Aerial image display system

Abstract

An aerial image display system for displaying an object as an aerial image by using IP technology comprises: an IP image conversion device for generating a first IP image 21A and a second IP image 21B that are configured from two different kinds of element image groups; and an aerial image display device 12 for grouping a plurality of translucent portions 23a and 23b of an IP filter 16 into a first translucent group 24A and a second translucent group 24B that are opened and closed in a time division manner, displaying the first IP image 21A when the plurality of translucent portions 23a included in the first translucent group 24A are opened and the plurality of translucent portions 23b included in the second translucent group 24B are closed, and displaying the second IP image 21B when the plurality of translucent portions 23a included in the first translucent group 24A are closed and the plurality of translucent portions 23b included in the second translucent group 24B are opened.

Description

Aerial image display system

[0001] The present invention relates to an aerial image display system capable of displaying (reproducing) clear aerial images (including three-dimensional (stereoscopic) images and two-dimensional images) that an observer can visually recognize with the same sensation as in daily life without using special glasses by employing Integral Photography (hereinafter referred to as IP) technology.

[0002] Conventionally, one known method for displaying spatial images is the IP method, which displays a spatial image using data (images) that record the optical spatial image of an object. Here, the principle of the IP method will be explained. As shown in Figure 15, light-shielding panels 51 are placed in front of a three-dimensional object (object) 50 at predetermined intervals. Multiple (in this case, three) pinholes 52a to 52c are formed in these light-shielding panels 51. Further in front of the light-shielding panels 51, a photosensitive film 53 is placed parallel to the light-shielding panels 51. There are countless object points on the surface of the three-dimensional object 50 that emit (reflect) light, but here we will focus on three object points 54 to 56. Of the countless rays of light emitted in various directions from each object point 54 to 56, one ray 54a, 55a, and 56a each passes through the pinhole 52a, forming an elemental image 60a consisting of minute images 57a, 58a, and 59a on the photosensitive film 53. Similarly, from the countless rays of light emitted in various directions from each object point 54-56, one ray 54b, 55b, and 56b each passes through the pinhole 52b, forming an elemental image 60b consisting of minute images 57b, 58b, and 59b on the photosensitive film 53, and one ray 54c, 55c, and 56c each passes through the pinhole 52c, forming an elemental image 60c consisting of minute images 57c, 58c, and 59c on the photosensitive film 53. In the IP-type spatial image display method and spatial image display device, an IP image 61 composed of elemental images 60a' to 60c' obtained by inverting these elemental images 60a to 60c by 180 degrees relative to the pinholes 52a to 52c is displayed on a display (image display panel). As a result, by observing the direction of arrow a, the observer will see the light emitted from each elemental image 60a' to 60c' through the pinholes 52a to 52c. In actual spatial image display devices, by increasing the number of pinholes (arranging them at a high density), observers can observe a three-dimensional image (real image) of a three-dimensional object 50 with its surface details accurately represented through countless pinholes.

[0003] However, in conventional IP systems, the amount of light emitted from each small image (element image) and passing through the imaging means varies depending on the size (area) of the small image and the distance from the small image (display screen) to the imaging means. The position where the spatial image is displayed (the distance from the imaging means to the position where the spatial image is formed) also changes according to the distance from the small image to the imaging means. Therefore, once the display resolution (pixel size) and the size of the small image are determined, the optimal distance from the small image to the imaging means is determined, and the brightness and quality (resolution) of the spatial image are also determined. For example, even if the pitch of the imaging means is made finer and the number of imaging means is increased, each imaging means is located in the center of each small image, and the pitch of the imaging means and the pitch of the small image are equal, so the area of ​​each small image becomes smaller, and the amount of light passing through each imaging means decreases. Also, if the area of ​​the small image becomes smaller while the display resolution remains constant, the number of pixels contained in each small image decreases, and the image quality deteriorates. Therefore, in order to obtain a high-definition spatial image, it is necessary to reduce the size of the pixels and increase the number of pixels contained in each small image, but there is a limit to the display resolution. For the reasons mentioned above, it is generally said that it is difficult to obtain a bright and clear spatial image using the IP method.

[0004] As an aerial image (stereoscopic image) display device employing this IP method, for example, Patent Document 1 discloses a display on which small images (element images) each having a plurality of micro-images in divided respective sections are displayed, a shutter panel that has first mechanical shutters arranged side by side in units of micro-images, turned on and off in units of micro-images, and time-divides each section for each small image, and is disposed on the front surface of the display, and an imaging panel on which imaging means (second mechanical shutters) for imaging light from each small image that passes when the first mechanical shutters are on are arranged side by side. Each small image forms a part of a stereoscopic image to be displayed, each small image is provided with an imaging means, each small image consists of a plurality of dispersedly arranged micro-images, and there has been proposed a stereoscopic image display device in which each imaging means is on an axis passing through the central region of the corresponding small image. In Patent Document 1, the screen of one display is divided into a plurality of sections, and each of the plurality of small images displayed in each section is composed of a plurality of dispersedly arranged micro-images, so that the stereoscopic image display device can be made compact, and small images can be arranged at a higher density than in the past. Furthermore, in Patent Document 1, by turning on and off (opening and closing) the first mechanical shutters in units of micro-images and time-dividing each section for each small image, light emitted from the plurality of small images in each section is sequentially selected and extracted at high speed for each small image, thereby sharpening a three-dimensional image and enabling moving image reproduction. Furthermore, in Patent Document 1, an imaging means for passing light emitted from each small image is provided for each small image, and each imaging means is disposed on an axis passing through the central region of the corresponding small image, whereby light emitted from each small image whose display range (position) changes within each section when selected in a time-division manner is extracted from the central region of each respective small image, thereby reducing distortion of the three-dimensional image and suppressing a decrease in light amount.

[0005] International Publication No. WO 2020 / 122053

[0006] However, Patent Document 1 requires a first mechanical shutter and imaging means (second mechanical shutter) to rapidly and sequentially select one small image at a time from among multiple small images displayed in each section. Multiple first mechanical shutters, arranged in each section for minute image units, must be time-division driven for each small image, and the on / off switching of multiple imaging means must be synchronized with the time-division driving of the first mechanical shutters. This results in a complex structure, high cost, complicated control, and difficulty in scaling up the device. Furthermore, in Patent Document 1, multiple small images are displayed in different display ranges (positions) within each section, but the position of each section is fixed, and the spatial image is displayed based on the image information contained in the light obtained for each section, which limits the ability to increase the resolution of the spatial image.

[0007] This invention has been made in view of the above circumstances, and aims to provide a spatial image display system that has a simple structure, does not require complicated control, and can display a bright, high-definition spatial image that can be viewed by an observer with the same sense as in everyday life, without the need for special glasses.

[0008] A spatial image display system according to the present invention that serves the above purpose is a spatial image display system that displays an object as a spatial image using IP technology, comprising: (a) an IP image converter that converts captured images obtained by photographing the object from multiple viewpoints into a group of elemental images, each consisting of multiple elemental images necessary for displaying the spatial image; and (b) a spatial image display unit that integrates an IP image panel having a display surface composed of multiple pixels arranged vertically and horizontally, and an IP filter having multiple light-transmitting parts, which is positioned in front of the display surface of the IP image panel, wherein the IP image converter generates first to nth IP images composed of n different groups of elemental images that complement each other, and the spatial image display unit displays the first to nth IP images sequentially on the IP image panel in a time-division manner, and when the ith IP image is displayed, the light emitted from the ith IP image is transmitted through the light-transmitting parts located at the center of each of the multiple elemental images that constitute the ith IP image when viewed from the front. However, n is an integer of 2 or more, and i is an integer from 1 to n.

[0009] Here, the object can be either a planar image (two-dimensional image) or a three-dimensional image. If the object is an image displayed on an image display device such as a display, the planar image (two-dimensional image) is displayed as the spatial image. If the object is a three-dimensional object, its three-dimensional image is displayed as the spatial image. A liquid crystal display is preferably used as the IP image panel, but it is not limited to this. The shape of each pixel of the IP image panel may be square or rectangular when viewed from the front. If the shape of each pixel of the IP image panel is square when viewed from the front, the length of one side of each pixel is the vertical pitch P of the multiple pixels arranged vertically and horizontally. ｐｙ and lateral pitch P ｐｘ (=P ｐｙ ) becomes equal to ). The light-transmitting portion of the IP filter can be selectively driven (opened and closed) to switch between the presence or absence of light transmission. As such an IP filter, a liquid crystal (LCD) or PDLC (photochromic film) type optical shutter that can switch (adjust) between a transparent state and an opaque state depending on whether or not voltage is applied is preferably used. The liquid crystal or PDLC type optical shutter can make a desired position (region) transparent, thereby allowing that transparent region to function as a light-transmitting portion. Alternatively, a mechanical shutter (MEMS shutter) may be used as the IP filter. The object is preferably a CG image, and the IP image converter can generate a captured image and multiple element images by calculation, treating the object as if it were virtually photographed with a camera. The CG image may be a wireframe or other image created from scratch using a computer, or it may be a real-life image converted into a CG image.

[0010] In the spatial image display system according to the present invention, when n=2, the plurality of element images on the first IP image and the plurality of element images on the second IP image are arranged vertically and horizontally, respectively, arranged in a rectangular shape with vertical dimension a and horizontal dimension b when viewed from the front, by the plurality of pixels of the IP image panel, and the plurality of light-transmitting parts are each formed in the shape of a pinhole and are grouped into a first light-transmitting group and a second light-transmitting group which are driven in a time division, and the plurality of light-transmitting parts of the first light-transmitting group have a vertical pitch P ａ= a, horizontal pitch P ｂ = b, arranged vertically and horizontally, the plurality of light transmitting portions of the second light transmitting group have a vertical pitch P ａ = a, horizontal pitch P ｂ = b, arranged vertically and horizontally, and the second light transmitting group is spaced P in the vertical direction relative to the first light transmitting group ａ / 2 and / or P in the horizontal direction ｂ / 2 offset, it is preferable that only the plurality of light transmitting portions included in the first light transmitting group transmit light emitted from the first IP image, and only the plurality of light transmitting portions included in the second light transmitting group transmit light emitted from the second IP image.

[0011] Here, the shape of each of the plurality of elemental images on the first IP image and the plurality of elemental images on the second IP image may be square or rectangular in front view. For example, in a case where the shape of each pixel of the IP image panel is square in front view, and each elemental image of the first IP image and the second IP image is configured by m (m is an integer of 1 or greater) pixels in both vertical and horizontal directions, the shape of each elemental image in front view has a side length a (= b) that is the vertical pitch P of the pixels of the IP image panel ｐｙ (= horizontal pitch P ｐｘ ) times m, resulting in a square shape, each light transmitting portion is arranged at equal intervals vertically and horizontally corresponding to the position of the central portion of each elemental image, and the vertical pitch P ａ (= horizontal pitch P ｂ ) is equal to the side length a (= b) of each elemental image, and is equal to the vertical pitch P of the pixels of the IP image panel ｐｙ (= horizontal pitch P ｐｘ ) times m.

[0012] In the aerial image display system according to the present invention, when n = 2, the plurality of elemental images on the first IP image and the plurality of elemental images on the second IP image are each formed by the plurality of pixels of the IP image panel into a rectangular shape having a horizontal dimension W in front view and a vertical dimension equal to the vertical dimension of the display surface, and are arranged side by side horizontally; the light transmitting portions are each formed in a vertically elongated slit shape, and are grouped into a first light transmitting group and a second light transmitting group driven in a time-division manner, the plurality of light transmitting portions of the first light transmitting group have a horizontal pitch P Ｗ = W and arranged side by side horizontally, the plurality of light transmitting portions of the second light transmitting group have a horizontal pitch P ＷThe second light-transmitting group is arranged horizontally in a W shape, and the second light-transmitting group is positioned P laterally relative to the first light-transmitting group. Ｗ The light-transmitting parts can also be arranged with a 2x offset, so that only the multiple light-transmitting parts included in the first light-transmitting group allow light emitted from the first IP image to pass through, and only the multiple light-transmitting parts included in the second light-transmitting group allow light emitted from the second IP image to pass through.

[0013] In the spatial image display system according to the present invention, when n=2, the first IP image is composed of a first region first IP image and a second region first IP image, the second IP image is composed of a first region second IP image and a second region second IP image, the first IP image is displayed such that the pixels constituting each of the plurality of element images included in the first region first IP image and the pixels constituting each of the plurality of element images included in the second region first IP image do not overlap, the second IP image is displayed such that the pixels constituting each of the plurality of element images included in the first region second IP image and the pixels constituting each of the plurality of element images included in the second region second IP image do not overlap, and the spatial image display device is configured such that (a) the first region first IP image and the front (b) A polarization unit that linearly polarizes light emitted from the first region second IP image in a first direction and linearly polarizes light emitted from the second region first IP image and the second region second IP image in a second direction perpendicular to the first direction; (b) a first linear polarization filter provided corresponding to the light-transmitting portion located at the center of each of the plurality of element images included in each of the first region first IP image and the first region second IP image when viewed from the front, and which allows only light linearly polarized in the first direction to pass through; and (c) a second linear polarization filter provided corresponding to the light-transmitting portion located at the center of each of the plurality of element images included in each of the second region first IP image and the second region second IP image when viewed from the front, and which allows only light linearly polarized in the second direction to pass through.

[0014] Here, the IP image panel only needs to display images (a first IP image and a second IP image) using light linearly polarized in one direction, and a conventionally known liquid crystal panel (liquid crystal display) can be used as such an IP image panel. Generally, the image displayed on the IP image panel is linearly polarized in one direction parallel to the vertical or horizontal direction of the display surface when viewed from the front. In this case, it is preferable to set the first direction or the second direction in the polarization unit parallel to the direction of linear polarization in the IP image panel. The polarization direction of the first linear polarization filter is made to match the first direction, and the polarization direction of the second linear polarization filter is made to match the second direction. As a result, the light-transmitting section with the first linear polarization filter allows only the light emitted from the first IP image of the first region and the second IP image of the first region (light linearly polarized in a first direction by the polarization unit) to pass through, and the light-transmitting section with the second linear polarization filter allows only the light emitted from the first IP image of the second region and the second IP image of the second region (light linearly polarized in a second direction by the polarization unit) to pass through. Therefore, by combining the first linear polarization filter and the second linear polarization filter with the time-division driven IP filters (first light-transmitting group and second light-transmitting group), it is possible to selectively extract the light emitted from the first IP image of the first region and the light emitted from the first IP image of the second region of the first IP image, and to selectively extract the light emitted from the second IP image of the first region and the light emitted from the second IP image of the second region of the second IP image.

[0015] In the spatial image display system according to the present invention, the plurality of element images on the first IP image and the plurality of element images on the second IP image are each configured in a rectangular shape with vertical dimension a and horizontal dimension b when viewed from the front by a plurality of pixels of the IP image panel and are arranged vertically and horizontally, the plurality of light-transmitting parts are each formed in the shape of a pinhole and are grouped into a first light-transmitting group and a second light-transmitting group which are driven in a time division, and the plurality of light-transmitting parts of the first light-transmitting group have a vertical pitch P ａ = a, lateral pitch P ｂ The multiple light-transmitting parts of the second light-transmitting group are arranged vertically and horizontally at a vertical pitch P = b / 2. ａ = a, lateral pitch Pｂ The second light-transmitting group is arranged vertically and horizontally at a ratio of = b / 2, and the second light-transmitting group is positioned vertically relative to the first light-transmitting group P ａ It is preferable that the light-transmitting parts are arranged with a 2x offset, so that only the multiple light-transmitting parts included in the first light-transmitting group allow light emitted from the first IP image to pass through, and only the multiple light-transmitting parts included in the second light-transmitting group allow light emitted from the second IP image to pass through.

[0016] In the spatial image display system according to the present invention, the first linear polarization filter and the second linear polarization filter have a lateral pitch P ｂ It is even more preferable that they are arranged alternately in vertical stripes at a ratio of = b / 2.

[0017] In the spatial image display system according to the present invention, when n=2, the first IP image is composed of a first region first IP image and a second region first IP image, the second IP image is composed of a first region second IP image and a second region second IP image, the first IP image is displayed such that the pixels constituting each of the plurality of element images included in the first region first IP image and the pixels constituting each of the plurality of element images included in the second region first IP image do not overlap, the second IP image is displayed such that the pixels constituting each of the plurality of element images included in the first region second IP image and the pixels constituting each of the plurality of element images included in the second region second IP image do not overlap, the spatial image display device includes (a) a polarization unit that linearly polarizes the light emitted from the first region first IP image and the first region second IP image in a first direction, and linearly polarizes the light emitted from the second region first IP image and the second region second IP image in a second direction perpendicular to the first direction, and (b) a unit disposed on the light-emitting surface side of the IP filter The IP filter is provided with a polarizer having a polarization axis parallel to the first direction, and the IP filter functions as a first light-transmitting area in a region that overlaps with one or more pixels located at the center of each of the multiple element images included in the first IP image of the first region and one or more pixels located at the center of each of the multiple element images included in the second IP image of the first region when viewed from the front, allowing light linearly polarized in the first direction by the polarization unit and light linearly polarized in the second direction by the polarization unit to pass through as is; and functions as a second light-transmitting area in a region that overlaps with one or more pixels located at the center of each of the multiple element images included in the first IP image of the second region and one or more pixels located at the center of each of the multiple element images included in the second IP image of the second region when viewed from the front, allowing light linearly polarized in the first direction by the polarization unit to pass through after being linearly polarized in the second direction, and light linearly polarized in the second direction by the polarization unit to pass through after being linearly polarized in the first direction.

[0018] Here, the polarization unit and IP filter may use a dynamic optical element that allows the user to select (switch) on a pixel-by-pixel basis of the IP image (first IP image and second IP image) which region allows the incident light to pass through without changing (rotating) its polarization direction, and which region allows the light to pass through after changing (rotating) its polarization direction by 90 degrees. Alternatively, the polarizing unit and IP filter may use a static optical element in which the region allowing the incident light to pass through without changing (rotating) its polarization direction, and which region allows the light to pass through after changing (rotating) its polarization direction by 90 degrees, are predetermined to be fixed on a pixel-by-pixel, row-by-row, or column-by-column basis of the IP image (first IP image and second IP image). Preferably, the dynamic optical element is one that can change the orientation direction of liquid crystal molecules by the presence or absence of voltage application, thereby allowing the user to select whether or not to change (rotate) the polarization direction of the light passing through it by 90 degrees. Preferably, the static optical element is one that utilizes the properties of a λ / 2 wave plate to change (rotate) the polarization direction of only the light passing through a predetermined region selected in advance by 90 degrees, but is not limited to these.

[0019] In the spatial image display system according to the present invention, the polarization unit comprises a first polarization orientation film, a second polarization orientation film positioned opposite the first polarization orientation film, a polarizing liquid crystal layer made of liquid crystal filled between the first polarization orientation film and the second polarization orientation film, and a polarization drive unit capable of switching the orientation direction of the liquid crystal molecules in the polarizing liquid crystal layer on a pixel-by-pixel basis, wherein the orientation processing direction of the first polarization orientation film and the orientation processing direction of the second polarization orientation film are orthogonal to each other.

[0020] In the spatial image display system according to the present invention, the IP filter comprises a first alignment film for shutters, a second alignment film for shutters positioned opposite the first alignment film for shutters, a liquid crystal layer for shutters made of liquid crystal filled between the first alignment film for shutters and the second alignment film for shutters in areas that function as at least the first and second light-transmitting areas, a shutter drive unit capable of switching the orientation direction of the liquid crystal molecules in the liquid crystal layer for shutters on a pixel-by-pixel basis, and a shielding portion that shields areas other than the areas that function as the first and second light-transmitting areas of the liquid crystal layer for shutters, wherein the orientation processing direction of the first alignment film for shutters and the orientation processing direction of the second alignment film for shutters are orthogonal to each other.

[0021] According to the spatial image display system of the present invention, by displaying multiple IP images in a time-division manner (time-division drive), the observer can observe a spatial image synthesized from the light emitted from each of the multiple IP images. Furthermore, by composing one IP image into two regions (first region and second region), and polarizing the light emitted from multiple element images simultaneously displayed in each region in different directions for each region, and selectively extracting it from the light-transmitting section corresponding to each region (image selection by difference in polarization direction), the observer can observe a spatial image synthesized from the light emitted from each of the multiple element images in each region. Therefore, by combining these (time-division drive and image selection by difference in polarization direction), it is possible to display a brighter and higher-definition spatial image compared to reproducing a spatial image from a single IP image, and smooth video playback is also possible.

[0022] This is an explanatory diagram showing the configuration of a spatial image display system according to the first embodiment of the present invention. (A) is a front view of the main part showing the spatial image display unit of the spatial image display system, and (B) is a cross-sectional view taken along the line A-A in (A). (A) and (B) are explanatory diagrams of time-division driving in the spatial image display unit of the spatial image display system. This is a front view of the main part showing a modified example of the spatial image display unit of the spatial image display system. (A) and (B) are explanatory diagrams of time-division driving in a modified example of the spatial image display unit of the spatial image display system. (A) is a front view of the main part showing the first IP image of the first region displayed on the IP image panel of the spatial image display unit of the spatial image display system according to the second embodiment of the present invention, and (B) is a front view of the main part showing the first IP image of the second region displayed on the IP image panel of the spatial image display unit of the spatial image display system. (A) is a front view of the main part showing the second IP image of the first region displayed on the IP image panel of the spatial image display unit of the spatial image display system, and (B) is a front view of the main part showing the second IP image of the second region displayed on the IP image panel of the spatial image display unit of the spatial image display system. This is a schematic exploded perspective view of the main part showing the configuration of the spatial image display unit of the spatial image display system. This is a front view of the main part showing the spatial image display unit of the spatial image display system. This is a front view of the main part of the spatial image display unit in a spatial image display system according to a third embodiment of the present invention. (A) and (B) are explanatory diagrams of time-division driving in the spatial image display unit of the spatial image display system. This is a schematic exploded perspective view of the main part showing the configuration of the spatial image display unit in a spatial image display system according to a fourth embodiment of the present invention. This is a schematic cross-sectional view of the main part showing the first operation of the spatial image display unit in the spatial image display system. This is a schematic cross-sectional view of the main part showing the second operation of the spatial image display unit in the spatial image display system. This is an explanatory diagram showing the principle of the IP method (spatial image reproduction method).

[0023] Next, with reference to the attached drawings, an embodiment of the present invention will be described to facilitate understanding of the present invention. The spatial image display system 10 according to the first embodiment of the present invention shown in Figure 1 displays an object as a spatial image using IP technology. This spatial image display system 10 basically consists of an IP image converter 11 and a spatial image display unit 12.

[0024] The IP image converter 11 converts captured images obtained by photographing an object from multiple viewpoints into a group of elemental images, each consisting of multiple elemental images 13 (see Figures 3(A) and (B)) necessary for displaying a spatial image. The principle for generating multiple elemental images 13 from an object is explained in Figure 15, but computer graphics (CG) images are preferably used as the object, and the IP image converter 11 can generate captured images and multiple elemental images 13 by calculation, assuming that the object is photographed by a virtual camera in the three-dimensional space of the CG image. In this case, the captured images can be considered as images obtained by moving a monocular camera and photographing the object at each position (viewpoint), or as images obtained by fixing a compound camera and photographing the object simultaneously with multiple lenses (multiple viewpoints). The CG image data may be still image data or video data.

[0025] As shown in Figures 1 and 2(A) and (B), the spatial image display unit 12 integrates an IP image panel 15 and an IP filter 16. As shown in Figures 3(A) and (B), the IP image panel 15 has a display surface 18 composed of multiple pixels 17 arranged vertically and horizontally. In this embodiment, the IP image converter 11 generates a first IP image 21A and a second IP image 21B, which are composed of two different groups of element images. As shown in Figures 3(A) and (B), the first IP image 21A and the second IP image 21B each consist of multiple element images 13 arranged vertically and horizontally. The multiple element images 13 on the first IP image 21A and the multiple element images 13 on the second IP image 21B are each composed of multiple pixels 17 of the IP image panel 15 and are arranged vertically and horizontally without gaps. In this embodiment, as shown in Figures 3(A) and (B), the area where one element image 13 is displayed contains four square pixels 17 in both the vertical and horizontal directions when viewed from the front, and the vertical dimension a (= horizontal dimension b) of the element image 13 is the vertical pitch P of the pixels 17 of the IP image panel 15. ｐｙ (= lateral pitch P) ｐｘ This is four times the amount of the previous amount.

[0026] As shown in Figures 2(A) and (B), the IP filter 16 is positioned in front of the display surface 18 of the IP image panel 15 and has a plurality of pinhole-shaped light-transmitting sections 23a and 23b arranged vertically and horizontally. These light-transmitting sections 23a and 23b can be selectively driven (opened and closed) to switch between allowing light to pass through and not allowing it to pass through. The first light-transmitting group 24A, composed of a plurality of light-transmitting sections 23a, and the second light-transmitting group 24B, composed of a plurality of light-transmitting sections 23b, are driven (opened and closed) in a time-division manner, as shown in Figures 3(A) and (B). Figure 3(A) shows the state in which the light-transmitting sections 23a of the first light-transmitting group 24A, shown by solid lines, are open and the light-transmitting sections 23b of the second light-transmitting group 24B, shown by dashed lines, are closed. At this time, each of the plurality of element images 13 that make up the first IP image 21A is displayed by four pixels 17 vertically and horizontally centered on each of the plurality of light-transmitting sections 23a. Furthermore, Figure 3(B) shows a state in which the light-transmitting portion 23a of the first light-transmitting group 24A, shown by the dashed line, is closed, and the light-transmitting portion 23b of the second light-transmitting group 24B, shown by the solid line, is open. At this time, each of the multiple element images 13 that make up the second IP image 21B is displayed by four pixels 17 vertically and horizontally centered on each of the multiple light-transmitting portions 23b. Conventional liquid crystal or PDLC type optical shutters are preferably used as such IP filters, but mechanical shutters (MEMS shutters) may also be used.

[0027] In this embodiment, as shown in Figure 2(A), the multiple light-transmitting portions 23a of the first light-transmitting group 24A have a vertical pitch P ａ , horizontal pitch P ｂ (=P ａ The multiple light-transmitting sections 23b of the second light-transmitting group 24B are arranged vertically and horizontally, with a vertical pitch P ａ , horizontal pitch P ｂ (=P ａ The second light-transmitting group 24B is arranged vertically and horizontally with respect to the first light-transmitting group 24A, and P ａ / 2 and P in the lateral direction ｂ / 2 (=P ａ / 2) They are offset. Also, in this embodiment, as shown in Figure 3(A), one element image 13 is a square composed of 4 pixels 17 vertically and horizontally, so the vertical pitch P of the light-transmitting parts 23a and 23b ａ The transverse pitch P of the light-transmitting portion 23a and the light-transmitting portion 23bｂ Equal to the vertical dimension a and horizontal dimension b of the element image 13 (= vertical pitch and horizontal pitch of the element image 13), and equal to the vertical pitch P of the pixels of the IP image panel 15. ｐｙ (= lateral pitch P) ｐｘ ) is four times that. And, as shown in Figure 2(B), the distance g from the display surface 18 of the IP image panel 15 to the IP filter 16 is the vertical pitch P of the light-transmitting parts 23a and 23b. ａ (= lateral pitch P) ｂ It is preferable that the pore diameter D of the light-transmitting portion 23a and the light-transmitting portion 23b is in the range of 0.5 to 5 times (more preferably 1 to 2 times). Ｈ The vertical pitch P of pixel 17 ｐｙ (= lateral pitch P) ｐｘ It is preferable that it be about 1 to 2 times, but it is not limited to this range.

[0028] Note that the vertical dimension a (= horizontal dimension b) of the element image 13 and the vertical pitch P of the light-transmitting parts 23a and 23b are as follows: ａ (= lateral pitch P) ｂ The vertical and horizontal dimensions of the pixels (= vertical pitch P) are selected as appropriate, and accordingly, the number of pixels 17 included in the element image 13 is also selected as appropriate. Furthermore, the pixels and element images only need to be configured in a rectangular shape (including squares and rectangles) when viewed from the front, and the vertical and horizontal dimensions of the pixels (= vertical pitch P) are also selected. ｐｙ and horizontal pitch P ｐｘ ) and the vertical dimension a and horizontal dimension b of the element image (= vertical pitch P of the light-transmitting part) ａ and horizontal pitch P ｂ The appropriate components are selected as needed. The IP image panel 15 and the IP filter 16 can be integrated by surrounding their outer periphery with a frame (not shown).

[0029] As shown in Figure 1, the spatial image display system 10 includes a display image manipulation means 25 that displays the first IP image 21A and the second IP image 21B generated by the IP image converter 11 on the IP image panel 15, and a light-transmitting section manipulation means 26 that drives (opens and closes) the first light-transmitting group 24A (light-transmitting section 23a) and the second light-transmitting group 24B (light-transmitting section 23b) of the IP filter 16. The IP image converter 11, the display image manipulation means 25, and the light-transmitting section manipulation means 26 together constitute the control unit 27 of the spatial image display system 10. A conventionally known computer is preferably used as the control unit 27. By having the computer execute a predetermined program, the computer functions as the IP image converter 11, the display image manipulation means 25, and the light-transmitting section manipulation means 26, and performs the role of the control unit 27 of the spatial image display system 10. The configuration of the control unit of the spatial image display system is not limited to this embodiment. For example, the first computer may be used as an IP image converter, and the second computer may function as a display image manipulation means and a light-transmitting section manipulation means.

[0030] In the spatial image display system 10 configured as described above, as shown in Figures 3(A) and (B), the spatial image display unit 12 divides the multiple light-transmitting sections 23a and 23b of the IP filter 16 into a first light-transmitting group 24A and a second light-transmitting group 24B, which are driven (opened and closed) in a time-division manner. When the first IP image 21A is displayed on the IP image panel 15, only the multiple light-transmitting sections 23a included in the first light-transmitting group 24A allow the light emitted from the first IP image 21A to pass through. When the second IP image 21B is displayed on the IP image panel 15, only the multiple light-transmitting sections 23b included in the second light-transmitting group 24B allow the light emitted from the second IP image 21B to pass through. In other words, by time-division driven the first light-transmitting group 24A and the second light-transmitting group 24B, the light emitted from each of the multiple element images 13 on the first IP image 21A passes only through the multiple light-transmitting sections 23a of the first light-transmitting group 24A, and the light emitted from each of the multiple element images 13 on the second IP image 21B passes only through the multiple light-transmitting sections 23b of the second light-transmitting group 24B.

[0031] The spatial image display 12 switches between the presence or absence of light passing through the first light-transmitting group 24A and the second light-transmitting group 24B (opening and closing of the light-transmitting parts 23a and 23b) within the eye's afterimage retention time, and displays the first IP image 21A and the second IP image 21B with a time difference. As a result, the observer can observe a bright, high-definition spatial image in which the spatial image reproduced in the first IP image 21A and the spatial image reproduced in the second IP image 21B overlap (within the eye's afterimage retention time). In this embodiment, the second light-transmitting group 24B is positioned vertically and horizontally relative to the first light-transmitting group 24A, respectively. ａ / 2 (=P ｂ / 2) By being offset, the translucent parts 23a and 23b are evenly distributed vertically and horizontally, and a uniform spatial image is reproduced without unevenness. The number and arrangement of translucent parts included in the first translucent group and the second translucent group, as well as the direction and amount of the positional displacement of the second translucent group relative to the first translucent group, are selected as appropriate.

[0032] The screen size of the spatial image display unit 12 (the size of the display surface 18 of the IP image panel 15) is preferably around 32 to 70 inches, but is not limited thereto. For example, a 55-inch spatial image display unit 12 has 2,160 pixels vertically and 3,840 pixels horizontally, with each pixel being 0.315 mm vertically and horizontally. In Figures 3(A) and (B), for explanatory purposes, the case in which the element image 13 is composed of 4 pixels vertically and horizontally 17 is shown, but each element image is preferably composed of, for example, 20 pixels vertically and horizontally, and the vertical pitch P of the light-transmitting sections 23a and 23b in that case is... ａ (= lateral pitch P) ｂ The width is 6.3 mm. Note that the size, number of pixels, pixel size, and pitch of the light-transmitting portion of the spatial image display unit 12 are not limited to this embodiment and can be selected as appropriate.

[0033] Next, a modified version of the spatial image display will be described. The difference between the modified spatial image display 12A and the spatial image display 12 is that, as shown in Figure 4, the second light-transmitting group 24B (multiple light-transmitting sections 23b) of the IP filter 16A is P only in the vertical direction relative to the first light-transmitting group 24A (multiple light-transmitting sections 23a). ａThe points are positioned with a 2x offset. As shown in Figures 5(A) and (B), the spatial image display unit 12A can display the first IP image 21A and the second IP image 21B with a time difference by switching the presence or absence of light passing through the first light-transmitting group 24A and the second light-transmitting group 24B (opening and closing of the light-transmitting parts 23a and 23b). The observer can observe a spatial image in which the spatial image reproduced in the first IP image 21A and the spatial image reproduced in the second IP image 21B overlap. Here, the second light-transmitting group 24B is positioned only in the vertical direction relative to the first light-transmitting group 24A. ａ Because they are positioned with a 2-point offset, the observed spatial image has lower horizontal resolution compared to vertical resolution, but it is clearer than the spatial image reconstructed using only the first IP image 21A or the second IP image 21B.

[0034] In this modified example, the second light-transmitting group 24B is positioned P only in the longitudinal direction relative to the first light-transmitting group 24A. ａ Although they are positioned with a 2x offset, as another modification, the second light-transmitting group 24B is positioned P only in the lateral direction relative to the first light-transmitting group 24A. ｂ / 2 (=P ａ / 2) They may be arranged in a staggered manner. In this embodiment (Figures 2 and 3), the light-transmitting portions 23a of the first light-transmitting group 24A are spaced equally apart vertically and horizontally (vertical pitch P ａ = Horizontal pitch P ｂ ) are arranged in a manner, and multiple light-transmitting parts 23b of the second light-transmitting group 24B are spaced equally apart vertically and horizontally (vertical pitch P ａ = Horizontal pitch P ｂ The second light-transmitting group 24B is arranged in the vertical and horizontal directions relative to the first light-transmitting group 24A, and P ａ / 2 (=P ｂ / 2) The case where they are offset has been explained, but the vertical pitch P of the light-transmitting parts 23a and 23b ａ and horizontal pitch P ｂ They may be different, and the second transparent group is perpendicular to the first transparent group in the direction P ａ / 2 are offset or positioned horizontally P ｂ Even if they are offset by 2, the same action and effect as in this embodiment can be obtained.

[0035] Next, with reference to Figures 6 to 9, the spatial image display unit 12B of the spatial image display system according to the second embodiment of the present invention will be described. Note that components similar to those in the first embodiment are denoted by the same reference numerals and their descriptions are omitted. The differences between the spatial image display unit 12B and the spatial image display unit 12 are that, as shown in Figure 6, the first IP image 21C displayed on the IP image panel 15 consists of a first region first IP image 28A and a second region first IP image 28B; as shown in Figure 7, the second IP image 21D displayed on the IP image panel 15 consists of a first region second IP image 29A and a second region second IP image 29B; and as shown in Figure 8, the first region first IP image 28A and the first region second IP image The system includes a polarization unit 30 that linearly polarizes light emitted from image 29A in a first direction and linearly polarizes light emitted from the second region first IP image 28B and the second region second IP image 29B in a second direction perpendicular to the first direction, and, as shown in Figures 8 and 9, includes a first linear polarization filter 31a that allows only light linearly polarized in the first direction to pass through, and a second linear polarization filter 31b that allows only light linearly polarized in the second direction to pass through. The IP image panel 15 and the polarization unit 30 are arranged in close contact.

[0036] As shown in Figures 6(A) and (B), the IP image panel 15 displays the first IP image 28A of the first region and the first IP image 28B of the second region simultaneously by arranging the pixels 17 that constitute each of the multiple element images 13 included in the first region first IP image 28A (hatched area to the right) and the pixels 17 that constitute each of the multiple element images 13 included in the second region first IP image 28B (hatched area to the left) so that they do not overlap. Therefore, in the actual IP image panel 15, the first IP image 28A of the first region shown in Figure 6(A) and the first IP image 28B of the second region shown in Figure 6(B) are displayed as a single first IP image 21C without overlapping. At this time, linearly polarized light in a first direction is emitted from the first IP image 21C (first IP image 28A of the first region and first IP image 28B of the second region).

[0037] Similarly, as shown in Figures 7(A) and 7(B), the IP image panel 15 displays the first region second IP image 29A and the second region second IP image 29B simultaneously by arranging the pixels 17 that constitute each of the multiple element images 13 included in the first region second IP image 29A (right diagonal hatching area) and the pixels 17 that constitute each of the multiple element images 13 included in the second region second IP image 29B (left diagonal hatching area) so that they do not overlap. Therefore, in the actual IP image panel 15, the first region second IP image 29A shown in Figure 7(A) and the second region second IP image 29B shown in Figure 7(B) are displayed as a single second IP image 21D without overlapping. At this time, linearly polarized light in the first direction is emitted from the second IP image 21D (first region second IP image 29A and second region second IP image 29B).

[0038] In this embodiment, the pixels 17 constituting the first IP image 28A of the first region and the first IP image 28B of the second region are arranged in a checkerboard pattern (alternating) with a one-pixel offset in both the vertical and horizontal directions so as not to overlap with each other, and the pixels 17 constituting the second IP image 29A of the first region and the second IP image 29B of the second region are arranged in a checkerboard pattern (alternating) with a one-pixel offset in both the vertical and horizontal directions so as not to overlap with each other. However, these arrangements are not limited to this embodiment and can be selected as appropriate. Similarly, the arrangement of the element images 13 constituting the first IP image 21C and the second IP image 21D is not limited to this embodiment and can be selected as appropriate. Here, the light emitted from an image displayed on a conventionally known liquid crystal panel (liquid crystal display) is generally linearly polarized in one direction parallel to the vertical or horizontal direction of the display surface when viewed from the front. Therefore, by using an existing liquid crystal panel as the IP image panel 15, the first IP image 21C and the second IP image 21D can be displayed in time division by linearly polarized light such that the direction parallel to the vertical or horizontal direction of the display surface 18 is the first direction.

[0039] As shown in Figure 8, the polarization unit 30 is positioned between the IP image panel 15 and the IP filter 16B and includes a first polarization alignment film 32a, a second polarization alignment film 32b positioned opposite the first polarization alignment film 32a, and a polarizing liquid crystal layer 33 made of liquid crystal (not shown) filled between the first polarization alignment film 32a and the second polarization alignment film 32b. The polarization unit 30 also includes a polarization drive unit 34 that can switch the orientation direction of the liquid crystal molecules in the polarizing liquid crystal layer 33 on a pixel-by-pixel basis. The polarization drive unit 34 includes an upper electrode 34a positioned on the light-receiving side (IP image panel 15 side) of the first polarization alignment film 32a and a lower electrode 34b positioned on the light-emitting side (light-shielding plate 23 side) of the second polarization alignment film 32b.

[0040] The upper electrode 34a and the lower electrode 34b are formed by creating transparent electrodes 35a and 35b on a transparent substrate, respectively. The transparent electrode 35a of the upper electrode 34a and the transparent electrode 35b of the lower electrode 34b are arranged orthogonally. This allows for selective switching of the voltage on and off (presence or absence of voltage application) for the liquid crystal molecules of the polarizing liquid crystal layer 33 at a pixel-17 unit level. Furthermore, the orientation processing direction of the first polarizing alignment film 32a and the orientation processing direction of the second polarizing alignment film 32b are orthogonal to each other. Specifically, the orientation groove 36a formed in the first polarizing alignment film 32a and the orientation groove 36b of the second polarizing alignment film 32b are arranged orthogonally.

[0041] When the voltage between the upper electrode 34a and the lower electrode 34b is off (no voltage applied), the liquid crystal molecules of the polarizing liquid crystal layer 33 sandwiched between the first polarizing alignment film 32a and the second polarizing alignment film 32b align along the alignment groove 36a on the side of the first polarizing alignment film 32a and align along the alignment groove 36b on the side of the second polarizing alignment film 32b. As a result, when the voltage between the upper electrode 34a and the lower electrode 34b is off (no voltage applied), the alignment direction of the liquid crystal molecules of the polarizing liquid crystal layer 33 sandwiched between the first polarizing alignment film 32a and the second polarizing alignment film 32b is gradually twisted from the first polarizing alignment film 32a toward the second polarizing alignment film 32b, and is finally twisted by 90 degrees. In this way, light passing through the polarizing liquid crystal layer 33, in which the alignment direction of the liquid crystal molecules is twisted by 90 degrees, is twisted by 90 degrees along the alignment direction of the liquid crystal molecules. As a result, the direction of linear polarization changes (rotates) by 90 degrees before and after passing through the polarizing liquid crystal layer 33.

[0042] In contrast, when the voltage between the upper electrode 34a and the lower electrode 34b is ON (voltage applied), the liquid crystal molecules sandwiched between the first polarizing alignment film 32a and the second polarizing alignment film 32b align in an upright position (along the electric field) perpendicular to the first polarizing alignment film 32a and the second polarizing alignment film 32b. Thus, light passing through the polarizing liquid crystal layer 33, where the alignment direction of the liquid crystal molecules is perpendicular to the first polarizing alignment film 32a and the second polarizing alignment film 32b, travels in a straight line along the alignment direction of the liquid crystal molecules, and therefore the direction of linear polarization does not change before and after passing through the polarizing liquid crystal layer 33.

[0043] The structure of the polarization drive unit 34 in the polarization unit 30 can be appropriately selected and used from structures similar to those of conventionally known drive units in liquid crystal displays. In this embodiment, the transparent electrodes 35a are arranged along the column direction (vertically) and the transparent electrodes 35b are arranged along the row direction (horizontally), but the arrangement of transparent electrodes 35a and 35b may be reversed. In this embodiment, a simple matrix drive method is used as the drive method for the polarization drive unit 34, but an active matrix drive method (TFT) may also be used. In this embodiment, the alignment groove 36a of the first polarization alignment film 32a is horizontal and the alignment groove 36b of the second polarization alignment film 32b is vertical, but the arrangement direction of the alignment grooves 36a and 36b is not limited to this, and it is sufficient if the alignment grooves 36a and 36b are orthogonal.

[0044] As explained earlier, when the voltage between the upper electrode 34a and the lower electrode 34b is off (no voltage applied), the direction of linear polarization changes by 90 degrees before and after passing through the polarizing liquid crystal layer 33. When the voltage between the upper electrode 34a and the lower electrode 34b is on (voltage applied), the direction of linear polarization does not change before and after passing through the polarizing liquid crystal layer 33. In this embodiment, since linearly polarized light is emitted from the first IP image 21C and the second IP image 21D in a first direction, the polarization unit 30 can turn on (apply voltage) the voltage between the upper electrode 34a and the lower electrode 34b corresponding to the pixels 17 used to display the first IP image 28A and the second IP image 29A of the first region, and turn off (do not apply voltage) the voltage between the upper electrode 34a and the lower electrode 34b corresponding to the pixels 17 used to display the first IP image 28B and the second IP image 29B of the second region, thereby linearly polarizing the light emitted from the first IP image 28A and the second IP image 29A of the first region in a first direction (more precisely, allowing the light linearly polarized in the first direction to pass through as is), and linearly polarizing the light emitted from the first IP image 28B and the second IP image 29B of the second region in a second direction perpendicular to the first direction.

[0045] In the IP filter 16B, as shown in Figure 9, the multiple light-transmitting sections 23a of the first light-transmitting group 24A are arranged at a vertical pitch P ａ= a, lateral pitch P ｂ The multiple light-transmitting portions 23b of the second light-transmitting group 24B are arranged at a / 2, with a vertical pitch P ａ = a, lateral pitch P ｂ The arrangement is a / 2, and the second transparent group 24B is P only in the vertical direction relative to the first transparent group 24A. ａ They are positioned with a shift of / 2 = a / 2. In other words, in the IP filter 16B, the light-transmitting sections 23a of the first light-transmitting group 24A and the light-transmitting sections 23b of the second light-transmitting group 24B are arranged alternately in one row each, and the first linear polarizing filter 31a and the second linear polarizing filter 31b are arranged alternately in one row each so as to be perpendicular to them. The first linear polarizing filter 31a and the second linear polarizing filter 31b are positioned so as to cover the light-transmitting sections 23a and 23b of each row. Therefore, the first linear polarizing filter 31a and the second linear polarizing filter 31b have a lateral pitch P ｂ The values ​​are arranged alternately in vertical stripes at a / 2.

[0046] As the IP filter 16B, a conventionally known liquid crystal or PDLC optical shutter is preferably used, but a mechanical shutter (MEMS shutter) may also be used. However, the liquid crystal optical shutter does not have a polarizing plate and switches only between light transmission and opacity without changing the polarization direction of the incoming light. The arrangement of the light-transmitting section, the first linear polarizing filter, and the second linear polarizing filter is not limited to this embodiment and can be appropriately selected according to the arrangement of the element images constituting the first IP image (first IP image of the first region and first IP image of the second region) and the second IP image (second IP image of the first region and second IP image of the second region).

[0047] The first linear polarizing filter 31a has a polarization axis (not shown) parallel to the first direction, and the second linear polarizing filter 31b has a polarization axis (not shown) parallel to the second direction. As a result, the first linear polarizing filter 31a can pass only light emitted from the first IP image 28A and the second IP image 29A of the first region, and the second linear polarizing filter 31b can pass only light emitted from the first IP image 28B and the second IP image 29B of the second region.

[0048] In this embodiment as well, similar to the first embodiment, the first IP image 21C and the second IP image 21D can be displayed with a time difference by driving (opening and closing) the first light-transmitting group 24A and the second light-transmitting group 24B in a time-division manner. In Figures 6(A) and (B), the light-transmitting section 23a, indicated by solid and black circles, is passable to light (open state), and the light-transmitting section 23b, indicated by dashed circles, is not passable to light (closed state). In Figures 7(A) and (B), the light-transmitting section 23a, indicated by dashed circles, is not passable to light (closed state), and the light-transmitting section 23b, indicated by solid and black circles, is passable to light (open state). In Figure 8, the light-transmitting section 23a, indicated by solid lines, is passable to light (open state), and the light-transmitting section 23b, indicated by dashed lines, is not passable to light (closed state).

[0049] First, as shown in Figures 6(A) and (B), the spatial image display unit 12B opens the multiple light-transmitting sections 23a included in the first light-transmitting group 24A and closes the multiple light-transmitting sections 23b included in the second light-transmitting group 24B to display the first IP image 21C. Then, as previously explained, the polarization unit 30 linearly polarizes the light emitted from the first IP image 28A in the first region in a first direction, and linearly polarizes the light emitted from the first IP image 28B in the second region in a second direction perpendicular to the first direction.

[0050] In Figure 6(A), light emitted from the first region of the first IP image 28A of the first IP image 21C (linearly polarized light in the first direction) enters the light-transmitting portion 23a (solid circle and black circle) of the first light-transmitting group 24A. However, of the light-transmitting portions 23a of the first light-transmitting group 24A, only the light-transmitting portion 23a (solid circle) that overlaps with the first linearly polarizing filter 31a (see Figure 9) can pass the light emitted from the first region of the first IP image 28A, while the light-transmitting portion 23a (black circle) that overlaps with the second linearly polarizing filter 31b (see Figure 9) cannot pass the light emitted from the first region of the first IP image 28A.

[0051] Furthermore, in Figure 6(B), light emitted from the second region of the first IP image 28B of the first IP image 21C (light linearly polarized in the second direction) enters the light-transmitting portion 23a (solid circle and black circle) of the first light-transmitting group 24A. However, of the light-transmitting portions 23a of the first light-transmitting group 24A, only the light-transmitting portion 23a (solid circle) that overlaps with the second linearly polarizing filter 31b (see Figure 9) can pass the light emitted from the second region of the first IP image 28B, while the light-transmitting portion 23a (black circle) that overlaps with the first linearly polarizing filter 31a (see Figure 9) cannot pass the light emitted from the second region of the first IP image 28B.

[0052] With the above configuration, as shown in Figure 6(A), the observer can see the light emitted by the multiple element images 13 constituting the first IP image 28A of the first region through only the light-transmitting portion 23a (solid circle) located at the center of each element image 13, and as shown in Figure 6(B), the observer can see the light emitted by the multiple element images 13 constituting the first IP image 28B of the second region through only the light-transmitting portion 23a (solid circle) located at the center of each element image 13. Therefore, the observer can ultimately observe a bright, low-distortion, high-definition spatial image obtained by combining the first IP image 28A of the first region and the first IP image 28B of the second region.

[0053] Next, as shown in Figures 7(A) and (B), the spatial image display unit 12B closes the multiple light-transmitting sections 23a (dashed circles) included in the first light-transmitting group 24A and opens the multiple light-transmitting sections 23b (solid circles and black circles) included in the second light-transmitting group 24B to display the second IP image 21D. Then, as previously explained, the polarization unit 30 linearly polarizes the light emitted from the second IP image 29A of the first region in a first direction and linearly polarizes the light emitted from the second IP image 29B of the second region in a second direction perpendicular to the first direction.

[0054] In Figure 7(A), light emitted from the first region of the second IP image 29A of the second IP image 21D (light linearly polarized in the first direction) enters the light-transmitting portion 23b (solid circle and black circle) of the second light-transmitting group 24B. However, of the light-transmitting portions 23b of the second light-transmitting group 24B, only the light-transmitting portion 23b (solid circle) that overlaps with the first linearly polarizing filter 31a (see Figure 9) can pass the light emitted from the first region of the second IP image 29A, while the light-transmitting portion 23b (black circle) that overlaps with the second linearly polarizing filter 31b (see Figure 9) cannot pass the light emitted from the first region of the second IP image 29A.

[0055] Furthermore, in Figure 7(B), light emitted from the second region second IP image 29B of the second IP image 21D (light linearly polarized in the second direction) enters the light-transmitting portion 23b (solid circle and black circle) of the second light-transmitting group 24B. However, of the light-transmitting portions 23b of the second light-transmitting group 24B, only the light-transmitting portion 23b (solid circle) that overlaps with the second linearly polarizing filter 31b (see Figure 9) can pass the light emitted from the second region second IP image 29B, while the light-transmitting portion 23b (black circle) that overlaps with the first linearly polarizing filter 31a (see Figure 9) cannot pass the light emitted from the second region second IP image 29B.

[0056] With the above configuration, as shown in Figure 7(A), the observer can see the light emitted by the multiple element images 13 constituting the second IP image 29A of the first region through only the light-transmitting portion 23b (solid circle) located at the center of each element image 13, and as shown in Figure 7(B), the observer can see the light emitted by the multiple element images 13 constituting the second IP image 29B of the second region through only the light-transmitting portion 23b (solid circle) located at the center of each element image 13. Therefore, the observer can ultimately observe a bright, low-distortion, high-definition spatial image obtained by combining the second IP image 29A of the first region and the second IP image 29B of the second region.

[0057] As explained above, the spatial image display 12B can generate bright, low-distortion, high-definition spatial images using the first IP image 21C and the second IP image 21D, respectively. By displaying the first IP image 21C and the second IP image 21D, which are complementary to each other, in a time-division manner within the afterimage retention time of the eye, it is possible to display spatial images that are significantly brighter, clearer, and higher resolution compared to conventional spatial image displays. Furthermore, since high-definition spatial images can be switched and displayed continuously in a short time (for example, 30 to 240 frames / second), smooth video playback is also possible.

[0058] In this embodiment, the first linear polarizing filter 31a and the second linear polarizing filter 31b are arranged alternately in a vertical stripe pattern, but their shape, size, and arrangement can be appropriately selected according to the arrangement of the light-transmitting sections 23a and 23b. Also, in this embodiment, both the first linear polarizing filter 31a and the second linear polarizing filter 31b are placed on the light-emitting side (front side) of the IP filter 16B, but they may also be placed on the light-receiving side (back side = polarizing unit 30 side) of the IP filter 16B, or one may be placed on the light-emitting side of the IP filter 16B and the other on the light-receiving side of the IP filter 16B. In this embodiment, since the element image 13 is a square with side length a when viewed from the front, the vertical pitch P of the light-transmitting sections 23a and 23b ａ = a, lateral pitch P ｂ Although it is given as = a / 2, the element image only needs to be composed of a quadrilateral shape (including squares and rectangles) with vertical dimension a and horizontal dimension b when viewed from the front, and the vertical pitch P of the light-transmitting parts 23a and 23b ａ = a, lateral pitch P ｂ This can be expressed as = b / 2.

[0059] Next, with reference to Figures 10 and 11, the spatial image display unit 12C of the spatial image display system according to the third embodiment of the present invention will be described. Note that components similar to those in the first and second embodiments are denoted by the same reference numerals and their descriptions are omitted. The difference between the spatial image display unit 12C and the spatial image display unit 12 is that, as shown in Figure 10, the light-transmitting portions 23c and 23d of the IP filter 16C are formed in a vertically elongated slit shape, and the plurality of light-transmitting portions 23c constituting the first light-transmitting group 24C are arranged at a horizontal pitch P Ｗ Multiple light-transmitting sections 23d, which constitute the second light-transmitting group 24D, are arranged horizontally in a W shape and have a lateral pitch P Ｗ The elements are arranged horizontally in a W shape, and the second light-transmitting group 24D is positioned laterally to the first light-transmitting group 24C in a P direction. Ｗ The points are offset by 2. The first light-transmitting group 24C (multiple light-transmitting sections 23c) and the second light-transmitting group 24D (multiple light-transmitting sections 23d) can be selectively driven (opened and closed) to switch between the presence or absence of light transmission.

[0060] Furthermore, in the spatial image display unit 12C, the multiple element images 13A on the first IP image 21C and the multiple element images 13B on the second IP image 21D are arranged horizontally in a rectangular shape with a horizontal dimension W and a vertical dimension equal to the vertical dimension of the display surface 18, using multiple pixels 17 of the IP image panel 15. Each light-transmitting part 23c of the first light-transmitting group 24C is positioned at a location corresponding to the center (widthwise center) of each of the multiple element images 13A on the first IP image 21C when viewed from the front, and each light-transmitting part 23d of the second light-transmitting group 24D is positioned at a location corresponding to the center (widthwise center) of each of the multiple element images 13B on the second IP image 21D when viewed from the front. Therefore, the horizontal pitch P of the light-transmitting parts 23c and 23d Ｗ This is equal to the horizontal dimension W of element image 13A and element image 13B. The width D of the slit-shaped light-transmitting portion 23c and light-transmitting portion 23d. Ｗ The horizontal pitch P of pixel 17 ｐｘ It is preferable that it be about 1 to 2 times, but it is not limited to this range. Also, the vertical dimensions of the light-transmitting parts 23c and 23d are equal to the vertical dimensions of the display surface 18, similar to the vertical dimensions of the element images 13A and 13B.

[0061] The above-mentioned multiple element images 13A and multiple element images 13B can be generated, for example, by placing a virtual camera facing (directly facing) the CG image of the object at the center of the CG image in the height direction, moving it horizontally from one side to the other in the width direction of the CG image (for example, from the left end to the right end), capturing vertically elongated images (slit images) from multiple viewpoints, and converting the obtained captured images into two different groups of element images by the IP image converter 11. The horizontal dimension W of element images 13A and element images 13B and the horizontal pitch P of the light-transmitting parts 23c and 23d Ｗ The elements are selected as appropriate, and accordingly, the number of pixels 17 included in element image 13A and element image 13B are also selected as appropriate.

[0062] In the spatial image display unit 12C, the first light-transmitting group 24C, which is composed of multiple light-transmitting sections 23c, and the second light-transmitting group 24D, which is composed of multiple light-transmitting sections 23d, are driven (opened and closed) in a time-division manner, as shown in Figures 11(A) and (B). Figure 11(A) shows the state in which the light-transmitting sections 23c of the first light-transmitting group 24C are open and the light-transmitting sections 23d (shaded sections) of the second light-transmitting group 24D are closed. At this time, the first IP image 21C is displayed by multiple element images 13A centered on each of the multiple light-transmitting sections 23c. Figure 11(B) shows the state in which the light-transmitting sections 23c of the first light-transmitting group 24C are closed and the light-transmitting sections 23d of the second light-transmitting group 24D are open. At this time, the second IP image 21D is displayed by multiple element images 13B centered on each of the multiple light-transmitting sections 23d.

[0063] As explained above, in the spatial image display 12, the rectangular element images 13 and the pinhole-shaped light-transmitting parts 23a and 23b are arranged two-dimensionally, vertically and horizontally, respectively. In contrast, in the spatial image display 12C, the vertically elongated rectangular element images 13A and 13B and the slit-shaped light-transmitting parts 23c and 23d are arranged one-dimensionally, horizontally, respectively. Therefore, the spatial image display 12C has a wider vertical viewing angle and a higher brightness of the spatial image compared to the spatial image display 12. Furthermore, the configuration of the first IP image 21C and the second IP image 21D of the spatial image display unit 12C is simplified compared to the first IP image 21A and the second IP image 21B of the spatial image display unit 12. As a result, the number of element images 13A constituting the first IP image 21C and element images 13B constituting the second IP image 21D is reduced compared to the number of element images 13 constituting the first IP image 21A and the second IP image 21B respectively, which reduces the load on the IP image converter 11, improves processing speed, and improves display speed.

[0064] Furthermore, the IP filter 16C having slit-shaped light-transmitting sections 23c and 23d is easier to manufacture and offers superior mass-producibility compared to the IP filter 16 having pinhole-shaped light-transmitting sections 23a and 23b. Therefore, by using the spatial image display unit 12C instead of the spatial image display unit 12, an inexpensive spatial image display system can be realized. In this embodiment, the element images 13A and 13B are formed in a vertically elongated rectangular shape, and the light-transmitting sections 23c and 23d are formed in a vertically elongated slit shape. However, the element images may be formed in a horizontally elongated rectangular shape, and the light-transmitting sections may be formed in a horizontally elongated slit shape. Also, the spatial image display unit 12C can be rotated 90 degrees to reverse its vertical and horizontal orientation.

[0065] Next, with reference to Figures 12 to 14, the spatial image display unit 12D of the spatial image display system according to the fourth embodiment of the present invention will be described. Note that components similar to those in the first to third embodiments are denoted by the same reference numerals and their descriptions are omitted. The spatial image display unit 12D differs from the spatial image display unit 12B in that, instead of the conventionally known IP filter 16B using an optical shutter or mechanical shutter, it is equipped with a liquid crystal shutter type IP filter 16D whose polarization direction can be selected (switched), and instead of the first linear polarization filter 31a and the second linear polarization filter 31b, it is equipped with a polarizer 31c.

[0066] As shown in Figures 13 and 14, the spatial image display unit 12D displays the first IP image 21E and the second IP image 21F in a time-division manner using the IP image panel 15. In the first time period shown in Figure 13, the first IP image 21E (first IP image 28A of the first region and first IP image 28B of the second region) is displayed on the IP image panel 15, and in the second time period shown in Figure 14, the second IP image 21F (second IP image 29A of the first region and second IP image 29B of the second region) is displayed on the IP image panel 15. In Figures 13 and 14, the direction of linear polarization in the first IP image 21E, the second IP image 21F, and the polarization unit 30 is represented by the direction of the hatching, with the first direction being the horizontal direction and the second direction being the vertical direction. Furthermore, in Figures 13 and 14, the IP image panel 15 and the polarization unit 30 are shown spaced apart for illustrative purposes, but in reality, they are positioned in close contact with each other.

[0067] In the first time period shown in Figure 13, the IP filter 16D functions as a first light-transmitting section 23e in the area that overlaps with one or more pixels 17 located at the center of each of the multiple element images 13 included in the first IP image 28A of the first region when viewed from the front, and as a second light-transmitting section 23f in the area that overlaps with one or more pixels 17 located at the center of each of the multiple element images 13 included in the first IP image 28B of the second region when viewed from the front. The first light-transmitting section 23e allows light linearly polarized in a first direction by the polarization unit 30 and light linearly polarized in a second direction by the polarization unit 30 to pass through as is, while the second light-transmitting section 23f allows light linearly polarized in a first direction by the polarization unit 30 to pass through after being linearly polarized in a second direction, and linearly polarizes light linearly polarized in a second direction by the polarization unit 30 to be linearly polarized in a first direction.

[0068] In the second time period shown in Figure 14, the IP filter 16D functions as a first light-transmitting section 23e in the area that overlaps with one or more pixels 17 located at the center of each of the multiple element images 13 included in the second IP image 29A of the first region when viewed from the front, and as a second light-transmitting section 23f in the area that overlaps with one or more pixels 17 located at the center of each of the multiple element images 13 included in the second IP image 29B of the second region when viewed from the front. The first light-transmitting section 23e allows light linearly polarized in a first direction by the polarization unit 30 and light linearly polarized in a second direction by the polarization unit 30 to pass through as is, while the second light-transmitting section 23f allows light linearly polarized in a first direction by the polarization unit 30 to pass through after being linearly polarized in a second direction, and linearly polarizes light linearly polarized in a second direction by the polarization unit 30 to be linearly polarized in a first direction.

[0069] Next, the specific configuration of the IP filter 16D will be described. As shown in Figure 12, the IP filter 16D includes a first alignment film 38a for the shutter, a second alignment film 38b for the shutter positioned opposite the first alignment film 38a for the shutter, and a liquid crystal layer 39 for the shutter in which liquid crystal (not shown) is filled between the first alignment film 38a and the second alignment film 38b for the shutter, in a range that functions as at least a first light-transmitting portion 23e and a second light-transmitting portion 23f. The IP filter 16D also includes a shutter drive unit 40 that can switch the orientation direction of the liquid crystal molecules in the liquid crystal layer 39 on a pixel-by-pixel basis. The shutter drive unit 40 has an upper electrode 40a positioned on the light-receiving side (upper side = polarizing unit 30 side) of the first alignment film 38a for the shutter and a lower electrode 40b positioned on the light-emitting side (lower side) of the second alignment film 38b for the shutter.

[0070] The upper electrode 40a and the lower electrode 40b are formed by creating transparent electrodes 41a and 41b on a transparent substrate, respectively. The transparent electrode 41a of the upper electrode 40a and the transparent electrode 41b of the lower electrode 40b are arranged orthogonally. This allows for selective switching of the voltage on and off (presence or absence of voltage application) for the liquid crystal molecules of the shutter liquid crystal layer 39 at a pixel 17 unit level. Furthermore, the orientation processing direction of the first alignment film 38a for the shutter and the orientation processing direction of the second alignment film 38b for the shutter are orthogonal to each other. Specifically, the alignment groove 42a formed in the first alignment film 38a for the shutter and the alignment groove 42b of the second alignment film 38b for the shutter are arranged orthogonally. In this embodiment, the alignment groove 42a is oriented horizontally and the alignment groove 42b is oriented vertically, but the orientation of the alignment grooves 42a and 42b is not limited to this; it is sufficient that the alignment grooves 42a and 42b are orthogonal to each other.

[0071] Furthermore, as shown in Figures 13 and 14, the IP filter 16D has a shielding portion 43 that shields areas other than those that function as the first light-transmitting portion 23e and the second light-transmitting portion 23f of the liquid crystal layer 39 for the shutter. This shielding portion 43 only needs to be able to shield light. For example, through holes can be formed only in the area overlapping with the first light-transmitting portion 23e and the second light-transmitting portion 23f of a non-transmitting plate material, and liquid crystal can be filled in these holes. A first alignment film 38a and a second alignment film 38b for the shutter can be placed on both sides of the plate, so that areas other than the first light-transmitting portion 23e and the second light-transmitting portion 23f can function as the shielding portion 43. Alternatively, the entire space sandwiched between the first alignment film 38a and the second alignment film 38b for the shutter can be filled with liquid crystal, and the area not overlapping with the first light-transmitting portion 23e and the second light-transmitting portion 23f of the first alignment film 38a and the second alignment film 38b for the shutter can be colored, for example, black to function as a shielding portion 43.

[0072] As shown in Figures 12 to 14, the polarizer 31c is positioned on the light-emitting side of the IP filter 16D. As shown in Figure 12, the polarizer 31c has a polarization axis 44 parallel to the first direction. The polarizer 31c is a conventionally known type and can only allow linearly polarized light in the first direction parallel to the polarization axis 44 to pass through. The spatial image display unit 12D also includes a spacer 45 positioned between the polarization unit 30 and the IP filter 16D, as shown in Figures 12 to 14. The spacer 45 is transparent and light-transmitting, allowing light that has passed through the polarization unit 30 to pass through without reflection, and a synthetic resin with low birefringence is preferably used.

[0073] The operation of the spatial image display unit 12D configured as described above will now be explained. First, in the first time period shown in Figure 13, the IP image panel 15 displays the first IP image 21E, which is composed of the first region first IP image 28A and the second region first IP image 28B, as previously explained. At this time, as shown in Figure 13, the pixels 17 (solid hatched areas) that constitute the element image 13 included in the first region first IP image 28A and the pixels 17 (dashed hatched areas) that constitute the element image 13 included in the second region first IP image 28B are arranged so as not to overlap each other. Linearly polarized light in a first direction is emitted from the first region first IP image 28A and the second region first IP image 28B. The operation (driving method) of the polarization unit 30 is as described in the second embodiment. By switching the polarization drive unit 34 on and off in units of 17 pixels, it is possible to selectively linearly polarize the light emitted from the first IP image 28A of the first region in a first direction (more precisely, to allow the light linearly polarized in the first direction to pass through as is), and to linearly polarize the light emitted from the first IP image 28B of the second region in a second direction perpendicular to the first direction.

[0074] Therefore, as shown in Figure 13, the light emitted from the first IP image 28A in the first region (solid line) passes through the polarizing unit 30, becomes linearly polarized in a first direction, passes through the spacer 45, and enters the IP filter 16D. The light emitted from the first IP image 28B in the second region (dashed line) passes through the polarizing unit 30, becomes linearly polarized in a second direction, and enters the IP filter 16D. In Figure 12, when the voltage between the upper electrode 40a and the lower electrode 40b of the IP filter 16D is ON (voltage applied), the liquid crystal molecules sandwiched between the first alignment film 38a and the second alignment film 38b for the shutter align upright (along the electric field) so as to be perpendicular to the first alignment film 38a and the second alignment film 38b for the shutter. Thus, light passing through the shutter liquid crystal layer 39, in which the alignment direction of the liquid crystal molecules is perpendicular to the first alignment film 38a and the second alignment film 38b for the shutter, travels in a straight line along the alignment direction of the liquid crystal molecules. Therefore, the direction of linear polarization does not change before and after passing through the shutter liquid crystal layer 39.

[0075] In contrast, when the voltage between the upper electrode 40a and the lower electrode 40b is off (no voltage applied), the liquid crystal molecules of the shutter liquid crystal layer 39 sandwiched between the first shutter alignment film 38a and the second shutter alignment film 38b align along the alignment groove 42a on the first shutter alignment film 38a side and along the alignment groove 42b on the second shutter alignment film 38b side. As a result, when the voltage between the upper electrode 40a and the lower electrode 40b is off (no voltage applied), the alignment direction of the liquid crystal molecules of the shutter liquid crystal layer 39 sandwiched between the first shutter alignment film 38a and the second shutter alignment film 38b is gradually twisted from the first shutter alignment film 38a toward the second shutter alignment film 38b, and is finally twisted by 90 degrees. In this way, light passing through the liquid crystal layer 39 for the shutter, in which the alignment direction of the liquid crystal molecules is twisted by 90 degrees, is twisted by 90 degrees along the alignment direction of the liquid crystal molecules. As a result, the direction of linear polarization changes (rotates) by 90 degrees before and after passing through the liquid crystal layer 39 for the shutter.

[0076] Therefore, in the IP filter 16D of Figure 12, by setting the voltage between the upper electrode 40a and the lower electrode 40b corresponding to the first light-transmitting portion 23e to the ON state (voltage applied), the first light-transmitting portion 23e can pass through as is the light emitted from the first region first IP image 28A and linearly polarized in the first direction by the polarization unit 30 (solid line) and the light emitted from the second region first IP image 28B and linearly polarized in the second direction by the polarization unit 30 (dashed line), as shown in Figure 13. Furthermore, in the IP filter 16D shown in Figure 12, by setting the voltage between the upper electrode 40a and the lower electrode 40b corresponding to the second light-transmitting portion 23f to the OFF state (no voltage applied), the second light-transmitting portion 23f, as shown in Figure 13, can pass through the first region first IP image 28A, which is linearly polarized in the first direction by the polarization unit 30 (solid line), after being linearly polarized in the second direction, and can pass through the second region first IP image 28B, which is linearly polarized in the second direction by the polarization unit 30 (dashed line), after being linearly polarized in the first direction.

[0077] However, since a polarizer 31c is positioned on the light-emitting side of the IP filter 16D that allows only light linearly polarized in the first direction to pass through, of the light passing through the first light-transmitting section 23e, only the light emitted from the first IP image 28A in the first region and which has been linearly polarized in the first direction by the polarization unit 30 and passed through the first light-transmitting section 23e (liquid crystal layer 39 for shutter) (solid line) passes through the polarizer 31c and is emitted, while the light emitted from the first IP image 28B in the second region and which has been linearly polarized in the second direction by the polarization unit 30 and passed through the first light-transmitting section 23e (liquid crystal layer 39 for shutter) (dashed line) cannot pass through the polarizer 31c. Furthermore, of the light passing through the second light-transmitting section 23f, the light emitted from the first IP image 28A in the first region, which is linearly polarized in the first direction by the polarization unit 30 and then linearly polarized in the second direction while passing through the second light-transmitting section 23f (solid line), cannot pass through the polarizer 31c. Only the light emitted from the first IP image 28B in the second region, which is linearly polarized in the second direction by the polarization unit 30 and then linearly polarized in the first direction while passing through the second light-transmitting section 23f (dashed line), passes through the polarizer 31c and is emitted. Of the light that has passed through the polarization unit 30, the light that irradiates areas other than the first light-transmitting section 23e and the second light-transmitting section 23f of the IP filter 16D and does not contribute to the imaging of the spatial image is shielded by the shielding section 43 and does not leak out to the outside of the IP filter 16D.

[0078] Next, in the second time period shown in Figure 14, the IP image panel 15 displays the second IP image 21F, which is composed of the first region second IP image 29A and the second region second IP image 29B, as previously described. At this time, as shown in Figure 14, the pixels 17 (dashed hatched areas) that constitute the element image 13 included in the first region second IP image 29A and the pixels 17 (solid hatched areas) that constitute the element image 13 included in the second region second IP image 29B are arranged so as not to overlap each other. Linearly polarized light in the first direction is emitted from the first region second IP image 29A and the second region second IP image 29B. The operation (driving method) of the polarization unit 30 is as described above. By switching the polarization drive unit 34 on and off in units of 17 pixels, it is possible to selectively linearly polarize the light emitted from the second IP image 29A of the first region in a first direction (more precisely, to allow the light linearly polarized in the first direction to pass through as is), and to linearly polarize the light emitted from the second IP image 29B of the second region in a second direction perpendicular to the first direction.

[0079] Therefore, as shown in Figure 14, the light emitted from the second IP image 29A in the first region (dashed line) passes through the polarizing unit 30, becomes linearly polarized in the first direction, passes through the spacer 45, and enters the IP filter 16D. The light emitted from the second IP image 29B in the second region (solid line) passes through the polarizing unit 30, becomes linearly polarized in the second direction, passes through the spacer 45, and enters the IP filter 16D. In the IP filter 16D of Figure 12, by turning on the voltage between the upper electrode 40a and the lower electrode 40b corresponding to the first light-transmitting section 23e (voltage applied), the first light-transmitting section 23e can pass through the light emitted from the second IP image 29A in the first region and linearly polarized in the first direction by the polarizing unit 30 (dashed line) and the light emitted from the second IP image 29B in the second region and linearly polarized in the second direction by the polarizing unit 30 (solid line) as is. Furthermore, in the IP filter 16D shown in Figure 12, by setting the voltage between the upper electrode 40a and the lower electrode 40b corresponding to the second light-transmitting portion 23f to the OFF state (no voltage applied), the second light-transmitting portion 23f, as shown in Figure 14, can pass through the second light-transmitting portion 23f after linearly polarizing light (dashed line) emitted from the second IP image 29A of the first region and linearly polarized in the first direction by the polarization unit 30 in the second direction, and can pass through the second light (solid line) emitted from the second IP image 29B of the second region and linearly polarized in the second direction by the polarization unit 30 in the first direction, linearly polarizing it in the first direction.

[0080] However, since a polarizer 31c is positioned on the light-emitting side of the IP filter 16D that allows only linearly polarized light in the first direction to pass through, of the light passing through the first light-transmitting section 23e, only the light emitted from the first region second IP image 29A and that has passed through the first light-transmitting section 23e (shutter liquid crystal layer 39) while being linearly polarized in the first direction by the polarization unit 30 (dashed line) passes through the polarizer 31c and is emitted, while the light emitted from the second region second IP image 29B and that has passed through the first light-transmitting section 23e (shutter liquid crystal layer 39) while being linearly polarized in the second direction by the polarization unit 30 (solid line) cannot pass through the polarizer 31c. Furthermore, of the light passing through the second light-transmitting section 23f, the light emitted from the second IP image 29A in the first region, which is linearly polarized in the first direction by the polarization unit 30 and then linearly polarized in the second direction while passing through the second light-transmitting section 23f (dashed line), cannot pass through the polarizer 31c. Only the light emitted from the second IP image 29B in the second region, which is linearly polarized in the second direction by the polarization unit 30 and then linearly polarized in the first direction while passing through the second light-transmitting section 23f (solid line), passes through the polarizer 31c and is emitted. Of the light that has passed through the polarization unit 30, the light that irradiates areas other than the first light-transmitting section 23e and the second light-transmitting section 23f of the IP filter 16D and does not contribute to the imaging of the spatial image is shielded by the shielding section 43 and does not leak out to the outside of the IP filter 16D.

[0081] As a result of the above operation, in the first time period, only light emitted from the first region first IP image 28A of the first IP image 21E is emitted from the first light-transmitting section 23e, and only light emitted from the second region first IP image 28B of the first IP image 21E is emitted from the second light-transmitting section 23f. Therefore, in the first time period, the observer sees only the light emitted from each of the multiple element images 13 constituting the first region first IP image 28A through the first light-transmitting section 23e, and sees only the light emitted from each of the multiple element images 13 constituting the second region first IP image 28B through the second light-transmitting section 23f. Furthermore, during the second time period, only the light emitted from the first region of the second IP image 21F (second IP image 29A) is emitted from the first light-transmitting section 23e, and only the light emitted from the second region of the second IP image 21F (second IP image 29B) is emitted from the second light-transmitting section 23f. Therefore, during the second time period, the observer sees only the light emitted from each of the multiple element images 13 constituting the first region of the second IP image 29A through the first light-transmitting section 23e, and sees only the light emitted from each of the multiple element images 13 constituting the second region of the second IP image 29B through the second light-transmitting section 23f.

[0082] In the spatial image display 12D, the first IP image 21E and the second IP image 21F, which complement each other, are displayed in a time-division manner within the eye's afterimage retention time. As a result, the observer can ultimately observe a bright, high-definition spatial image that is reconstructed by combining the light emitted from each of the multiple element images 13 constituting the first region first IP image 28A and the multiple element images 13 constituting the second region first IP image 28B of the first IP image 21E, and the light emitted from each of the multiple element images 13 constituting the first region second IP image 29A and the multiple element images 13 constituting the second region second IP image 29B of the second IP image 21F. Furthermore, by sequentially displaying multiple different first and second IP images using the IP image panel 15, it is possible to play back a continuous, smooth video.

[0083] The present invention has been described above with reference to examples, but the present invention is not limited in any way to the configurations described in the above examples, and includes other examples and modifications that can be considered within the scope of the claims. The IP image panels of Examples 1 to 4 above only need to be able to display an IP image by making each pixel constituting the IP image (element image) emit light. As such an IP image panel, for example, a display using liquid crystal, LED or OLED is preferably used, but is not limited to these. In the above examples, a first IP image and a second IP image composed of two different groups of element images are generated, and the multiple light-transmitting parts of the IP filter are grouped into a first light-transmitting group and a second light-transmitting part that open and close in a time-division manner, and the multiple light-transmitting parts contained in the first light-transmitting group and the second light-transmitting part are opened and closed sequentially in each group to display the first IP image and the second IP image in a time-division manner. However, the number of time divisions may be three or more, and the number of time divisions can be appropriately selected (set) depending on the number of light-transmitting parts, their arrangement and grouping method, making it possible to display three or more IP images sequentially with a time difference.

[0084] According to the present invention, a spatial image display system is provided that has a simple structure, does not require complicated control, and can display a bright, high-definition spatial image that can be viewed by the observer with the same sense as in everyday life, without the need for special glasses, thereby promoting the widespread adoption and expansion of applications of spatial image display systems.

[0085] 10: Spatial image display system, 11: IP image converter, 12: Spatial image display unit, 12A: Spatial image display unit, 12B: Spatial image display unit, 12C: Spatial image display unit, 12D: Spatial image display unit, 13: Element image, 13A: Element image, 13B: Element image, 15: IP image panel, 16: IP filter, 16A: IP filter, 16B: IP filter, 16C: IP filter, 16D: IP filter, 17: Pixel, 18: Display surface, 21A: First IP image, 21B: Second IP image, 21C: First I P image, 21D: second IP image, 21E: first IP image, 21F: second IP image, 23a: transparent section, 23b: transparent section, 23c: transparent section, 23d: transparent section, 23e: first transparent section, 23f: second transparent section, 24A: first transparent group, 24B: second transparent section Light group, 24C: first transparent group, 24D: second transparent group, 25: display image operation means, 26: transparent section operation means, 27: control section, 28A: first area first IP image, 28B: second area first IP image, 29A: first area second IP image, 29B: second area 2I P image, 30: Polarization unit, 31a: First linear polarizing filter, 31b: Second linear polarizing filter, 31c: Polarizer, 32a: First polarization alignment film, 32b: Second polarization alignment film, 33: Polarizing liquid crystal layer, 34: Polarizing drive unit, 34a: Upper electrode, 34b: Lower electrode, 35a: Transparent electrode, 35b: Transparent electrode, 36a: Alignment groove, 36b: Alignment groove, 38a: First alignment film for shutter, 38b: Second alignment film for shutter, 39: Liquid crystal layer for shutter, 40: Drive unit for shutter, 40a: Upper Part electrode, 40b: Lower electrode, 41a: Transparent electrode, 41b: Transparent electrode, 42a: Orientation groove, 42b: Orientation groove, 43: Shielding part, 44: Polarization axis, 45: Spacer, 50: Three-dimensional object (object), 51: Light-shielding panel, 52a-52c: Pinhole, 53: Photosensitive film, 54-56: Object point, 54a-54c, 55a-55c, 56a-56c: Light ray, 57a-57c, 58a-58c, 59a-59c: Micro-image, 60a-60c: Element image, 60a'-60c': Element image, 61: IP image

Claims

1. A spatial image display system that displays an object as a spatial image using IP technology, comprising: (a) an IP image converter that converts captured images obtained by photographing the object from multiple viewpoints into a group of elemental images, each consisting of multiple elemental images necessary for displaying the spatial image; and (b) a spatial image display unit that integrates an IP image panel having a display surface composed of multiple pixels arranged vertically and horizontally, and an IP filter having multiple light-transmitting parts positioned in front of the display surface of the IP image panel, wherein the IP image converter generates first to nth IP images composed of n different groups of elemental images that complement each other, and the spatial image display unit displays the first to nth IP images sequentially on the IP image panel in a time-division manner, and when the ith IP image is displayed, the light emitted from the ith IP image is transmitted through the light-transmitting parts located at the center of each of the multiple elemental images that constitute the ith IP image when viewed from the front. However, n is an integer of 2 or more, and i is an integer from 1 to n.

2. When n=2, the multiple element images on the first IP image and the multiple element images on the second IP image are arranged vertically and horizontally, each configured in a rectangular shape with vertical dimension a and horizontal dimension b when viewed from the front, by multiple pixels of the IP image panel, and the multiple light-transmitting parts are each formed in the shape of a pinhole and are grouped into a first light-transmitting group and a second light-transmitting group which are driven in a time-division manner, and the multiple light-transmitting parts of the first light-transmitting group have a vertical pitch P ａ = a, lateral pitch P ｂ The elements are arranged vertically and horizontally at =b, and the multiple light-transmitting parts of the second light-transmitting group have a vertical pitch P ａ = a, lateral pitch P ｂ The elements are arranged vertically and horizontally at =b, and the second light-transmitting group is positioned vertically relative to the first light-transmitting group P ａ / 2 and / or P in the lateral direction ｂ The spatial image display system according to claim 1, characterized in that the light-transmitting parts are arranged with a 2x offset, and only the plurality of light-transmitting parts included in the first light-transmitting group allow light emitted from the first IP image to pass through, and only the plurality of light-transmitting parts included in the second light-transmitting group allow light emitted from the second IP image to pass through.

3. When n=2, the plurality of element images on the first IP image and the plurality of element images on the second IP image each have a horizontal dimension W when viewed from the front by the plurality of pixels of the IP image panel, and are configured in a rectangular shape whose vertical dimension is equal to the vertical dimension of the display surface, arranged side by side in the horizontal direction. The light-transmitting portions are each formed in the shape of a vertically elongated slit, and are grouped into a first light-transmitting group and a second light-transmitting group which are driven in a time-division manner. The plurality of light-transmitting portions of the first light-transmitting group have a horizontal pitch P Ｗ =W, arranged side by side in the horizontal direction, and the plurality of light-transmitting portions of the second light-transmitting group have a horizontal pitch P Ｗ =W, arranged side by side in the horizontal direction, and the second light-transmitting group is shifted by P Ｗ / 2 in the horizontal direction relative to the first light-transmitting group. Only the plurality of light-transmitting portions included in the first light-transmitting group transmit light emitted from the first IP image, and only the plurality of light-transmitting portions included in the second light-transmitting group transmit light emitted from the second IP image. The aerial image display system according to claim 1, characterized in that:

4. When n=2, the first IP image is composed of a first region first IP image and a second region first IP image, the second IP image is composed of a first region second IP image and a second region second IP image, the first IP image is displayed such that the pixels constituting each of the multiple element images included in the first region first IP image and the pixels constituting each of the multiple element images included in the second region first IP image do not overlap, and the second IP image is displayed such that the pixels constituting each of the multiple element images included in the first region second IP image and the pixels constituting each of the multiple element images included in the second region second IP image do not overlap. The spatial image display system according to claim 1, characterized in that the spatial image display device comprises (a) a polarization unit that linearly polarizes light emitted from the first IP image of the first region and the second IP image of the first region in a first direction, and linearly polarizes light emitted from the first IP image of the second region and the second IP image of the second region in a second direction perpendicular to the first direction; (b) a first linear polarization filter provided corresponding to the light-transmitting portion located at the center of each of the plurality of element images included in each of the first IP image of the first region and the second IP image of the first region when viewed from the front, and which allows only light linearly polarized in the first direction to pass through; and (c) a second linear polarization filter provided corresponding to the light-transmitting portion located at the center of each of the plurality of element images included in each of the second IP image of the second region and the second IP image of the second region when viewed from the front, and which allows only light linearly polarized in the second direction to pass through.

5. The plurality of element images on the first IP image and the plurality of element images on the second IP image are each configured in a rectangular shape with vertical dimension a and horizontal dimension b when viewed from the front, using a plurality of pixels of the IP image panel, and are arranged vertically and horizontally, and the plurality of light-transmitting parts are each formed in the shape of a pinhole and are grouped into a first light-transmitting group and a second light-transmitting group which are driven in a time division, and the plurality of light-transmitting parts of the first light-transmitting group have a vertical pitch P ａ = a, lateral pitch P ｂ The multiple light-transmitting parts of the second light-transmitting group are arranged vertically and horizontally at a vertical pitch P = b / 2. ａ = a, lateral pitch P ｂ The second light-transmitting group is arranged vertically and horizontally at a ratio of = b / 2, and the second light-transmitting group is positioned vertically relative to the first light-transmitting group P ａ The spatial image display system according to claim 4, characterized in that the light-transmitting parts are arranged with a 2x offset, and only the plurality of light-transmitting parts included in the first light-transmitting group allow light emitted from the first IP image to pass through, and only the plurality of light-transmitting parts included in the second light-transmitting group allow light emitted from the second IP image to pass through.

6. The first linear polarizing filter and the second linear polarizing filter have a lateral pitch P ｂ The spatial image display system according to claim 5, characterized in that the stripes are arranged alternately in a vertical pattern at a rate of = b / 2.

7. When n=2, the first IP image is composed of a first region first IP image and a second region first IP image, the second IP image is composed of a first region second IP image and a second region second IP image, the first IP image is displayed such that the pixels constituting each of the multiple element images included in the first region first IP image and the pixels constituting each of the multiple element images included in the second region first IP image do not overlap, the second IP image is displayed such that the pixels constituting each of the multiple element images included in the first region second IP image and the pixels constituting each of the multiple element images included in the second region second IP image do not overlap, The spatial image display device comprises (a) a polarization unit that linearly polarizes light emitted from the first IP image of the first region and the second IP image of the first region in a first direction, and linearly polarizes light emitted from the first IP image of the second region and the second IP image of the second region in a second direction perpendicular to the first direction, and (b) a polarizer arranged on the light-emitting surface side of the IP filter and having a polarization axis parallel to the first direction. The IP filter functions as a first light-transmitting area in a region that overlaps with one or more pixels located at the center of each of the multiple element images included in the first IP image of the first region and one or more pixels located at the center of each of the multiple element images included in the second IP image of the first region when viewed from the front, allowing light linearly polarized in the first direction by the polarization unit and light linearly polarized in the second direction by the polarization unit to pass through as is; and functions as a second light-transmitting area in a region that overlaps with one or more pixels located at the center of each of the multiple element images included in the first IP image of the second region and one or more pixels located at the center of each of the multiple element images included in the second IP image of the second region when viewed from the front, allowing light linearly polarized in the first direction by the polarization unit to pass through after being linearly polarized in the second direction, and light linearly polarized in the second direction by the polarization unit to pass through after being linearly polarized in the first direction.

8. The spatial image display system according to claim 4 or 7, wherein the polarizing unit comprises a first polarizing alignment film, a second polarizing alignment film disposed opposite to the first polarizing alignment film, a polarizing liquid crystal layer made of liquid crystal filled between the first polarizing alignment film and the second polarizing alignment film, and a polarizing drive unit capable of switching the orientation direction of the liquid crystal molecules in the polarizing liquid crystal layer on a pixel-by-pixel basis, and the orientation processing direction of the first polarizing alignment film and the orientation processing direction of the second polarizing alignment film are orthogonal to each other.

9. The spatial image display system according to claim 7, wherein the IP filter comprises a first alignment film for shutters, a second alignment film for shutters positioned opposite the first alignment film for shutters, a liquid crystal layer for shutters made of liquid crystal filled between the first alignment film for shutters and the second alignment film for shutters in areas that function as at least the first and second light-transmitting portions, a shutter drive unit capable of switching the orientation direction of the liquid crystal molecules in the liquid crystal layer for shutters on a pixel-by-pixel basis, and a shielding portion that shields areas other than the areas that function as the first and second light-transmitting portions of the liquid crystal layer for shutters, wherein the orientation processing direction of the first alignment film for shutters and the orientation processing direction of the second alignment film for shutters are orthogonal to each other.

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