 2003-316241 SUMMARY

[0014] PROBLEMS TO BE SOLVED BY THE INVENTION

[0015] There is a demand to display a larger three-dimensional image using the above-described technology. However, a diffraction pattern that diffracts visible light is a minute structure of a submicron order, and is produced using an electron beam drawing device, a laser beam drawing device, or the like, and thus, in the current situation, the upper limit of the size that can be formed at one time is 10 inches (diagonal of a rectangle) or less.

[0016] As a method of producing a large-area diffraction pattern, a method of producing using a multi-faceted original composed of a plurality of unit originals is described in Patent Literature 4.

[0017] In the multi-faceted original, there is a limit to the accuracy when the plurality of unit originals are arranged, and misalignment of several tens of μm to several hundred μm occurs regardless. Even in the case where the transfer of the unit original is repeated a plurality of times while changing the position, the same misalignment cannot be avoided.

[0018] If only a three-dimensional image is displayed, the misalignment can be allowed, but in order to move the three-dimensional image or perform full-color display, the alignment of the diffraction pattern and the arrangement pattern of the color filter and the liquid crystal pixels is required. From the viewpoint of performing good display, it is required to converge the misalignment to 1 / 10 or less of the arrangement pitch, but due to the above-described situation, it is extremely difficult and almost impossible to achieve by the method described in Patent Literature 4.

[0019] Furthermore, in the related art, in a three-dimensional display device capable of displaying a moving three-dimensional image, a color three-dimensional image, in the case where a space having depth, in which an appropriate interpersonal distance (personal space) can be obtained, is displayed, there is a problem that sometimes a large blur occurs due to the influence of diffraction.

[0020] In view of the above-described situation, an object of the present application is to provide a diffraction sheet in which a diffraction pattern of high-precision arrangement can be achieved even in a large area.

[0021] Another object of the present application is to provide a large-area three-dimensional display device capable of displaying a moving three-dimensional image, a color three-dimensional image, and a light ray reproduction device, a three-dimensional space display system, a light ray reproduction method, and a program capable of displaying a three-dimensional space in which a natural sense of distance can be obtained and blur is small in the case where a space having depth is displayed.

[0022] Means for solving the problem

[0023] The three-dimensional display device of the first mode of the present application includes a diffraction sheet of 10 inches or more in diagonal, having a transparent substrate and a diffraction layer including a first diffraction pattern arranged in a first arrangement pattern on the substrate and a second diffraction pattern arranged in a second arrangement pattern, and either a liquid crystal device having a plurality of pixels or a color filter having two or more color filters.

[0024] In the three-dimensional display device, in a normal line direction of the diffraction sheet, the first diffraction pattern and the second diffraction pattern are arranged in overlap with the pixels or the color filters, and the misalignment amount is 1 / 10 or less of the pitch of the pixels or the color filters.

[0025] The manufacturing method of the diffraction sheet of the second aspect of the present application includes: a step A of forming a first uncured resin layer on a transparent substrate of 10 inches or more in diagonal; a step B of bringing a first diffraction pattern formed on one face of the first version in a rectangular range of 10 inches or more in diagonal to contact the first uncured resin layer; a step C of arranging a first mask having a plurality of first openings formed based on a first arrangement pattern on the first version, and irradiating light to cure the portion of the first uncured resin layer overlapping the first openings; a step D of forming a second uncured resin layer on the side of the substrate on which the first uncured resin layer is formed; a step E of bringing a second diffraction pattern different from the first diffraction pattern formed on one face of the second version in a rectangular range of 10 inches or more in diagonal to contact the second uncured resin layer; and a step F of arranging a second mask having a plurality of second openings formed based on a second arrangement pattern different from the first arrangement pattern on the second version, and irradiating light to cure the portion of the second uncured resin layer overlapping the second openings.

[0026] The diffraction sheet of the third aspect of the present application includes: a transparent substrate; and a diffraction layer including a first diffraction pattern arranged on the substrate in a first arrangement pattern, and a second diffraction pattern arranged on the substrate and on the same side as the first diffraction pattern in a second arrangement pattern different from the first arrangement pattern, the second diffraction pattern being thicker than the first diffraction pattern.

[0027] The light ray reproducing device of the fourth aspect of the present application is a device that reproduces light rays virtually emitted from a stereoscopic image in a case where the stereoscopic image is displayed in a reproduction space, and includes a stereoscopic image display unit that displays the stereoscopic image as at least either of a virtual image or a real image by light rays emitted from each element unit included in an element unit set composed of a plurality of element units two-dimensionally arranged in correspondence with a reproduction screen, and displays the stereoscopic image in a region in a depth direction in the reproduction space corresponding to a social distance, and the size of each element in the element unit set, and the pitch of the element units when the element units are two-dimensionally arranged, are values determined in accordance with the degree of observation of the stereoscopic image displayed in the reproduction space by an observer. In addition, the degree of observation by the observer described here indicates the position, range, degree of blurring allowed by the observer, and the like, of the stereoscopic image displayed.

[0028] According to the above light ray reproducing apparatus, it is possible to display a social distance space as a three-dimensional space in which a natural sense of distance is obtained and blurring is less.

[0029] Effects of the Invention

[0030] According to the above-described aspect of the present application, a diffraction pattern of high precision arrangement can be realized even for a large area.

[0031] Thus, it is possible to contribute to realization of a large-area three-dimensional display device capable of displaying a three-dimensional image of motion and a three-dimensional image of color, and a light ray reproducing apparatus, a three-dimensional space display system, a light ray reproducing method, and a program capable of displaying a three-dimensional space in which a natural sense of distance is obtained and blurring is less when a space having depth is displayed. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a view showing one process of a manufacturing method of a diffraction sheet according to the first embodiment of the present application.

[0033] Figure 2 is a view showing one process of the manufacturing method.

[0034] Figure 3 is a view showing one process of the manufacturing method.

[0035] Figure 4 is a view showing one process of the manufacturing method.

[0036] Figure 5 is a view showing one process of the manufacturing method.

[0037] Figure 6 is a view showing one process of the manufacturing method.

[0038] Figure 7 is a view showing one process of the manufacturing method.

[0039] Figure 8 is a view showing one process of the manufacturing method.

[0040] Figure 9 is a view showing one process of the manufacturing method.

[0041] Figure 10 is a view showing one process of the manufacturing method.

[0042] Figure 11 is a view showing one process of the manufacturing method.

[0043] Figure 12 is a view showing the completed diffraction sheet.

[0044] Figure 13is a view showing a modification of the diffraction sheet.

[0045] Figure 14 is a view showing a modification of the diffraction sheet.

[0046] Figure 15 is a view showing a diffraction sheet of the second embodiment of the present application.

[0047] Figure 16 is a view showing a three-dimensional display device of the present application.

[0048] Figure 17 is a view showing another example of a three-dimensional display device of the present application.

[0049] Figure 18 is a block diagram showing the configuration of a three-dimensional space display system of the third embodiment.

[0050] Figure 19 is a view showing an example of applying the three-dimensional space display system of the third embodiment.

[0051] Figure 20 is a block diagram showing the configuration of a three-dimensional space display system of the fourth embodiment.

[0052] Figure 21 is a view showing an example of applying the three-dimensional space display system of the fourth embodiment.

[0053] Figure 22 is a characteristic view showing the relationship between the distance from a three-dimensional display display to an object as an observation object and the size of blur generated when the object is reproduced.

[0054] Figure 23 is a characteristic view showing the relationship between the distance from a three-dimensional display display to an object as an observation object and the resolution (diffusion circle diameter) on the retina of an observer who observes the reproduced object.

[0055] Figure 24 is a view showing an example of the relationship between the size d and the pitch p in the element unit.

[0056] Figure 25 is a view showing an example of the case where a point object is reproduced as an object point A'.

[0057] Figure 26 is a view showing one example of the brightness distribution of light rays (reproduced light) reproduced from the element unit.

[0058] Figure 27 is a view showing an example of the case where a point object is reproduced as an object point A".

[0059] Figure 28It means through Figure 27 The diagram shows an example of a method that reproduces multiple objects.

[0060] Figure 29 This diagram illustrates the method of calculating data for reconstructing a hologram using ray tracing.

[0061] Figure 30 This is a schematic diagram illustrating the shape of the reproduced point as observed by an observer through the screen.

[0062] Figure 31 It is a schematic diagram showing that the light reproduced from the display becomes an expanded light and a blurred shape that becomes the reproduction point.

[0063] Figure 32 This is a schematic diagram used in the instruction manual to illustrate the expansion angle and size of Fraunhofer diffraction based on a circular opening.

[0064] Figure 33 This is a flowchart illustrating the processing flow performed by the three-dimensional display of the implementation method.

[0065] Figure 34 This is a block diagram illustrating the configuration of a three-dimensional spatial display system as a variation of the implementation method.

[0066] Figure 35 This is a diagram illustrating an example of a three-dimensional spatial display system that applies a variation of the implementation method.

[0067] Figure 36 This is a cross-sectional view illustrating the configuration of a conventional light field display using a microlens array.

[0068] Figure 37 This is a schematic cross-sectional view showing the configuration of a conventional static display type light field display made by overlapping liquid crystal panels. Detailed Implementation

[0069] <Diffraction Plate>

[0070] The following is for reference Figures 1 to 14 The diffraction plate of the first embodiment of the present invention will be described.

[0071] First, the manufacturing method of the diffraction plate 1 in this embodiment will be described.

[0072] As step A, such as Figure 1 As shown, an uncured resin layer (first uncured resin layer) 20 is formed on a transparent substrate 10 by layering photocurable resin. Glass and various resins can be used as the substrate 10. A typical example of a photocurable resin is an ultraviolet-curable resin, but other materials can also be used.

[0073] As Step B, as shown in Figure 2 the first diffraction pattern 100a formed in the first master 100 is brought into contact with the uncured resin layer 20.

[0074] The first master 100 is a large-area transparent master exceeding 10 inches in diagonal, and can be produced using the technology described in Patent Document 4. For example, when unit masters of 10 inches in diagonal are arranged in 3 x 3 or transferred in a two-dimensional matrix shape, a first master 100 of 30 inches in diagonal or so can be produced. The first diffraction pattern 100a is formed in a rectangular range of 10 inches in diagonal or more in one face of the first master 100. The range of formation of the first diffraction pattern 100a has substantially the same size as the diffraction sheet to be produced. The first diffraction pattern 100a has a surface shape corresponding to the diffraction pattern targeted. The surface of the first diffraction pattern 100a can also have a concave-convex shape, for example, having a plurality of convex portions protruding from the substrate of the first master 100.

[0075] In the following Step C, as shown in Figure 3 the first mask 110 is disposed on the first master 100, and light that cures the uncured resin layer 20 is irradiated.

[0076] The first mask 110 has a plurality of openings (first openings) 110a formed based on a first arrangement pattern. The first arrangement pattern is, for example, an arrangement of red filters of RGB color filters. The first mask 110 is substantially the same as a mask used for forming color filters, and can be produced comparatively easily by a known method even if it is a large-area mask.

[0077] By Step C, only the portion of the uncured resin layer 20 that overlaps the opening 110a in plan view and protrudes into the opening 110a is cured. Hereinafter, the uncured resin layer that is cured locally will be referred to simply as a "resin layer".

[0078] When the first master 100 and the first mask 110 are moved, and the uncured uncured resin in the resin layer 20 is removed by washing or the like, as shown in Figure 4 the first diffraction pattern 21 drawn as the first arrangement pattern is formed on the substrate 10. The first diffraction pattern 21 is formed of cured resin, and is formed in the same pattern as the opening 110a in plan view. In addition, a convex portion (surface concave-convex) based on the first diffraction pattern 100a is formed on the upper surface side (the side opposite the substrate 10) of the first diffraction pattern 21. In the first diffraction pattern 21, the portion in contact with the substrate 10 and the convex portion formed on the upper surface side can also be formed integrally by the same kind of resin.

[0079] In addition, the opening in the present specification refers to a portion where light is transmitted. Therefore, it is not necessary to have a hole (space) in the mask.

[0080] In the following Step D, a photocurable resin is arranged on the side of the substrate 10 where the first diffraction pattern 21 is formed, and an uncured resin layer (second uncured resin layer) 20A is formed as shown in Figure 5 The photocurable resin constituting the uncured resin layer 20A can be the same as or different from the resin used in Step A. The uncured resin layer 20A can also cover a part or all of the first diffraction pattern 21.

[0081] In the following Step E, the second plate 200 is caused to approach the uncured resin layer 20A so that the second diffraction pattern 200a formed in the second plate 200 contacts the uncured resin layer 20A, as shown in Figure 6

[0082] The second plate 200 is a transparent plate having the same size as the first plate 100. The second diffraction pattern 200a is a diffraction pattern different from the first diffraction pattern 100a, and is formed in a rectangular range of 10 inches or more on a diagonal in one face of the second plate 200.

[0083] In the following Step F, the second mask 210 is arranged on the second plate 200, and light for curing the uncured resin layer 20A is irradiated, as shown in Figure 7

[0084] The second mask 210 has a plurality of openings (second openings) 210a formed on the basis of a second arrangement pattern different from the first arrangement pattern. The second arrangement pattern is, for example, an arrangement of green filters of RGB color filters.

[0085] By Step F, only the portion of the uncured resin layer 20A that overlaps the opening 210a in plan view and protrudes into the opening 210a is cured. When the second plate 200 and the second mask 210 are moved, and the uncured uncured resin in the resin layer 20A is removed by washing or the like, a second diffraction pattern 22 drawn as the second arrangement pattern is formed on the substrate 10, as shown in Figure 8 At this time, the uncured resin covering a part or all of the first diffraction pattern 21 is also removed. The second diffraction pattern 22 is formed of cured resin, and is formed in the same pattern as the opening 210a in plan view. In addition, a convex portion based on the second diffraction pattern 200a is formed on the upper face side of the second diffraction pattern 22. In the second diffraction pattern 22, the portion in contact with the substrate 10 and the convex portion formed on the upper face side can also be integrally formed of the same kind of resin.

[0086] ​​In the next step G, a photocurable resin is disposed on the side of the substrate 10 where the second diffraction pattern 22 is formed, and as shown in the figure. Figure 9 As shown, an uncured resin layer (third uncured resin layer) 20B is formed. The photocurable resin constituting the uncured resin layer 20B can be the same as or different from any of the resins used in steps A and D. The uncured resin layer 20B can also cover part or all of the first diffraction pattern 21 and the second diffraction pattern 22.

[0087] As for the next step H, such as Figure 10 As shown, the third version 300 is brought close to the uncured resin layer 20B, so that the third diffraction pattern 300a formed on the third version 300 comes into contact with the uncured resin layer 20B.

[0088] The third version 300 is a transparent plate of the same size as the first version 100 and the second version 200. The third diffraction pattern 300a is a diffraction pattern that is different from either the first diffraction pattern 100a or the second diffraction pattern 200a, and is formed in a rectangular area of ​​more than 10 inches diagonally on one side of the third version 300.

[0089] In the next step I, as Figure 11 As shown, the third mask 310 is placed on the third version 300 and irradiated with light that cures the uncured resin layer 20B.

[0090] The third mask 310 has multiple openings (third openings) 310a formed based on a third arrangement pattern that is different from both the first and second arrangement patterns. The third arrangement pattern is, for example, the arrangement of the blue filter of an RGB color filter.

[0091] In step I, the portion of the uncured resin layer 20B that overlaps with the opening 310a only when viewed from above and is exposed into the opening 310a is cured. When the third version 300 and the third mask 310 are moved, and the uncured resin in the resin layer 20B is removed by cleaning or the like, as... Figure 12 As shown, a third diffraction pattern 23, which is drawn as a third arrangement pattern, is formed on the substrate 10. The third diffraction pattern 23 is formed by cured resin and forms the same pattern as the opening 310a when viewed from above. In addition, a protrusion based on the third diffraction pattern 300a is formed on the upper surface side of the third diffraction pattern 23. In the third diffraction pattern 23, the portion in contact with the substrate 10 and the protrusion formed on the upper surface side can also be integrally formed from the same type of resin.

[0092] Through the above processes, the diffraction plate 1 of this embodiment is manufactured. For example... Figure 12As shown, the diffraction sheet 1 is configured to have the diffraction layer 30 including the first diffraction pattern 21, the second diffraction pattern 22, and the third diffraction pattern 23 on the substrate 10.

[0093] The first diffraction pattern 21, the second diffraction pattern 22, and the third diffraction pattern 23 are respectively configured with high precision based on the first arrangement pattern, the second arrangement pattern, and the third arrangement pattern in plan view of the diffraction sheet 1. Therefore, by mounting in alignment in a color filter in which a color filter of three colors is arranged based on the first arrangement pattern, the second arrangement pattern, and the third arrangement pattern, or in a liquid crystal device in which pixels of the same size as the openings 110a, 210a, and 310a are arranged and which has a liquid crystal layer and a driving substrate, it is possible to align each of the diffraction patterns 21, 22, and 23 with the color filter and the pixels in the normal direction of the diffraction sheet 1 and to suppress the misalignment to 1 / 10 or less of the pitch of the color filter and the pixels.

[0094] According to the manufacturing method of the diffraction sheet of the present embodiment, the entire surface of each of the masks (the first mask 110, the second mask 210, and the third mask 310) used in steps C, F, and I is irradiated with light, and the uncured resin layer 20, 20A, 20B is cured, whereby the diffraction patterns 100a, 200a, and 300a formed on the surfaces of the respective masks (the first mask 100, the second mask 200, and the third mask 300) are transferred to the plurality of diffraction patterns 21, 22, and 23 on the upper surface side. Figure 1

[0095] Accordingly, even in a large area of 10 inches or more in diagonal, it is possible to form a diffraction layer 30 including a plurality of diffraction patterns while achieving high drawing precision.

[0096] In the present embodiment, an example in which formation of diffraction patterns using three sets of masks and masks is performed is described, but this is merely one example. The number of times of formation of diffraction patterns can be set to a desired number of two or more. That is, the diffraction sheet 1 can have only two kinds of diffraction patterns 21 and 22. The diffraction sheet 1 can be aligned with either a liquid crystal device having a plurality of pixels or a color filter having two or more color filters. At this time, when the first diffraction pattern 21 and the second diffraction pattern 22 are arranged to overlap the above-described pixels or the above-described color filters in the normal direction of the diffraction sheet 1, it is possible to suppress the misalignment to 1 / 10 or less of the pitch of the color filter and the pixels.

[0097] ​Thus, for example, by forming a plurality of patterns of the reproduced three-dimensional image slightly different each time, and mounting the liquid crystal device, a display device can be configured, and thus a moving three-dimensional image can be displayed.

[0098] Figure 13 The diffractive sheet 1A of the modification shown has the color filter 40 including a plurality of color filters between the substrate 10 and the diffractive layer 30. The diffractive sheet 1A is manufactured by forming the color filter 40 including a plurality of color filters on the substrate 10 using the first mask 110, the second mask 210, and the third mask 310, and then forming the diffractive layer 30 on the color filter 40.

[0099] In the manufacturing of the diffractive sheet 1A, the mask used when forming each color filter of the color filter 40 can be directly used as the first mask 110, the second mask 210, and the third mask 310, and thus the misalignment amount of each diffractive pattern and the corresponding color filter can be suppressed to 1 / 10 or less of the pitch of the color filters, and the manufacturing can be facilitated.

[0100] Figure 14 The diffractive sheet 1B of the modification shown has the diffractive layer 40A instead of the diffractive layer 30. The diffractive layer 40A has a first diffractive pattern 41 including a color material of red, a second diffractive pattern 42 including a color material of green, and a third diffractive pattern 43 including a color material of blue. That is, the diffractive layer 40A also functions as a color filter.

[0101] The diffractive sheet 1B can be manufactured by the same sequence as described above, only by mixing the corresponding color material in the material of the uncured resin layer. In the diffractive sheet 1B, there is an advantage that misalignment between the color filter and the diffractive pattern does not occur at all.

[0102] As explained above, the manufacturing method of the diffraction sheet 1, 1A, 1B of the present embodiment has: a step A of forming the first uncured resin layer 20 on the transparent substrate 10 of 10 inches or more in diagonal; a step B of bringing the first diffraction pattern 100a formed on one face of the first edition 100 over a rectangular range of 10 inches or more in diagonal into contact with the first uncured resin layer 20; a step C of disposing the first mask 110 having a plurality of first openings 110a formed based on the first arrangement pattern on the first edition 100, irradiating light to cure the portion of the first uncured resin layer 20 overlapping the first openings 110a; a step D of forming the second uncured resin layer 20A on the side of the substrate 10 on which the first uncured resin layer 20 is formed; a step E of bringing the second diffraction pattern 200a formed on one face of the second edition 200 over a rectangular range of 10 inches or more in diagonal, which is different from the first diffraction pattern 100a, into contact with the second uncured resin layer 20A; and a step F of disposing the second mask 210 having a plurality of second openings 210a formed based on the second arrangement pattern different from the first arrangement pattern on the second edition 200, irradiating light to cure the portion of the second uncured resin layer 20A overlapping the second openings 210a.

[0103] Thus, even with a large area of 10 inches or more in diagonal, high drawing accuracy can be achieved and a diffraction layer 30, 40A including a plurality of diffraction patterns can be formed.

[0104] Further, the diffraction sheet 1A of the present embodiment has: a transparent substrate 10; and a diffraction layer 30 including a first diffraction pattern 21 disposed on the substrate 10 in a first arrangement pattern, and a second diffraction pattern 22 disposed on the substrate 10 on the same side as the first diffraction pattern 21 in a second arrangement pattern different from the first arrangement pattern, and further has a color filter 40 disposed between the first diffraction pattern 21 and the second diffraction pattern 22 and the substrate 10 and including a plurality of color filters, and the misalignment of the first diffraction pattern 21 and the second diffraction pattern 22 with the color filters described above can be 1 / 10 or less of the pitch of the color filters when viewed from above.

[0105] In this configuration, the misalignment amount of each diffraction pattern 21, 22 and the corresponding color filter can be suppressed. Further, the mask used when forming each color filter of the color filter 40 can be directly used as the mask for making the diffraction patterns 21, 22, so that the manufacturing can be facilitated.

[0106] Further, it can be that the first diffraction pattern 41 and the second diffraction pattern 42 contain a color material, and the diffraction layer 40A functions as a color filter. In this configuration, there is the advantage that misalignment of the color filter and the diffraction pattern does not occur at all.

[0107] Further, the diffraction sheet 1, 1A, 1B can also be rectangular in plan view shape with a diagonal of 10 inches or more. In the present embodiment, as described above, even in the diffraction layer 30, 40A including a plurality of diffraction patterns, a high drawing precision can be achieved even for a large area of 10 inches or more in diagonal.

[0108] Reference Figures 15 to 17 A diffraction sheet of a second embodiment of the present application will be described. In the following description, explanation will be omitted for components common to those already explained, using the same reference numerals.

[0109] Figure 15 is a schematic view showing a diffraction sheet 2 of the present embodiment. The diffraction sheet 2 is provided with a diffraction layer 30A instead of the diffraction layer 30.

[0110] The first diffraction pattern 21 of the three diffraction patterns constituting the diffraction layer 30A is the same as that of the first embodiment. The second diffraction pattern 22A is the same as the second diffraction pattern 22 in the pattern itself, but is formed thicker than the second diffraction pattern 22. The third diffraction pattern 23A is the same as the third diffraction pattern 23 in the pattern itself, and is formed thicker than the second diffraction pattern 22A.

[0111] The diffraction sheet 2 can be manufactured by substantially the same procedure as that of the first embodiment. The points of change with respect to the first embodiment are as described below.

[0112] • In Step E, the uncured resin layer 20A is formed thicker than the uncured resin layer 20.

[0113] • In Step F, the second plate 200 is stopped at a position higher than the first plate 100.

[0114] • In Step G, the uncured resin layer 20B is formed thicker than the uncured resin layer 20A.

[0115] • In Step H, the third plate 300 is stopped at a position higher than the second plate 200.

[0116] The number of times of formation of the diffraction patterns can also be a desired number of 2 or more. In the case where the number of types of diffraction patterns in the diffraction layer 30A is increased, it is sufficient that the newly formed uncured resin layer is formed thicker than the uncured resin layer immediately before formed.

[0117] The diffraction sheet 2 of the present embodiment and the manufacturing method thereof exert the same effects as those of the first embodiment.

[0118] Further, the newly formed diffraction patterns are formed thicker, so the plate in contact with the uncured resin layer is less likely to come into contact with the already formed diffraction patterns. As a result, deformation, damage, and the like of the already formed diffraction patterns can be appropriately suppressed.

[0119] In the present embodiment, the size of the step difference between the diffractive patterns (the height difference between the different kinds of diffractive patterns) h can be appropriately set, for example, to 100 nm or more and 10 μm or less. In Figure 15 In the example of FIG. 6, the size h of the step difference between the diffractive patterns is the height difference between the first diffractive pattern 21 and the second diffractive pattern 22A, the height difference between the second diffractive pattern 22A and the third diffractive pattern 23A, and the height difference between the first diffractive pattern 21 and the third diffractive pattern 23A.

[0120] When the step difference becomes too large, the light leakage that becomes stray light incident on the adjacent color filters, pixels can increase.

[0121] When the average pitch of the diffractive patterns is d, the wavelength of the light is λ, and the diffraction angle is θ, the following equation 1 holds.

[0122] Sin(θ) = λ / d... (1)

[0123] At this time, the width w of the light leakage of the diffractive sheet 2 in plan view can be calculated according to the following equation 2. By suppressing the value of w to be 1 / 10 or less of the pitch of the color filters, pixels, the influence of the stray light can be reduced to an extent that is not problematic.

[0124] w = h x tan(θ)... (2)

[0125] As another viewpoint, the size h of the step difference is preferably equal to or greater than the depth of the surface concave-convex formed on the upper surface side of the diffractive pattern formed later. In addition, the size h of the step difference is preferably equal to or greater than 1.5 times the depth of the surface concave-convex. That is, the size h of the step difference is preferably equal to or greater than the protrusion height of the diffractive pattern 100a, 200a, 300a, and is preferably equal to or greater than 1.5 times the protrusion height of the diffractive pattern 100a, 200a, 300a. In this way, when the plate is brought into contact with the thicker uncured resin layer, the plate is less likely to come into contact with the formed diffractive pattern, and the formed diffractive pattern is appropriately maintained.

[0126] As described above, the manufacturing method of the diffractive sheet 2 of the present embodiment is such that, in step D, the second uncured resin layer 20A is formed to be thicker than the first uncured resin layer 20.

[0127] In addition, the thickness difference between the second uncured resin layer 20A and the first uncured resin layer 20 can also be equal to or greater than the height of the second diffractive pattern 200a.

[0128] The diffraction sheet 2 of the present embodiment includes a transparent substrate 10, and a diffraction layer 30A including a first diffraction pattern 21 arranged on the substrate 10 in a first arrangement pattern, and a second diffraction pattern 22A arranged on the substrate 10 and on the same side as the first diffraction pattern 21 in a second arrangement pattern different from the first arrangement pattern, the second diffraction pattern 22A being thicker than the first diffraction pattern 21.

[0129] According to this configuration, deformation, damage, and the like of the diffraction pattern 21 at the time of manufacturing the diffraction pattern 22A can be appropriately suppressed.

[0130] In addition, the thickness difference between the second diffraction pattern 22A and the first diffraction pattern 21 can also be equal to or greater than the depth of the surface unevenness of the second diffraction pattern 22A. According to this configuration, when the plate is brought into contact with the thicker uncured resin layer, the plate is less likely to come into contact with the formed diffraction pattern, and the formed diffraction pattern is appropriately maintained.

[0131] In addition, the thickness difference between the second diffraction pattern 22A and the first diffraction pattern 21 can also be equal to or greater than 100 nm and equal to or less than 10 μm. According to this configuration, the influence of stray light can be reduced to an extent that is not problematic.

[0132] <Three-dimensional display device>

[0133] A three-dimensional display device using the diffraction sheet of the present application is described. Figure 16 A schematic view of a three-dimensional display device 51 in which the diffraction sheet 1 is arranged on the incident side of a liquid crystal device LC. That is, the diffraction sheet 1 is arranged between a light source and the liquid crystal device LC. Light emitted from the diffraction layer 30 has an angle closer to perpendicular with respect to the diffraction sheet 1 than light incident on the diffraction sheet 1 from a light source not shown, and thus by appropriately aligning the diffraction pattern of the diffraction sheet 1 with the pixels of the liquid crystal device LC, light can be accurately guided to the liquid crystal device LC, a color filter mounted on the liquid crystal device LC.

[0134] Figure 17 A schematic view of a three-dimensional display device 52 in which the diffraction sheet 1 is arranged on the emission side of a liquid crystal device LC. That is, the liquid crystal device LC is arranged between a light source and the diffraction sheet 1. Light incident on the liquid crystal device LC becomes light with a stronger directivity by passing through the diffraction sheet 1, and thus display with a higher contrast and excellent color development can be performed.

[0135] In either case of the three-dimensional display devices 51, 52, when the distance between the diffraction sheet 1 and the liquid crystal device LC, the color filter is 500 μm or less, the misalignment of the light generated between them can be suppressed, and thus is preferable. The diffraction sheet 1 and the liquid crystal device LC or the like are preferably arranged in close contact (i.e., a distance of zero). In this case, from the viewpoint of sufficiently exerting the diffraction effect, an air layer or a vacuum layer can also be slightly present between the diffraction pattern and the liquid crystal device LC.

[0136] In the case of bringing the diffraction sheet 1 and the liquid crystal device LC or the like in close contact via an adhesive or a bonding agent, it is necessary to make the refractive index of the resin of the diffraction pattern different from the refractive index of the adhesive or the bonding agent.

[0137] In addition, the diffraction sheet possessed by the three-dimensional display devices 51, 52 is not limited to the diffraction sheet 1, and can also be the diffraction sheets 1A, 1B, 2. In addition, the three-dimensional display devices 51, 52 can also be provided with a color filter having two or more color filters instead of the liquid crystal device LC.

[0138] As described above, the three-dimensional display devices 51, 52 of the present embodiment are provided with: a diffraction sheet 1, 1A, 1B, 2 of 10 inches or more in diagonal, having a transparent substrate 10 and a diffraction layer 30, 30A, 40A including a first diffraction pattern 21, 41 arranged in a first arrangement pattern on the substrate 10 and a second diffraction pattern 22, 22A, 42 arranged in a second arrangement pattern; either one of a liquid crystal device LC having a plurality of pixels and a color filter having two or more color filters; and a light source, in the normal direction of the diffraction sheet 1, 1A, 1B, 2, the first diffraction pattern 21, 41 and the second diffraction pattern 22, 22A, 42 are arranged in overlap with the pixels or the color filters, and the misalignment amount thereof is 1 / 10 or less of the pitch of the pixels or the color filters.

[0139] According to this configuration, in a large-area three-dimensional display device capable of displaying a moving three-dimensional image, a color three-dimensional image, good display can be performed.

[0140] In addition, the diffraction sheet 1, 1A, 1B, 2 can also be arranged between the light source and the liquid crystal device LC or the color filter. Thereby, by appropriately aligning the diffraction pattern of the diffraction sheet 1, 1A, 1B, 2 with the pixels of the liquid crystal device LC or the color filters of the color filter, light can be guided to the liquid crystal device LC, the color filter with high precision.

[0141] In addition, the liquid crystal device LC or the color filter can also be arranged between the light source and the diffraction sheet 1, 1A, 1B, 2. The light incident to the liquid crystal device LC becomes light with a stronger directivity by passing through the diffraction sheet 1, 1A, 1B, 2, and thus display with a higher contrast, excellent color development can be performed.

[0142] The above describes each embodiment of the present application with reference to the drawings, but the specific configuration is not limited to the embodiments, and includes modifications, combinations, and the like of configurations within the scope of the gist of the present application. The following describes several modifications, but these are not all, and modifications other than these can be made. These modifications can also be appropriately combined with two or more.

[0143] By appropriately setting the elastic modulus of the diffraction pattern, it is also possible to not provide a step between the diffraction patterns. In this case, it is possible to suppress breakage of the already formed diffraction pattern due to the stamper, and generation of transfer defects in the newly formed diffraction pattern due to uneven pressure. From this viewpoint, the elastic modulus (hardness) of the formed (i.e., after curing) diffraction pattern is preferably 0.5 MPa to 100 GPa, and more preferably 2500 MPa to 13 GPa at room temperature.

[0144] In the manufacturing method of the diffraction sheet, a release layer can be provided on the surface of the diffraction pattern 100a, 200a, 300a of each stamper 100, 200, 300 used. In this way, after curing of the uncured resin layer in steps C, F, I, and the like, the stamper can be easily peeled off, and the diffraction pattern can be appropriately formed.

[0145] As the material of the release layer, a material that easily lubricates, such as silicon, a fluorine-based resin, a high molecule having an alkyl group, a thermosetting resin that becomes brittle by heating, and the like can be exemplified.

[0146] In the latter case, after curing of the uncured resin layer by light irradiation, the stamper is heated to cure the release layer. Then, when the stamper is moved, the brittle release layer is peeled off from the stamper and remains on the diffraction pattern, whereby the stamper is easily peeled off from the diffraction pattern. Then, the peeled release layer is removed from the diffraction pattern by washing or the like. After manufacturing of the diffraction sheet, a new release layer is arranged on the stamper for the next manufacturing. The thickness of the release layer that is peeled off from the stamper by heating can be set to, for example, 10 nm or more and 1 μm or less.

[0147] A transparent material having a different refractive index from the resin forming the diffraction pattern can be arranged on the diffraction pattern, whereby the surface of the diffraction layer is made flat. In addition, an adhesive resin material (adhesive material) can be used as the transparent material, whereby the diffraction layer 30, 30A, 40A is directly bonded to the liquid crystal device LC, color filter, or the like.

[0148] In addition, a gas layer of air or the like or a vacuum layer can be arranged on the diffraction layer 30, 30A, 40A. By making the diffraction pattern adjacent to the gas layer of air or the like or the vacuum layer, it is possible to appropriately diffract the incident light.

[0149] The uncured resin layer can also be formed of a thermosetting resin. In this case, by heating only the regions corresponding to the arrangement patterns, each diffraction pattern can be formed. In this case, the plate can also be opaque, and by being formed of a metal such as nickel, durability can be improved.

[0150] In the above-described diffraction sheet 1, 1A, 1B, 2 of the present application, the plurality of diffraction patterns can also be arranged without gaps, or can be arranged with gaps (intervals) of a certain width. The width of the gaps can be made to have a minimum effect on display quality, as long as it is below the width of the barrier in a liquid crystal pixel, or the black matrix formed on a color filter, when viewed from above. In view of the general dimensions of the barrier and the black matrix, the width of the gaps is preferably 1 μm or more and 100 μm or less, and more preferably 5 μm or more and 40 μm or less.

[0151] <Three-dimensional space display system>

[0152] In the related art, in a three-dimensional display device capable of displaying a moving three-dimensional image, a color three-dimensional image, in a case where a space having depth capable of obtaining an appropriate interpersonal distance (personal space) is displayed, there is a problem that a large blur can sometimes occur due to the influence of diffraction. The present inventors have intensively studied a three-dimensional display device that, for example, using the above-described diffraction sheet 1, 1A, 1B, 2, is mainly capable of displaying a space having a depth of 1.2 m or more and 3.6 m or less (social distance space) or a space having a depth more than that, as a three-dimensional space in which a natural sense of distance is obtained and blur is less. This will be described in detail below.

[0153] In the world of family, close relationships, or politics and business, it is important to know each other's feelings in communication. In the non-verbal part, it is necessary to convey the rhythm of the conversation and the sense of distance of the personal space without any sense of incongruity, and it is also important to obtain non-verbal information such as the expressions and movements of the other person in this sense of distance.

[0154] Various technologies are provided as technologies for smoothly conducting communication. For example, in the field of communication technology, communication delay is reduced by the low delay technology of 5G, and the rhythm of the conversation can be obtained with the same feeling as an actual conversation even in an online conversation. In addition, the distance of a person can be accurately measured using a three-dimensional measurement technology such as TOF (Time of Flight). However, there is no technology for displaying a space having depth capable of obtaining an appropriate interpersonal distance (personal space) without any sense of incongruity.

[0155] Herein, the space having depth in the present application refers to a space of a larger size than a space in which an interpersonal distance of 1.2 m or more and 3.6 m or less is obtainable, which is mainly used when a person communicates with another person on business. In the following description, the space having depth in which an interpersonal distance of 1.2 m or more and 3.6 m or less is obtainable will be referred to as a "social distance space".

[0156] There are various techniques for displaying a three-dimensional image having depth. For example, there are techniques for displaying a stereoscopic image by wearing a display device such as a head-mounted display, a polarized glasses type, a liquid crystal shutter glasses type, or not wearing and making two eyes observe different parallaxes such as a parallax barrier type and a see-through display type. Such a technique for displaying a three-dimensional image perceives stereoscopic vision only by parallax. Therefore, convergence, focusing, and the like are required to make a line of sight converge on a point, and thus a person sometimes feels eye strain and dizziness. Therefore, as a tool for displaying a social distance space having depth, it is sometimes not appropriate.

[0157] In contrast to this, in Non-Patent Literature 1, a technique for displaying a three-dimensional image without performing convergence and focusing is disclosed.

[0158] Non-Patent Literature 1: [online], "Research Trends in Light Field Displays", March 2018, Takane Kikuchi, [Retrieved on August 3, 2020], Internet <URL: https: / / home.jeita.or.jp / device / lirec / symposium / fpd / pdf / 2018_2a.pdf>.

[0159] In Non-Patent Literature 1, a display (see Figure 36 ) is disclosed in which a light field (directional information and intensity distribution of light rays incident on a shooting surface of a digital camera on the shooting surface) is recorded using a super multi-eye display or a microlens array, and the recorded light field is reproduced (displayed). In addition, a light field display of a static display type in which a liquid crystal panel or the like is overlaid (see Figure 37 ) is proposed.

[0160] In addition, according to the stereoscopic image display device described in Patent Literature 5, a technique for making the number of viewpoints sufficiently large (super multi-eye) is disclosed.

[0161] Patent Literature 5: Japanese Patent Application Publication No. 2007-17634

[0162] According to the technology of Patent Literature 5, for human stereoscopic vision, four important factors of binocular parallax, focus adjustment, convergence, and motion parallax can be satisfied. In display of a three-dimensional image by such a super multi-eye display, a light field display, light rays are reproduced in a size smaller than the pupil size, and thus natural focus adjustment and convergence are realized.

[0163] However, the super multi-eye display and the like described in Patent Literature 5 reproduce light rays in a size smaller than the pupil size, and thus realize natural focus adjustment and convergence. Since light rays are controlled in a small area, blur becomes larger as the distance from the display surface increases due to the influence of diffraction. Therefore, only objects near the display can be reproduced, and in a case where the display surface is placed near the social distance space, it is difficult to realize reproduction of the social distance space. On the other hand, in a case where the display surface is placed near the social distance space by being distanced from the observer, the display needs to be a size larger than the space to be displayed, and needs a higher cost and a larger installation space.

[0164] As described above, in order to reproduce the social distance space, in the conventional light field display, there is a problem that a large blur occurs due to the influence of diffraction.

[0165] In view of the above problem, the inventors have researched a light ray reproduction device, a three-dimensional space display system, a light ray reproduction method, and a program, and mainly a space having a depth of 1.2 m or more and 3.6 m or less (a social distance space) or a space having a depth more than that can be displayed as a three-dimensional space in which a natural sense of distance is obtained and blur is less.

[0166] Hereinafter, a three-dimensional space display system of an embodiment of the present application will be described in detail with reference to the drawings. The three-dimensional space display system 1S is installed, for example, by an optical device and a circuit. In addition, the present application is not limited to the embodiment itself below, but can be embodied by an appropriate combination, modification, as long as the gist is not deviated.

[0167] Figure 18 is a block diagram showing the configuration of the three-dimensional space display system 1S of the third embodiment. The three-dimensional space display system 1S has, for example, a communication section CM, a stereoscopic camera SC, and a three-dimensional display 3D. The communication section CM communicates with the outside via a digital communication network NW.

[0168] The stereoscopic camera SC is a camera that stereoscopically photographs an object as an observation target, and is, for example, a stereo camera. The stereoscopic camera SC transmits three-dimensional information of the object as the observation target to the three-dimensional display 3D via the communication section CM. The three-dimensional information here includes at least the incident direction and intensity of light rays incident from the object to a photographing surface, and can be information obtained from a combination of two or more parallax image columns, a two-dimensional image, and a distance image, or the like, as long as it is information indicating a space including the object as the observation target.

[0169] As a method for acquiring three-dimensional information, various methods can be considered. For example, in the case where the stereoscopic camera SC is a stereo camera, there is a method of acquiring three-dimensional information by measuring depth information (hereinafter, also referred to as depth information, a depth distance, or the like) using images photographed by two cameras, respectively. Alternatively, there is a method of analyzing a pattern projected to a photographing target object. Further, there is a TOF method of measuring a distance to the object as the observation target by measuring a time of flight of light, or the like. The method for acquiring three-dimensional information can use any method as long as it can measure at least a range of the social distance with a resolution required. In particular, the TOF method is preferable in that it can measure a depth distance of several cm to several m with high accuracy.

[0170] The range of the space photographed by the stereoscopic camera SC is preferably a space large enough to recognize a social distance space. For example, a space expanded to a depth of 3.6 m with an angle of ±30 degrees is preferable as a space with an angle of view of 60 degrees or more. For example, when the angle of view is 80 degrees or more, which is equivalent to a wide-angle lens with a focal length of 25 mm, a space with a higher sense of reality can be photographed. Further, the minimum resolution Δα in the angle direction is preferably a resolution of 0.033 degrees or less, which is equivalent to a visual acuity of 0.5 degrees.

[0171] For example, in the case where the resolution of the stereoscopic camera SC is high definition (pixel number 1080 x 1920), the angle of view is set to 73 degrees or less in order to set the minimum resolution Δα in the angle direction to 0.033 degrees or less. Further, in the case where the resolution of the stereoscopic camera SC is 4K (pixel number 2160 x 3840), the minimum resolution Δα in the angle direction is set to 146 degrees or less. Thus, in the case where the social distance space is photographed with an angle of view of 80 degrees or more, it is preferable to photograph the space with the stereoscopic camera SC with a resolution of 4K or more.

[0172] The communication section CM performs communication of three-dimensional information with an external device using a digital communication network NW capable of stably transmitting a moving image of three-dimensional information. In order to stably transmit a moving image including an image of resolution 4K and depth information of each pixel, the communication speed is preferably 25 Mbps or more, for example. As the digital communication network, in the case of using a mobile communication network, communication with a remote information processing device becomes easy by using a standard of 5G or more, for example.

[0173] The three-dimensional display 3D is a computer device such as a PC (Personal Computer), a server device, or a cloud server that displays a three-dimensional image. The three-dimensional display 3D has, for example, an arithmetic section 31, a control section 32, a light source section 33, a display section 34, a light control section 35, and a storage section 36. Here, the three-dimensional display 3D is an example of a "ray reproduction device". The arithmetic section 31 is an example of a "signal processing section". The control section 32 is an example of a "signal processing section". The display section 34 is an example of a "stereoscopic image display section". The light control section 35 is an example of a "stereoscopic image display section".

[0174] The arithmetic section 31 and the control section 32 are functional sections (signal processors) that perform signal processing, which are realized by, for example, a CPU (Central Processing Unit) of the three-dimensional display 3D executing a program stored in advance in the storage section 36. Alternatively, the functional sections that perform these signal processes can be realized as an integrated circuit such as an ASIC (Application Specific Integrated Circuit).

[0175] The arithmetic section 31 calculates the components (directions and intensities of rays) of rays that should be reproduced (displayed) for each element unit on the basis of three-dimensional information acquired from the stereoscopic camera SC. The element unit here will be described in detail later.

[0176] The control section 32 controls the light source section 33, the display section 34, and the light control section 35 to reflect the directions and intensities of rays reproduced for each element unit. Thus, a space with a natural sense of distance and without blurring can be displayed. Alternatively, in the case where the light source section 33 and the light control section 35 in the three-dimensional display 3D are passive and do not need to be controlled, the functional sections (light source section 33 and light control section 35) do not need to be controlled by the control section 32.

[0177] In addition, in a case where the image is displayed using only the three-dimensional information obtained from the outside via the communication section CM without using the three-dimensional information obtained from the stereoscopic camera SC, the stereoscopic camera SC in the three-dimensional space display system 1S can be omitted. On the other hand, in a case where the image is displayed on the three-dimensional display display 3D using only the three-dimensional information from the stereoscopic camera SC, the communication section CM in the three-dimensional display display 3D can be omitted.

[0178] The light source section 33 has a light source function including a light emitter such as a laser, an LED (Light-Emitting Diode), an EL (Electro-Luminescence), and the like, and is a functional section that becomes a light source of the display section 34. The light control section 35 controls the direction and intensity of the light source irradiated by the light source section 33 according to a control signal from the control section 32.

[0179] The display section 34 has a display function using a display element such as an LCD (Liquid Crystal Display), an OLED (Organic LED), a DMD (Digital Mirror Device), and the like. The display section 34 displays an image according to the control of the control section 32.

[0180] As the display section 34, a display device that displays a two-dimensional image such as an LCD, an LED, an OLED, a DLP (Digital Light Processing), and the like is generally used. However, it is not limited thereto. The display section 34 can also be a type in which the light source section 33 such as a laser light source or an LED light source is scanned. In the case of a self-emission device such as an LED or an OLED, the display section 34 has both a light source function and a display function. The display section 34 can realize both the display function and the light control function by one device if it can control the direction of light by a diffraction pattern such as a hologram.

[0181] In addition, in the following description, the display surface 34a (refer to Figure 25 and the like) refers to a surface on which a pattern is displayed by the display device of the display section 34, and in a case where a plurality of display devices are used to display an image, refers to a surface closest to an observer.

[0182] The storage section 36 is constituted by a storage medium such as an HDD (Hard Disk Drive), a flash memory, an EEPROM (Electrically Erasable Programmable Read Only Memory), a RAM (Random Access read / write Memory), a ROM (Read Only Memory), or any combination of these storage media. The storage section 36 stores programs for executing various processes of the three-dimensional display display 3D and temporary data used when the various processes are performed. The storage section 36 stores, for example, three-dimensional information obtained by the stereo camera SC. The storage section 36 stores the operation results of the operation section 31. The storage section 36 stores information indicating the direction, intensity, and the like of light rays reproduced by the control of the control section 32.

[0183] Figure 19 is a diagram illustrating an example of the three-dimensional space display system IS to which the third embodiment is applied. Figure 19 The XY directions indicate the planar directions, and the Z direction indicates the vertical direction. The stereo camera SC is disposed so as to be able to take an image of the entity space JK that is an observation target. A plurality of entity images IM (entity images IM1 to IM7) are arranged in the entity space JK. The three-dimensional display display 3D is disposed so that the displayed image can be observed by the observer OB.

[0184] The stereo camera SC takes an image of the entity space JK. The three-dimensional display display 3D displays a reproduction space SK in which the entity space JK taken by the stereo camera SC is reproduced (displayed). In addition, in the example of Figure 19 In the example of

[0185] In the example of Figure 19In the example, the 3D spatial display system 1S functions as a 3D image display exchanger that enables communication between the recording (capturing) and reproduction (display) of 3D information with a time difference. That is, the 3D information of the physical space JK captured by the stereo camera SC is stored in the storage unit 36, and then, at any time desired by the observer OB, the desired 3D image is reproduced in the reproduction space SK. Thus, even if the observer OB is not present during the capture, the physical image IM of the physical space JK at the time of capture can be observed at any time after the capture.

[0186] Furthermore, while the examples of recording and reproducing with a time difference have been shown above, this is not a limitation. For instance, a stereoscopic camera SC and a 3D display can be positioned in separate locations such as a hallway and a living room, functioning as a 3D image communicator for communication in these isolated locations where direct visual observation is not possible. Thus, the observer OB can experience (observe) the physical space JK from a distance without moving there.

[0187] Here, we will describe in detail the social distance space that is the subject of this application. Social distance space is not the space displayed by a conventional three-dimensional display (stereoscopic image display device) where the object (subject) exists near the display. Social distance space is the space within the space displayed by the display, where the subject exists at a position separated along the depth direction. Social distance space can be, for example, the space inside a room, the space in a park, etc., a space where an observer (subject) exists within that space. It can also be the space displayed when the display is used as a window to observe the space outside (such as the space inside a room) from that window.

[0188] American cultural anthropologist Edward Hall categorized interpersonal distance (personal space) between people into the following four distance zones.

[0189] 1) Close contact distance

[0190] 2) Individual distance

[0191] 3) Social distancing

[0192] 4) Public Distance

[0193] 1) such as Figure 19 As shown, close proximity ID refers to a distance of 0 to 0.45 meters from another person, such as a distance close enough to perceive their body temperature or scent. Close proximity is the distance between people in a very intimate relationship, primarily involving skin contact such as holding hands and communication based on scent.

[0194] 2) Individual distance (PD) refers to a distance of 0.45 to 1.2 meters between oneself and another person. It is the distance one maintains in order to maintain independence from others. It is the distance at which one or the other person can reach out and touch, and it is the interpersonal distance when communicating with close people such as friends.

[0195] 3) Social distance (SD) refers to a distance of 1.2 to 3.6 meters between people, which is a distance that makes it difficult to touch the other person. It is the interpersonal distance suitable for formal occasions such as conversations between colleagues in the workplace.

[0196] 4) Public distance refers to a distance of 3.6m or more between two people, which is not suitable for communication, such as interpersonal distance in the context of giving speeches or lectures.

[0197] Figure 20 This is a block diagram illustrating the configuration of the three-dimensional spatial display system 100S according to the fourth embodiment. In the three-dimensional spatial display system 100S of this embodiment, multiple... Figure 18 The three-dimensional spatial display systems 1S (1S-2, 1S-2, etc.) shown are interconnected via a digital communication network NW. This constitutes multiple three-dimensional image display exchanges that can remotely and naturally communicate with each other. Furthermore, the three-dimensional information acquired by the stereo cameras SC (SC-1, SC-2, etc.) is compressed and / or converted as needed through signal processing by the arithmetic unit 31, etc., and then transmitted to the communication destination via the communication unit CM (CM-1, CM-2, etc.).

[0198] In addition, there are no particular restrictions on the communication means of the Communication Department CM, but since it is necessary to send and receive three-dimensional information, it is preferable to have a communication means that can transmit large amounts of information at high speed, such as the 5G communication network listed above.

[0199] Figure 21 This is a diagram illustrating an example of a three-dimensional spatial display system 100S using the fourth embodiment. Figure 21 The XY directions represent the planar direction, and the Z direction represents the vertical direction. The position, orientation, and number of stereo cameras (SC) are determined by... Figure 19 The same applies to 3D display monitors. In the example shown in the figure, the 3D spatial display system 100S functions as a 3D image display exchanger that enables natural communication between two remote locations connected via a digital communication network NW.

[0200] That is, three-dimensional information obtained by the stereoscopic camera SC-1 which photographs a person present in the real space JK-1 is transmitted to the three-dimensional display 3D-2 via the digital communication network NW. Thereby, a reproduced space SK-1 which reproduces the space (the real space JK-1) photographed by the stereoscopic camera SC-1 is displayed on the three-dimensional display 3D-2.

[0201] On the other hand, three-dimensional information obtained by the stereoscopic camera SC-2 which photographs a person (in this example, one person) present in the real space JK-2 is transmitted to the three-dimensional display 3D-1 via the digital communication network NW. Thereby, a reproduced space SK-2 which reproduces the space (the real space JK-2) photographed by the stereoscopic camera SC-2 is displayed on the three-dimensional display 3D-1.

[0202] Here, the following is used. Figure 22 An element unit of the present embodiment will be described. Figure 22 is a characteristic diagram which shows the relationship between the distance from the three-dimensional display 3D to the object which becomes the observation target and the size of the blur which occurs when the object is reproduced. Figure 22 The horizontal axis of Figure 22 indicates the distance from the display. The vertical axis of

[0203] indicates the size of the blur. Figure 30 Generally, in a display which can perform focusing, as shown in , the observer observes the space in front and behind of the display face 34a, and when the light rays in the same direction as the light rays which expand from the point object which should be reproduced, that is, the reproduced point, are reproduced in a size smaller than the pupil of the observer, the observer can observe as if there is a point light source in the space.

[0204] Figure 31 However, the light rays reproduced from the display become light having expansion due to various reasons as shown in , and this becomes an important factor which causes the blur of the reproduced image. In particular, in the case where the element unit of the display which determines the direction of the light rays is small, the light is bent to the outside of the opening, expands due to the influence of the diffraction which uses the element unit as the opening, and the blur occurs.

[0205] The expansion of the diffraction caused by the opening can be approximated as Fraunhofer diffraction at a position far from the display face 34a, and in the case of a circular opening, the expansion angle can be found from the size of the Airy disk (a brighter region which occurs in the center of the diffraction pattern). That is, for the interval between the smallest dark ring which is formed in the far field which is far from the circular opening and the optical axis, when the expansion angle θ of the light rays which are parallel to the optical axis and pass through the end face of the circular opening is expressed, it can be expressed as follows (refer to Figure 32 ). Here, λ in (Equation 3) is the wavelength of the light, and d is the diameter of the circular opening.

[0206] θ = 1.22 × λ / d……(Equation 3)

[0207] The opening described above becomes a unit of area on the display that defines the direction of light. This unit is called a "feature unit". Hereinafter, the feature unit will be described using the reference numeral C. A collection of multiple feature units C is called a feature unit set. Feature unit C is, for example, a light field display using a microlens array (…). Figure 36 In a light field display (e.g., a lens corresponds to element unit C), a lens is equivalent to element unit C. Additionally, in a static display type light field display with superimposed liquid crystal panels, etc.,... Figure 37 In the case of ), the pixels of the display used become the element unit C.

[0208] In a light field display, the direction of light is controlled according to each element unit C. Therefore, in order to have a focusing function, the element unit C needs to be sufficiently smaller than the observer's pupil. Generally, the size of a human pupil is around 2 to 8 mm. Therefore, when the size of the element unit C is set to 0.3 mm and the wavelength of light is set to 500 nm, the spread angle of the light is represented by (Equation 3) as follows.

[0209] θ = 1.22 × 500 × 10 -6 / 0.3

[0210] ≈2.03×10 -3 (rad)

[0211] ≈0.12(degree)

[0212] That is, in Figure 32 The blur produced by a ray of light passing through a 0.3mm element C located at a distance L = 3.6m from a surface with a circular opening is 3600 × tan(0.12°) × 2 ≈ 15 (mm), meaning it extends to a length of approximately 15mm. For example, when a 15mm blur is produced on the face of a person at a distance of 3.6m, although the person can be identified, their expression is difficult to read.

[0213] Generally, a person with 1.0 visual acuity has an uncorrected angular resolution of 1 / 60 degree. The element C, whose size d is equivalent to the diffraction-induced spread angle θ, can be represented by (Equation 3) as follows when the wavelength is set to 500 nm.

[0214] d = 1.22 × 500 × 10 -6 / tan(1 / 60°)×2

[0215] =4.2mm

[0216] Similarly, the resolution of the angle of 1 / 60 / 0.7 degrees, which is equivalent to the condition of 0.7 of the visual acuity of the driver's license, and the size of the blurring element unit C is 2.9 mm. The minimum visual acuity that does not require glasses is 0.3 of the visual acuity, and the size of the blurring element unit C calculated by the same calculation under this condition is 1.2 mm. Under the condition of 0.2 of the visual acuity, the size of the blurring element unit C is 0.8 mm. It can be said from this case that in order to suppress the blur that can be allowed at the time of observation, a size d of the element unit C of 0.8 mm or more is required at least.

[0217] Here, in Figure 22 , the size d of the element unit C is taken as a parameter, and the relationship between the distance L from the display and the size of the blur caused by diffraction is shown. The size d of the element unit C corresponds to d in Figure 32 . That is, the size d of the element unit C calculated in the above is equivalent to the size calculated as d = 4.2 mm, 2.9 mm, 1.2 mm, or 0.8 mm according to the condition.

[0218] As shown in Figure 22 , it is known that if the distance (L) from the display is the same, the larger the size (d) of the element unit C, the smaller the size of the blur. This is reflected in (Formula 3) as the larger the d, the smaller the spread angle θ.

[0219] Here, the interval (pitch p) at which the element unit C is arranged is described using Figure 23 . Figure 23 is a characteristic diagram showing the relationship between the distance (object distance) from the three-dimensional display 3D to the object as an observation object and the resolution (diffusion circle diameter) on the retina of the observer who observes the reproduced object. Figure 23 The horizontal axis of Figure 23 indicates the distance from the display. The vertical axis of

[0220] indicates the diffusion circle diameter.

[0221] As shown in Figure 23As shown, it is understood that if the distance (L) from the observer to the object is the same, the smaller the pitch (p) of the element units C, the smaller the diameter of the blur circle. The interval of the visual cells on the human retina is about 10 μm (0.01 mm), and thus it is understood that in order to have good resolution (smaller blur circle diameter), if it is an object farther than 1.2 m away, the pitch p of the element units C needs to be about 0.4 mm or less.

[0222] Further, it is understood that if it is a use that allows a resolution (blur circle diameter on the retina of about 30 μm (0.03 mm) degree) of a display of the order of 24 inches of XGA (Extended Graphics Array: standard published by IBM Corporation in 1990) in a distance of 0.5 m away, if it is an object farther than 1.2 m away, the pitch p of the element units C can be configured to be 1.2 mm or less.

[0223] Summarizing the above, if communication is performed in a social distance SD (distance range of about 1.2 m to 3.6 m from the display), as long as the size d of the element units C is 0.8 mm or more and the pitch p of the element units C is 1.2 mm or less, communication that is not practically obstructed can be achieved.

[0224] Further, Figure 23 The horizontal axis is the distance from the observer to the object, but the distance at which the observer observes the display surface 34a of the device is not known at the time of design. Thus, at the time of design, the case in which the observer is closest to the display surface 34a is assumed, and the distance from the observer to the object is calculated as the distance from the display surface 34a to the object.

[0225] Figure 24 is a schematic diagram in the case in which the pitch p of the element units C is greater than the size d of the element units C (p > d). This is one example in which the size d of the element units C is 0.8 mm or more and the pitch p of the element units C is 1.2 mm or less as described above. In this case, since p > d, the element units C do not overlap each other. Thus, the diffraction grating pattern (diffraction pattern) also does not overlap and is independent.

[0226] Figure 25 is a conceptual diagram in the case in which a point object is reproduced as a point object A' by the display of the present application. Each element unit C reproduces the direction of light (virtual light L') emitted from the point object A' in the display surface 34a. When viewed from various directions from above the drawing (i.e., when the display surface 34a is viewed from various directions from the observer OB side), the observer OB can observe as if there is a point object A' in each direction.

[0227] In the present embodiment, as inFigure 23 As explained in Figure 22 , it is assumed that the pitch p of the element unit C is sufficiently small relative to the size of the pupil. In addition, as explained in , it is assumed that the size d of the element unit C is a size in which blurring due to diffraction is less. Thus, the conditions required for stereoscopic display such as convergence, focusing, binocular disparity, etc. are reproduced to the observer OB without contradiction. Thereby, the observer OB does not feel eye fatigue. That is, even in a space away from the display surface 34a, a natural and non-contradictory space can be reproduced.

[0228] On the other hand, as shown in Figure 25 , the light ray (reproduced light L) emitted from each element unit C has a width of the size (d) of the element unit C + the spread (Δα) due to diffraction. Thus, there is no problem in the case of observing a space away from the display surface 34a, but in the case of observing an object close to the display surface 34a, the resolution of the object is reduced.

[0229] As a countermeasure therefor, several methods can be considered. For example, as shown in Figure 26 , it is possible to consider making the distribution of the brightness of the light ray reproduced from the element unit C a characteristic distribution. Figure 26 is a graph showing one example of the distribution of the brightness of the light ray (reproduced light L) reproduced from the element unit C. Figure 26 The upper side of Figure 26 is a schematic view showing an image of the distribution of the brightness of the reproduced light L emitted from the element unit C.

[0230] As shown in Figure 26 , the brightness of the light ray reproduced from the element unit C is made a distribution in which the center is brighter and becomes darker as it goes from the center toward the periphery. Thereby, it is possible to increase the resolution of the reproduced object. In order to produce such a distribution of the brightness of the light ray, it is realized by providing a change in diffraction efficiency within the element unit C in such a way that the transmittance of the interference fringe pattern recorded in the element unit C decreases as it goes from the center portion toward the peripheral portion.

[0231] In addition, as a method of preventing resolution reduction, as shown in Figure 27 , it is possible to consider adjusting the size of the object point "A" produced by the light ray of the reproduced light L reproduced from each element unit C. That is, as the element unit C, an element unit C in which the interference fringe of the wavefront from the object point produced by the virtual light L" diffused from the object point A" and the reference light is recorded on the display surface 34a is formed. Thereby, as shown in Figure 27As shown, the size of the object point A" generated by the light rays reproduced from each elemental unit C can be reduced to the diffraction limit of the size d of the elemental unit C.

[0232] As a method to realize this, there is, for example, a method of using a CGH (Computer-Generated Hologram) calculated for each elemental unit C. In this method, a hologram of a wave surface at the time when light from an object (virtual light L") reaches the position of an elemental unit C is calculated. In this method, the operation for each elemental unit C is performed. Therefore, a high-speed operation that is less in the amount of operation compared to the calculation of a general CGH and that can also perform parallel operation as described later can be performed.

[0233] In this case, even if only one elemental unit C, the function of focusing can be satisfied. Therefore, even if the pitch p of the elemental unit C is 1.2 mm or more, a natural stereoscopic display can be realized. However, in order to smoothly change an image as the viewpoint of the observer OB moves, the pitch p of the elemental unit C is preferably the size of the pupil or less. Therefore, the pitch p of the elemental unit C is at least 7 mm or less, and is preferably 2 mm or less. That is, in the case where the elemental unit C is a hologram in which a spherical wave from an object is recorded, by setting the size d of the elemental unit C to 1.2 mm or more (corresponding to visual acuity of 0.5) and the pitch p of the elemental unit C to 2 mm or less, a stereoscopic image of higher resolution can be observed.

[0234] Using Figure 28 The method of reproducing a plurality of objects by Figure 27 The configuration in the case where a plurality of objects are reproduced by the method will be described. In each elemental unit C of the display surface 34a, an interference fringe of a spherical wave diffused from each point on the surface of an object and a reference light is recorded. From an object B' existing at a position closer to the display surface 34a, a spherical wave diffused from a closer point is reproduced. On the other hand, from an object C' existing at a position farther from the display surface 34a, a spherical wave diffused from a farther point is reproduced. In this way, the wave surface is recorded differently depending on the distance from the display surface 34a to the object.

[0235] In the present embodiment, the interference fringe of a spherical wave diffused from each point on the surface of an object and a reference light is digitized by the stereoscopic camera SC. This is the same as a conventional digital hologram, but in the present embodiment, it is characterized in that the object is sampled. That is, as shown in FIG. 6, a point at which the object is sampled is set to a point resolved at an angle of Δα from each elemental unit position. Figure 29

[0236] ​Thus, in the conventional digital hologram, the wavefront is calculated with a sampling pitch of the order of μm, whereas in the method of the present embodiment, sampling is performed with a pitch of several mm to several cm. Therefore, the enormous amount of calculation required in the conventional method can be reduced.

[0237] In addition, in the method of the present embodiment, the farther from the display surface 34a, the more the interval (sampling pitch) of the sampling is expanded. Therefore, the method of the present embodiment becomes a method suitable for reproducing a larger space farther from the display surface 34a.

[0238] In the holographic stereogram, a stereoscopic image is produced in a manner that the direction of light rays is reproduced. Therefore, data for displaying a three-dimensional image can be produced from images taken from a plurality of directions. Therefore, using a method of CG (computer graphics) that is being researched by various methods, for an object having a gloss, a transparent object, and the like, not only the shape but also the texture of the object is reproduced. Moreover, by taking an actual object, a stereoscopic image of the actual object can also be reproduced.

[0239] For example, using Figure 29 A method of calculating the pattern of the hologram by a ray tracing method, which is one of the CG methods, will be described. First, the center of each element unit C is taken as the starting point of the light ray shot by the ray tracing method. Next, the ray tracing method is performed from the center of each element unit C as the starting point, and the intersection of the light ray with the object that is the subject is found. Thus, each element unit C has a collection of point light sources from different viewpoint positions, and a pattern of the element unit C having parallax up, down, left, and right can be produced. In addition, the object (subject) here can be a three-dimensional object produced based on three-dimensional information obtained from information taken by the stereo camera SC, or a notional (virtual) object produced by CAD (computer-aided design) or the like. In addition, when only the direction of the light ray is considered at the time of the calculation, the reproduction is performed by the light ray as shown in FIG. 12. On the other hand, when both the direction of the light ray and the distance to the object point are considered at the time of the calculation, the reproduction is performed by the light ray as shown in FIG. 13. Figure 25 Figure 27 Figure 28

[0240] Here, the flow of the process performed by the three-dimensional display 3D of the embodiment will be described using the flowchart of FIG. 14. Figure 33 The flow of the calculation process of the pattern of the hologram when the direction of the light ray and the distance to the object point are considered is shown. Figure 33 The flow of the calculation process of the pattern of the hologram when the direction of the light ray and the distance to the object point are considered is shown.

[0241] ​​​First, the three-dimensional display display 3D acquires three-dimensional information of an object to be displayed on the display (step S10). Next, the three-dimensional display display 3D finds a position of a center of an elemental unit C to be calculated (step Sll), and finds intersections of each line emitted from the origin and having an angle difference of Δα and the object (step S12) with the center position of the elemental unit C as the origin. Then, the three-dimensional display display 3D finds a sum of complex amplitudes of spherical waves spread from each object point at the elemental unit position, using each intersection with the object as an object point (step S13). Further, the complex amplitude found here can be in the range of the size of the elemental unit C.

[0242] The three-dimensional display display 3D performs the above procedures (the procedures of steps Sll to S13) for all the elemental units C (steps S14, S17).

[0243] Then, the three-dimensional display display 3D finds a sum of complex amplitudes of all the elemental units C, and thereby finds a complex amplitude on the display surface 34a (step S15). Next, the three-dimensional display display 3D finds a pattern of interference fringes of the wave surface of the reference light and the complex amplitude on the display surface 34a (step S16). Thereby, the three-dimensional display display 3D can find a pattern of a hologram to be represented on the display.

[0244] In the processing shown in the above flowchart, instead of finding a sum of interference fringe patterns of each elemental unit C, a sum of complex amplitudes is found (step S15), and then, an operation is performed on the sum and the interference fringe pattern of the reference light (step S16). Thereby, the three-dimensional display display 3D can record and reproduce a three-dimensional image of an object as information including both a direction of a light ray and a distance to an object point.

[0245] Further, in the processing shown in the above flowchart, after the sum of complex amplitudes of the elemental unit C is calculated, an operation is performed on the sum and the interference pattern of the reference light, but it is not limited thereto. The three-dimensional display display 3D can also perform an operation on a sum of each interference pattern after the interference pattern of the reference light is calculated for each elemental unit C. In this case, the three-dimensional display display 3D can perform an operation for each elemental unit C. Therefore, a parallel operation becomes easy, and a time required for the operation can be made shorter.

[0246] Further, the recorded stereoscopic image (three-dimensional information of an object) can be a stereogram considering only a horizontal direction parallax, but it is preferable to be a stereogram having a parallax in both a horizontal direction and a vertical direction in order to make an effect of focusing more effective. Further, in the above embodiment, a circular unit is exemplified and described as the elemental unit C, but it is not limited thereto. The shape of the elemental unit C can be a polygonal shape such as a triangular shape, a quadrangular shape, a pentagonal shape, a hexagonal shape, or a star shape, an elliptical shape, a rectangular shape, or the like.

[0247] In addition, as a light source for reproducing the holographic stereogram, a monochromatic light source such as a laser or an LED, or a light source in which a general light source is combined with a filter is preferably used. This is to suppress blurring due to a difference in diffraction angle caused by wavelength.

[0248] In addition, in a case where a laser light source is used as the light source, it is preferable to reduce the speckle. In order to reduce the speckle of the laser light source, methods such as transmission of an optical fiber, vibration of the light source, variation of the optical path length, insertion of a movable diffusion element into the optical path, combination of a plurality of light sources, and the like can be considered.

[0249] In the above, as the social distance SD, a distance of about 1.2 m to 3.6 m is targeted, but it is not necessary to cause all objects reproduced in the space to exist within the range of the distance. It is sufficient that an object that becomes a main observation target exists within the range of the social distance SD. In addition, as a target (object) of reproduction, it is not limited to a person, and can be an animal, a robot, or the like. In addition, the target (object) of reproduction can also be a two-dimensional image reproduced in the space. Furthermore, a building that suggests the existence of a communication target, such as a table, a chair, a desk, or the like arranged in the space can be reproduced. Furthermore, the target of reproduction can not directly communicate. For example, it is possible that a mountain or the like that becomes an observation target when a heavy machine is remotely operated exists within the range of the social distance SD. The same applies to a case where a remote surgery, operation of a robot in a space, operation of an unmanned reconnaissance machine in military affairs, or the like is performed.

[0250] As described using Figure 22 , Figure 23 , even in a case where the depth of the space exceeds 3.6 m, a large space with less blurring can be reproduced using the present application. For example, in order to express a large space such as a landscape, a space including a building, a large plant, or the like, the present application can be utilized in expression of a space exceeding the social distance SD.

[0251] In addition, in a case where the display is observed via an optical system such as an eyepiece lens, the conditions of the size d of the element unit C and the pitch p of the element units can also be corrected based on the magnification of the optical system. For example, in a social distance SD of about 1.2 m to 3.6 m from the display, the size d of the element unit C can be considered to be 1.0 mm and the pitch p of the element unit C can be considered to be 1.2 mm in the absence of an eyepiece lens. In this case, the present embodiment is applied to a head-mounted display or the like, and in a case where the magnification of the eyepiece lens mounted in the head-mounted display or the like is 2 times, the three-dimensional display display 3D corrects the size d of the element unit C to 1.0 / 2 = 0.5 mm and the pitch p of the element unit C to 1.2 / 2 = 0.6 mm. In contrast, in a case where the magnification of the optical system is 0.5 using a reducing optical system, the three-dimensional display display 3D corrects the size d of the element unit C to 1.0 / 0.5 = 2.0 mm and the pitch p of the element unit C to 1.2 / 0.5 = 2.4 mm.

[0252] That is, the corrected size d# and the corrected p# are expressed by the following formulas. In the following formulas, d represents the size before correction, p represents the pitch before correction, and BR represents the magnification of the optical system such as an eyepiece lens.

[0253] d# = d / BR

[0254] p# = p / BR

[0255] In addition, in a case where the display surface 34a is directly observed without using an eyepiece lens or the like, it is preferable that the display surface 34a can be observed by both eyes at the same time in order to obtain the effect of convergence. The average interocular distance is about 60 mm, and thus the size of the display surface 34a is preferably at least 60 mm or more in the long axis direction.

[0256] (Modified Example of the Embodiment)

[0257] Here, a modified example of the embodiment will be described. In the present modified example, the difference from the above-described embodiment is that a virtual object (hereinafter referred to as a virtual object) is reproduced in a reproduction space. The virtual object is, for example, a virtual character or the like.

[0258] Figure 34 is a block diagram showing the configuration of a three-dimensional space display system 1SA of the modified example of the embodiment. The three-dimensional space display system 1SA has, for example, a communication section CM and a three-dimensional display display 3D. That is, in the present modified example, the stereoscopic camera SC can be omitted.

[0259] The communication section CM acquires three-dimensional information of a virtual object from the outside. The virtual object includes not only an object that is an observation target but also three-dimensional information of a space in which a background or the like is reproduced. The three-dimensional display display 3D displays a space in which a virtual object exists at a social distance SD, for example, using the three-dimensional information of the virtual object acquired via the communication section CM.

[0260] Alternatively, the three-dimensional display display 3D can also have a function section that creates three-dimensional information of a virtual object. Alternatively, the three-dimensional display display 3D of the present modification can also use three-dimensional information of a virtual object that is stored in advance in the storage section 36. In this case, the communication section CM can be omitted in the three-dimensional space display system 1S.

[0261] Figure 35 is a diagram that illustrates an example of a three-dimensional space display system 1SA to which the present modification is applied. In Figure 35 , for example, a three-dimensional image of a virtual object generated by the configuration shown in Figure 34 is displayed as a reproduction space SK in which reproduction images SIM (reproduction images SIM1 to SIM7 in this example) exist on a display. In this way, by using the three-dimensional display display 3D of the present modification, it is possible to have a more natural exchange in a social distance space having depth in which a social distance SD is obtained among a non-actually existing object such as a person or a character created in a virtual space, an avatar of an exchange object transmitted from another system, and the like.

[0262] The exchange means in the present modification is not limited to a specific means. For example, the three-dimensional space display system 1SA can also be applied to a means of exchanging with a character. The character here is a virtual character that is displayed as a virtual object.

[0263] In this case, the three-dimensional space display system 1S has, for example, a live camera and a processor that performs signal processing to display a three-dimensional space image in which a character takes a predetermined reaction. The live camera photographs a user. The processor recognizes a gesture of the user from a video photographed by the live camera and decides a reaction to be taken by the character on the basis of the gesture, and displays an image of the character that takes the decided reaction. Thus, it is possible to exchange with the character by means of a gesture.

[0264] Alternatively, the three-dimensional space display system 1SA is provided with a microphone, a speaker, and a processor that performs signal processing for displaying a three-dimensional space image in which a character takes a prescribed reaction. The microphone inputs a user's voice. The processor determines a response to the user's voice input from the microphone, and causes the determined response to be output from the speaker. In addition, the processor determines a reaction for the character to take based on the user's voice, and displays an image of the character taking the determined reaction. Thus, it is possible to communicate with the character by voice.

[0265] In addition, in the present modification, the virtual object can not be a CG (Computer Graphics), but a live-action moving image that is captured in advance using a stereoscopic camera or the like. In this case, it is also possible to switch the moving image reproduced as a reaction in accordance with the input from the user such as the gesture, the voice, and the like as described above, and thus it is possible to interact (communicate) with the virtual object.

[0266] In addition, in a case where the virtual object reproduced (displayed) by the three-dimensional space display system 1SA is a stationary object, the display section 34 of the three-dimensional display 3D can also display an image of a printed matter or the like that does not change (is stationary).

[0267] In addition, the image displayed by the display section 34 of the three-dimensional display 3D can be an image in which a hologram pattern is drawn using a minute drawing device such as an electronic pen drawing device, and further an image in which the drawn hologram pattern is copied. In this way, by using a fixed hologram pattern (stationary image) as the displayed image, it is possible to reproduce a larger space at a low cost. In this case, the display section 34 controls the direction of light by the hologram pattern. The display section 34 displays the hologram pattern as at least one of a virtual image or a real image by the light rays emitted by each element unit C. Thus, the display function and the light control function can be implemented by one device. In this case, it is not possible to cause a virtual character displayed as a virtual object to take a reaction, but it is possible to communicate with the simulated virtual object by voice as described above. In addition, the light control section 35 can display a stationary image such as a fixed hologram pattern together with or instead of the display section 34. The display section 34 is an example of a "stereoscopic image display section". The light control section 35 is an example of a "stereoscopic image display section". In addition, the image in which the hologram pattern is drawn is an example of a "stereoscopic image". The image in which the drawn hologram pattern is copied is an example of a "stereoscopic image".

[0268] As described above, the three-dimensional display 3D (light ray reproducing device) of the embodiment reproduces the light rays virtually emitted from the above-described stereoscopic image in a case where the stereoscopic image is reproduced in the reproduction space SK.

[0269] The three-dimensional display 3D of the embodiment has a display section 34 and / or a light control section 35. The display section 34 and / or the light control section 35 are an example of a "stereoscopic image display section". The display section 34 and / or the light control section 35 display a stereoscopic image as at least either one of a virtual image or a real image by light rays emitted from each of the element units C included in an element unit set composed of a plurality of element units C two-dimensionally arranged in correspondence with a reproduction picture. The display section 34 and / or the light control section 35 display the stereoscopic image in a region in the depth direction in the reproduction space SK where the distance corresponds to the social distance SD. In addition, in the three-dimensional display 3D, the size d of the element unit C and the pitch p of the element unit C are values determined in accordance with the degree at which the stereoscopic image reproduced in the reproduction space SK is observed by the observer OB. The stereoscopic image is reproduced in a region in the depth direction in the reproduction space SK where the distance corresponds to the social distance SD.

[0270] Thus, the three-dimensional display 3D of the embodiment can determine the size d of the element unit C and the pitch p of the element unit C so that the stereoscopic image at the social distance SD in the reproduction space SK is well observed by the observer OB. Therefore, the social distance space can be reproduced as a three-dimensional space in which a natural sense of distance is obtained and blurring is less.

[0271] In addition, the three-dimensional display 3D of the embodiment has a calculation section 31 and / or a control section 32. The calculation section 31 and / or the control section 32 are an example of a "signal processing section". The calculation section 31 and / or the control section 32 calculate the direction of a light ray to be reproduced for each element (element unit C) of the element unit set. The element unit C is two-dimensionally arranged in correspondence with a reproduction picture. Each element obtained by dividing a set composed of a plurality of the above-described light rays emitted from the surface of a stereoscopic image in accordance with the position of the reproduction picture reached by each light ray is associated with the element unit C. Thus, the same effects as the above-described effects can be obtained.

[0272] In addition, in the three-dimensional display 3D of the embodiment, the size d of the element unit C is determined in accordance with the size of blurring generated in the reproduced stereoscopic image. Thus, the size d of the element unit C is determined in a manner that can suppress the blurring to a size that can be permitted, and therefore a stereoscopic image with less blurring can be reproduced.

[0273] In addition, the pitch p of the element unit C is determined in accordance with the resolution on the retina of the observer OB who observes the reproduced stereoscopic image. Thus, the pitch p of the element unit C is determined in a manner that can be focused, and therefore a stereoscopic image that can be focused by the observer OB can be reproduced.

[0274] In addition, the size of the element unit C can be determined as d < p. In addition, the size of the element unit C can be 0.8 mm or more, and the pitch p of the element unit C can be 1.2 mm or less. Thus, in the display of the social distance SD, practical communication without barriers can be performed.

[0275] In addition, the element unit C can be a hologram that records a wave surface from a stereoscopic image.

[0276] The three-dimensional space display system 1S (1SA, 100S) and the three-dimensional display 3D in the above-described embodiments can be implemented by a computer. In this case, a program for implementing the function can be recorded in a recording medium readable by a computer, and the function can be implemented by causing a computer system to read the program recorded in the recording medium and execute the program. In addition, the "computer system" herein includes an OS, a peripheral device, and the like. In addition, the "recording medium readable by a computer" refers to a removable medium such as a floppy disk, a magneto-optical disk, a ROM, a CD-ROM, and the like, a storage device such as a hard disk built in a computer system. In addition, the "recording medium readable by a computer" can include a medium that dynamically holds a program for a short period of time, such as a communication line in the case where a program is transmitted via a network such as the Internet, a telephone line, and the like, and a medium that holds a program for a certain period of time, such as a volatile memory inside a computer system that becomes a server or a client in this case. In addition, the above-described program can be a program for implementing a part of the above-described functions, and can be a program that can implement the above-described functions by being combined with a program already recorded in a computer system, and can be a program implemented using a programmable logic device such as an FPGA.

[0277] The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the specific configuration is not limited to the embodiments, and designs and the like within a range not departing from the gist of the present application are also included.

[0278] Explanation of Reference Signs

[0279] 1, 1A, 1B, 2 diffraction sheet

[0280] 10 substrate

[0281] 20 uncured resin layer (first uncured resin layer)

[0282] 20A uncured resin layer (second uncured resin layer)

[0283] 20B uncured resin layer (third uncured resin layer)

[0284] 21, 41 first diffraction pattern

[0285] 22, 22A, 42 second diffraction pattern

[0286] 30, 30A, 40A diffraction layer

[0287] 40 color filter

[0288] 51, 52 three-dimensional display device

[0289] 100 first edition

[0290] 100a first diffraction pattern

[0291] 110 first mask

[0292] 110a opening (first opening)

[0293] 200 second edition

[0294] 200a second diffraction pattern

[0295] 210 second mask

[0296] 210a opening (second opening)

[0297] LC liquid crystal device

[0298] 1S, 1SA, 100S … three-dimensional space display system

[0299] CM … communication section

[0300] SC … stereoscopic camera

[0301] 3D … three-dimensional display display (ray reproduction device)

[0302] 31 … arithmetic section (signal processing section)

[0303] 32 … control section (signal processing section)

[0304] 33 … light source section

[0305] 34 … display section (stereoscopic image display section)

[0306] 35 … light control section (stereoscopic image display section)

[0307] 36 … storage section

[0308] C … element unit

[0309] OB … observer

[0310] SD … social distance

[0311] d … size of element unit

[0312] p … pitch of element unit

Claims

1. A light ray reproducing apparatus that reproduces light rays virtually emitted from a stereoscopic image in a case where the stereoscopic image is displayed in a reproduction space, wherein a stereoscopic image display section that displays the stereoscopic image as at least either of a virtual image or a real image by light rays emitted from each element cell included in an element cell set composed of a plurality of element cells two-dimensionally arranged in correspondence with a reproduction screen to which a plurality of the light rays emitted from a surface of the stereoscopic image arrive, the stereoscopic image display section displays the stereoscopic image in a region in the reproduction space where a distance in a depth direction corresponds to a social distance, a size of each element in the element cell set, that is, the element cell, and a pitch of the element cells when the element cells are two-dimensionally arranged, are values determined in accordance with a degree at which the stereoscopic image displayed in the reproduction space is observed by an observer.

2. The light ray reproducing apparatus according to claim 1, wherein a signal processing section that divides a set composed of a plurality of the light rays emitted from the surface of the stereoscopic image in accordance with a position of the reproduction screen, establishes correspondence between each element of the plurality of the light rays after the division and each element of the element cell set, and performs an operation on components of one or more of the light rays reproduced with respect to each element of the element cell set.

3. The light ray reproducing apparatus according to claim 1 or 2, wherein the size of the element cell is determined in accordance with a size of blur generated in the displayed stereoscopic image in a case where the stereoscopic image is displayed in a region in the reproduction space where a distance in a depth direction corresponds to a social distance.

4. The light ray reproducing apparatus according to any one of claims 1 to 3, wherein the pitch of the element cells is determined in accordance with a resolution on a retina of an observer who observes the displayed stereoscopic image in a case where the stereoscopic image is displayed in a region in the reproduction space where a distance in a depth direction corresponds to a social distance.

5. The light ray reproducing apparatus according to any one of claims 1 to 4, wherein the size of the element cell is determined to be smaller than the pitch of the element cells.

6. The light ray reproducing apparatus according to any one of claims 1 to 5, wherein the size of the element cell is 0.8 mm or more.

7. The light ray reproducing apparatus according to any one of claims 1 to 6, wherein the pitch of the element cells is 1.2 mm or less.

8. The light ray reproducing apparatus according to any one of claims 1 to 7, wherein the element cell is a hologram that records a wave surface from the stereoscopic image.

9. A three-dimensional spatial display system, wherein, comprises: the light ray reproducing apparatus according to any one of claims 1 to 8; and a stereoscopic camera that outputs three-dimensional information of the stereoscopic image to the light ray reproducing apparatus.

10. A light ray reproduction method, which is a light ray reproduction method of a light ray reproduction apparatus that reproduces light rays virtually emitted from a stereoscopic image in a case where the stereoscopic image is displayed in a reproduction space, and has a stereoscopic image display section that displays the stereoscopic image as at least either of a virtual image or a real image by light rays emitted from each element unit included in an element unit set composed of a plurality of element units two-dimensionally arranged in correspondence with a reproduction screen, in the light ray reproduction method, the stereoscopic image display section displays the stereoscopic image in a region in a depth direction in the reproduction space that corresponds to a social distance, a size of each element, that is, an element unit, in the element unit set and a pitch of the element units when the element units are two-dimensionally arranged are values determined in accordance with a degree at which the stereoscopic image displayed in the reproduction space is observed by an observer, a signal processing section divides a set composed of a plurality of the light rays emitted from a surface of the stereoscopic image in accordance with a position of the reproduction screen, establishes correspondence between each element of the plurality of the light rays after the division and each element of the element unit set, and performs an operation on components of one or more of the light rays reproduced with respect to each element of the element unit set.

11. A program that causes a computer of a light ray reproduction apparatus to function as a signal processing section, in which, the light ray reproduction apparatus reproduces light rays virtually emitted from a stereoscopic image in a case where the stereoscopic image is displayed in a reproduction space, and has a stereoscopic image display section that displays the stereoscopic image as at least either of a virtual image or a real image by light rays emitted from each element unit included in an element unit set composed of a plurality of element units two-dimensionally arranged in correspondence with a reproduction screen, the signal processing section divides a set composed of a plurality of the light rays emitted from a surface of the stereoscopic image in accordance with a position of the reproduction screen, establishes correspondence between each element of the plurality of the light rays after the division and each element of the element unit set, and performs an operation on components of one or more of the light rays reproduced with respect to each element of the element unit set, the stereoscopic image display section displays the stereoscopic image in a region in a depth direction in the reproduction space that corresponds to a social distance, a size of each element, that is, an element unit, in the element unit set and a pitch of the element units when the element units are two-dimensionally arranged are values determined in accordance with a degree at which the stereoscopic image displayed in the reproduction space is observed by an observer.

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