Aerial image display device, aerial image display method, and aerial image display program

Abstract

This aerial image display device (100) comprises: a display unit (110) that displays an image on a first side; a retroreflective unit (130) that is disposed on the first side of the display unit (110) and that creates a semi-transmissive retroreflective surface by means of the high-speed movement of a retroreflective material (131); and a reflection / transmission unit (140) that is disposed on a first side of the retroreflective unit (130), reflects a portion of incident light, and transmits a portion of the incident light.

Description

Aerial image display device, aerial image display method, and aerial image display program

[0001] The present invention relates to an aerial image display device, an aerial image display method, and an aerial image display program.

[0002] Aerial image display technology has been proposed that displays images in the air, making digital information appear as if it actually exists in real space.

[0003] In particular, a real image aerial imaging optical system using retroreflection with a retroreflector and a beam splitter has the advantage that it can be easily enlarged by tiling.

[0004] Motohiro Makiguchi, Ayaka Sano, Takahiro Matsumoto, Hiroshi Chigira, Takayoshi Mochiduki, "Implementation of Interactive Mirror-Transcending Aerial Imaging System," SUI '23, October 13-15, 2023, Sydney, NSW, Australia

[0005] On the other hand, a real aerial image optical system using retroreflective materials requires a beam splitter to be installed at an angle to the display, which serves as the light source. This requires the depth of the aerial image to be greater than the display width. Therefore, aerial image display devices using this method have the problem of being large in the depth direction.

[0006] The present invention has been made in light of the above circumstances, and an object of the present invention is to provide a technique for reducing the size of an aerial image display device in the depth direction.

[0007] One aspect of the present invention is an aerial image display device that includes a display unit that displays an image on a first side, a retroreflective unit that is disposed on the first side of the display unit and creates a semi-transparent retroreflective surface by high-speed movement of retroreflective material, and a reflective-transmissive unit that is disposed on the first side of the retroreflective unit and reflects a portion of incident light and transmits a portion of the light.

[0008] One aspect of the present invention is an aerial image display method, which displays an image on a first side, and creates a semi-transparent retroreflective surface on the first side of the image by moving a retroreflective material at high speed, which reflects part of incident light and transmits part of it on the first side of the retroreflective surface.

[0009] One aspect of the present invention is an aerial image display program that causes a computer to drive the display unit and the retroreflector.

[0010] According to the present invention, a technique for reducing the depth of an aerial image display device is provided.

[0011] FIG. 1 is a diagram showing the configuration of an aerial image display device according to a first embodiment. FIG. 2 is a diagram showing an example of the configuration of the retroreflector shown in FIG. 1. FIG. 3 is a diagram showing an example of the configuration of another retroreflector that can replace the retroreflector shown in FIG. 2. FIG. 4 is a diagram showing another example of the configuration of a retroreflector that can replace the retroreflector shown in FIG. 2. FIG. 5 is a diagram showing an example of the configuration in which the retroreflector shown in FIG. 1 is enlarged by tiling. FIG. 6 is a diagram showing the configuration of an aerial image display device according to a second embodiment. FIG. 7 is a diagram showing an example of the configuration of the display unit shown in FIG. 6. FIG. 8 is a diagram showing the configuration of an aerial image display device according to a third embodiment. FIG. 9 is a diagram showing an example of the configuration of the display / retroreflector shown in FIG. 8, viewed from the reflective / transmissive unit side. FIG. 10 is a diagram showing an example of the configuration of the display / retroreflector shown in FIG. 8, viewed from the retroreflector side. FIG. 11 is a diagram showing an example of the configuration in which the display / retroreflector shown in FIG. 8 is enlarged by tiling the display unit and retroreflector. FIG. 12 is a diagram showing the configuration of an aerial image display device according to a fourth embodiment. Fig. 13 is a diagram showing the configuration of an aerial image display device according to a fifth embodiment. Fig. 14 is a diagram showing the configuration of the display / retroreflection unit shown in Fig. 13. Fig. 15 is a diagram showing the configuration of an aerial image display device according to a sixth embodiment. Fig. 16 is a diagram showing the configuration of an aerial image display device according to a seventh embodiment. Fig. 17 is a diagram showing the configuration of an aerial image display device according to an eighth embodiment. Fig. 18 is a diagram showing the configuration of the display / retroreflection unit shown in Fig. 13. Fig. 19 is a diagram showing the configuration of a drive unit of the aerial image display device according to the embodiments.

[0012] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0013] (First embodiment) (Configuration) The configuration of an aerial image display device 100 according to the first embodiment will be described with reference to FIG. 1 . FIG. 1 is a diagram showing the configuration of the aerial image display device 100 according to the first embodiment, and is a side view taken along the optical axis of the aerial image display device 100. In the side view of FIG. 1 , the main components of the aerial image display device 100 are disposed on the left side of the page, and an aerial image AI is formed on the right side of the page. In the side view of FIG. 1 , for convenience in explaining the relative positional relationship, the right side of the page will be referred to as the first side, and the left side of the page will be referred to as the second side. This will also be applied to the other side views of FIG. 1 .

[0014] The first side is the side where the aerial image AI is formed, and can also be referred to as the side where the aerial image AI is viewed, and the second side is referred to as the side in the viewing direction.

[0015] The aerial image display device 100 according to the first embodiment has a display unit 110 , a polarization adjustment unit 120 , a retroreflection unit 130 , a reflection-transmission unit 140 , and a drive unit 10 .

[0016] The display unit 110 , polarization adjustment unit 120 , retroreflection unit 130 and reflection-transmission unit 140 are arranged parallel to one another and substantially perpendicular to the optical axis of the aerial image display device 100 .

[0017] The display unit 110 displays an image that is the source of the aerial image AI on the first side. The display unit 110 is a display, a monitor, or the like. For example, the display unit 110 is an LCD, an OLED, or the like. In order to impart binocular parallax to the aerial image AI itself, a naked-eye 3D monitor using a lenticular, a parallax barrier, or a microlens array may be used as the display unit 110.

[0018] The polarization adjuster 120 is disposed on a first side of the display unit 110. The polarization adjuster 120 converts light emitted from the display unit 110 to the first side into one-directional circularly polarized light, R-directional circularly polarized light, or L-directional circularly polarized light. In other words, R-directional circularly polarized light is clockwise circularly polarized light, and L-directional circularly polarized light is counterclockwise circularly polarized light. In the following description, the polarization adjuster 120 is assumed to convert light emitted from the display unit 110 into R-directional circularly polarized light.

[0019] For example, if the display unit 110 is an LCD that emits linearly polarized light, the polarization adjustment unit 120 is configured with a λ / 4 retardation film or a functional body equivalent thereto. Also, if the display unit 110 is an OLED or display that originally emits circularly polarized light in one direction, the polarization adjustment unit 120 may be omitted.

[0020] The retroreflective unit 130 is disposed on a first side of the display unit 110, or, if present, on a first side of the polarization adjustment unit 120. The retroreflective unit 130 creates a semi-transparent retroreflective surface on the first side. A semi-transparent retroreflective surface is a surface that retroreflects incident light from the first side and allows a view, object, etc. present on the back side (second side) to be seen through when observed with the naked eye from the first side.

[0021] 2 shows an example of the configuration of the retroreflection unit 130. The retroreflection unit 130 includes a retroreflection material 131 and a motor 136.

[0022] The retroreflective material 131 has a linear blade shape. The retroreflective material 131 retroreflects incident light on the first side surface back in the direction of incidence. That is, the retroreflective material 131 has a retroreflective surface on the first side.

[0023] The motor 136 is attached to the second side of the retroreflective material 131, i.e., the side opposite the retroreflective surface. The motor 136 is capable of rotating the retroreflective material 131 at high speed around an axis 132 that passes through the center of the retroreflective material 131. For example, the motor 136 is a stepping motor or the like.

[0024] By rotating the retroreflective material 131 at high speed using the motor 136, the first side surface of the retroreflective material 131 appears to the naked human eye as a semi-transparent retroreflective surface. In other words, the first side surface of the retroreflective material 131 retroreflects incident light, and objects and the like behind the retroreflective material 131, i.e., on the second side, are visible to the naked human eye.

[0025] The configuration example of the retroreflective unit 130 is not limited to the configuration shown in Fig. 2. Fig. 3 shows a configuration example of another retroreflective unit 150 that can replace the retroreflective unit 130 shown in Fig. 2. The retroreflective unit 150 shown in Fig. 3 has a retroreflective material 151 and a motor 156, similar to the retroreflective unit 130. However, unlike the retroreflective material 131, the retroreflective material 151 has a blade shape extending in a cross shape. Other functions of the retroreflective material 151 are similar to those of the retroreflective material 131. Similar to the motor 136, the motor 156 is capable of rotating the retroreflective material 151 at high speed around an axis 152 passing through the center of the retroreflective material 151.

[0026] FIG. 4 shows another example configuration of a retroreflective unit 160 that can replace the retroreflective unit 130 shown in FIG. 2 . Like the retroreflective unit 130, the retroreflective unit 160 shown in FIG. 4 includes a retroreflective material 161 and a motor 166. However, unlike the retroreflective material 131, the retroreflective material 161 has a circular shape with multiple (e.g., four) slits. Other functions of the retroreflective material 161 are the same as those of the retroreflective material 131. Like the motor 136, the motor 166 is capable of rotating the retroreflective material 161 at high speed around an axis 162 that passes through the center of the retroreflective material 161.

[0027] The retroreflective materials 131, 151, and 161 of these retroreflective units 130, 150, and 160 each have an area that transmits incident light from the second side when stationary, relative to the circular area that is traversed when rotated. Therefore, the retroreflective materials 131, 151, and 161 can create a semi-transparent retroreflective surface when rotated at high speed.

[0028] The area that transmits the incident light from the second side is an area that does not block the incident light, specifically, the area around the blades and the area of ​​the slits. Hereinafter, for convenience, the area that transmits the incident light from the second side will be referred to as the transmitting area.

[0029] 1 , the reflective-transmissive unit 140 is disposed on the first side of the retroreflective unit 130. The reflective-transmissive unit 140 is a so-called beam splitter, which reflects a portion of the incident light from the second side and transmits a portion of the incident light. The incident light from the second side includes light that has transmitted through the retroreflective unit 130 and light that has been retroreflected by the retroreflective unit 130.

[0030] The reflective / transmissive section 140 includes a transparent plate 141 , a retardation film 142 , and a reflective polarizing film 143 .

[0031] The transparent plate 141 is an optically transparent parallel plate having a pair of parallel flat surfaces. The transparent plate 141 is made of, for example, an acrylic plate or a glass plate. The transparent plate 141 does not affect the polarization of light passing through it.

[0032] The retardation film 142 is attached to the flat surface on the second side of the transparent plate 141. The retardation film 142 is a λ / 4 retardation film, and converts incident circularly polarized light into linearly polarized light.

[0033] The reflective polarizing film 143 is attached to the flat surface of the first side of the transparent plate 141. The reflective polarizing film 143 reflects a first linearly polarized light and transmits a second linearly polarized light perpendicular to the first linearly polarized light. The reflection axis of the reflective polarizing film 143 coincides with the vibration plane of the linearly polarized light converted from circularly polarized light in the R direction by the retardation film 142. In other words, the reflective polarizing film 143 is attached to the flat surface of the first side of the transparent plate 141 so as to satisfy these optical characteristic relationships.

[0034] Drive unit 10 drives and controls display unit 110, causing the image that is the basis of the aerial image to be displayed on display unit 110. Drive unit 10 also drives and controls motor 136 of retroreflection unit 130, causing retroreflection material 131 to rotate at high speed.

[0035] (Operation) In operation of the aerial image display device 100, the display unit 110 displays an image that is the source of the aerial image. Furthermore, the retroreflector 131 of the retroreflector 130 rotates at high speed to create a semi-transparent retroreflecting surface on the first side.

[0036] Light emitted from the display unit 110 enters the polarization adjustment unit 120, and as it travels through the polarization adjustment unit 120, some of the light is absorbed and some of the light becomes circularly polarized light in the R direction and exits the polarization adjustment unit 120. The R direction circularly polarized light that has exited the polarization adjustment unit 120 enters the retroreflection unit 130, and some of the R direction circularly polarized light passes through the transmission area of ​​the retroreflector 131 that rotates at high speed, and enters the reflection-transmission unit 140.

[0037] The circularly polarized light in the R direction that enters the reflection-transmission section 140 first enters the phase difference film 142, and as it passes through the phase difference film 142, it becomes s-polarized light relative to the reflective polarizing film 143, exits the phase difference film 142, passes through the transparent plate 141, and then enters the reflective polarizing film 143.

[0038] The s-polarized light incident on the reflective polarizing film 143 is reflected by the reflective polarizing film 143, passes through the transparent plate 141, and is incident on the retardation film 142. When the s-polarized light incident on the retardation film 142 passes through the retardation film 142, it becomes circularly polarized light in the R direction and exits the retardation film 142.

[0039] The R-direction circularly polarized light that has exited the retardation film 142 is incident on the semi-transparent retroreflective surface created by the retroreflective unit 130. A portion of the R-direction circularly polarized light is retroreflective by the retroreflective surface of the retroreflective unit 130 and becomes L-direction circularly polarized light.

[0040] The retroreflected circularly polarized light in the L direction enters the reflective-transmissive unit 140. The circularly polarized light in the L direction that entered the reflective-transmissive unit 140 first enters the retardation film 142, and while passing through the retardation film 142, becomes p-polarized light relative to the reflective polarizing film 143. The light exits the retardation film 142, passes through the transparent plate 141, and then enters the reflective polarizing film 143.

[0041] The p-polarized light incident on the reflective polarizing film 143 passes through the reflective polarizing film 143 and forms an aerial image AI at a projection distance D from the first side surface of the reflective / transmissive unit 140. The projection distance D is the distance d from the second side surface of the reflective polarizing film 143 of the reflective / transmissive unit 140, i.e., the s-polarized light reflecting surface, to the first side surface of the display unit 110, i.e., the light exit surface. ｄis equal to.

[0042] (Effect) In the aerial image display device 100 of this embodiment, by creating a semi-transparent retroreflective section using the retroreflective section 130, it is possible to arrange the display section 110, polarization adjustment section 120, retroreflective section 130, and reflective-transmissive section 140 parallel to each other and substantially perpendicular to the optical axis.

[0043] Therefore, the aerial image display device 100 according to the embodiment can be made significantly smaller in size in the depth direction than aerial image display devices using conventional techniques.

[0044] (Deformation / Expansion) The aerial image display device 100 according to this embodiment can be easily enlarged by tiling. An example of a configuration in which the retroreflector 130 is enlarged by tiling is shown in FIG. 5 . In FIG. 5 , a side view is depicted on the left, and a front view from the first side (viewing direction) is depicted on the right. As shown on the left side of FIG. 5 , the multiple retroreflectors 130 are appropriately offset in the optical axis direction (depth direction). Furthermore, as shown on the right side of FIG. 5 , the retroreflectors 130 are arranged so that, in a planar direction perpendicular to the optical axis, the circles of the orbits traced by the retroreflectors 131 due to rotation overlap without gaps when projected onto the planar surface. This allows the multiple retroreflectors 130 to cooperate with each other to create a large, semi-transparent retroreflecting surface.

[0045] In addition to enlarging the retroreflective section 130 in this manner, by enlarging the other elements, namely the display section 110, the polarization adjustment section 120, and the reflection / transmission section 140, either by enlarging the elements themselves or by tiling, the aerial image display device 100 becomes able to display a huge aerial image AI.

[0046] (Second embodiment) (Configuration) Next, the configuration of an aerial image display device 200 according to the second embodiment will be described with reference to Fig. 6. Fig. 6 is a diagram showing the configuration of the aerial image display device 200 according to the second embodiment. Fig. 6 is a side view corresponding to Fig. 1. In Fig. 6, components with the same reference numerals as those shown in Fig. 1 are similar components, and detailed description thereof will be omitted. The following description will focus on the differences. In other words, parts not mentioned in the following description are the same as those in the first embodiment.

[0047] The aerial image display device 200 according to the second embodiment has a first display unit 210, a second display unit 220, a polarization adjustment unit 230, a retroreflection unit 130, a reflection-transmission unit 140, and a drive unit 10.

[0048] The retroreflector 130 and the reflective-transmissive section 140 are the same optical elements as the retroreflector 130 and the reflective-transmissive section 140 of the first embodiment. In other words, the aerial image display device 200 of the second embodiment can be said to have a configuration in which the display section 110 and the polarization adjuster 120 of the aerial image display device 100 of the first embodiment are replaced with a first display section 210, a second display section 220, and a polarization adjuster 230.

[0049] The first display unit 210 produces, on a first side, a first semi-transparent image that is the basis of the first aerial image AI1. The second display unit 220 is disposed on the first side of the first display unit 210. The second display unit 220 produces, on the first side, a second semi-transparent image that is the basis of the second aerial image AI2.

[0050] A semi-transparent image is an image that is visible to the naked eye and allows the scenery, objects, etc. behind it to be seen through. For example, both the first display unit 210 and the second display unit 220 are configured with a versalite, a semi-transparent display, etc.

[0051] The first display unit 210 and the second display unit 220 have substantially the same structure. Here, a representative example of the configuration of the second display unit 220 using a Versalite will be described with reference to Fig. 7. Fig. 7 is a diagram showing the configuration of the second display unit 220, as seen from the polarization adjustment unit 230 side. The second display unit 220 has an LED bar 223 and a motor 226.

[0052] The LED bar 223 has a linearly extending elongated housing and a plurality of LEDs 224 arranged linearly along the longitudinal axis in the center of the housing. The plurality of LEDs 224 emits unpolarized light to a first side. The plurality of LEDs 224 may be, for example, a group of multicolored LEDs.

[0053] The motor 226 is attached to the second side of the LED bar 223, i.e., the side opposite to the light emitting surface. The motor 226 is capable of rotating the LED bar 223 at high speed around an axis passing through the center of the LED bar 223. For example, the motor 226 is a stepping motor or the like.

[0054] In the second display unit 220, i.e., the Versalite, the number of rotations of the motor 226, the position detection of each LED 224, and the on / off of each LED 224 are controlled by the drive unit 10. As a result, the second display unit 220, i.e., the Versalite, displays an image on the first side by illuminating the LEDs 224 at appropriate positions on the rotating LED bar 223.

[0055] The LED bar 223 has a transparent area that transmits incident light from the second side when stationary, in contrast to the circular area that it traverses when rotated. Specifically, the transparent area is an area surrounding the LED bar 223. Therefore, when observed with the naked eye from the first side, the naked eye can see an object behind the rotating LED bar 223, i.e., on the second side, such as the display image of the first display unit 210.

[0056] 6 , the polarization adjuster 230 is disposed on the first side of the second display unit 220. The retroreflector 130 is disposed on the first side of the polarization adjuster 230, and the reflective-transmissive unit 140 is disposed on the first side of the retroreflector 130.

[0057] The polarization adjustment unit 230 converts the unpolarized light emitted from the first display unit 210 and the second display unit 220 into circularly polarized light in one direction, in this case, circularly polarized light in the R direction. For example, the polarization adjustment unit 230 is made of an absorbing polarizing film.

[0058] (Operation) In operation of the aerial image display device 200, the first display unit 110 produces a first semi-transparent image on the first side, which is the basis for the aerial image AI1. The second display unit 220 produces a second semi-transparent image on the first side, which is the basis for the second aerial image AI2. The retroreflector 131 of the retroreflector 130 rotates at high speed, producing a semi-transparent retroreflecting surface on the first side.

[0059] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0060] A portion of the unpolarized light emitted from the first display unit 210 passes through the transmission area of ​​the second display unit 220, and then passes through the polarization adjustment unit 120, becoming circularly polarized light in the R direction, passing through the transmission area of ​​the retroreflective material 131, and entering the reflection-transmission unit 140.

[0061] The circularly polarized light in the R direction that enters the reflection-transmission section 140 becomes s-polarized light by passing through the phase difference film 142, and after being reflected by the reflective polarization film 143, it passes through the transparent plate 141 again to become circularly polarized light in the R direction again and enters the retroreflective section 130.

[0062] A portion of the R-direction circularly polarized light that enters retroreflective unit 130 is retroreflected by the retroreflective surface of retroreflective unit 130, becomes L-direction circularly polarized light, and enters reflective-transmissive unit 140. The L-direction circularly polarized light that enters reflective-transmissive unit 140 passes through retardation film 142 to become p-polarized light, transmits through reflective polarizing film 143, and exits reflective-transmissive unit 140, forming a first aerial image AI1 on the first side of reflective-transmissive unit 140.

[0063] A portion of the unpolarized light emitted from the second display unit 220 passes through the polarization adjustment unit 120, becomes circularly polarized light in the R direction, passes through the transmission area of ​​the retroreflective material 131, and enters the reflection-transmission unit 140.

[0064] The circularly polarized light in the R direction that enters the reflection-transmission section 140 becomes s-polarized light by passing through the phase difference film 142, and after being reflected by the reflective polarization film 143, it passes through the transparent plate 141 again to become circularly polarized light in the R direction again and enters the retroreflective section 130.

[0065] A portion of the R-direction circularly polarized light that enters retroreflection unit 130 is retroreflected by the retroreflective surface of retroreflection unit 130, becomes L-direction circularly polarized light, and enters reflection-transmission unit 140. The L-direction circularly polarized light that enters reflection-transmission unit 140 passes through phase difference film 142 to become p-polarized light, transmits through reflective polarization film 143, and exits reflection-transmission unit 140, forming a second aerial image AI2 on the first side of reflection-transmission unit 140.

[0066] The aerial image display device 200 according to the second embodiment has, as its display units, a first display unit 210 and a second display unit 220 that produce semi-transparent images, and is therefore capable of forming a first aerial image AI1 and a second aerial image AI2. That is, the aerial image display device 200 can form two layers of the first aerial image AI1 and the second aerial image AI2. In other words, the aerial image display device 200 can create a multi-layered aerial image.

[0067] The projection distance of the first aerial image AI1, i.e., the distance from the first side surface of the reflective / transmissive unit 140 to the first aerial image AI1, is equal to the distance from the second side surface of the reflective / transmissive unit 140 to the first side surface of the first display unit 210. Furthermore, the projection distance of the second aerial image AI2, i.e., the distance from the first side surface of the reflective / transmissive unit 140 to the second aerial image AI2, is equal to the distance from the second side surface of the reflective / transmissive unit 140 to the first side surface of the second display unit 220.

[0068] In the aerial image display device 200 according to this embodiment, the first display unit 210 and the second display unit 220 have substantially the same structure, but the first display unit 210 may be a device that produces a normal image rather than a device that produces a semi-transparent image, that is, for example, a display such as an LCD or OLED, a monitor, etc., as in the first embodiment. Even with such a configuration, the aerial image display device 200 can form a two-layer first aerial image AI1 and a second aerial image AI2.

[0069] Furthermore, the aerial image display device 200 may further include, for example, a display unit that produces a semi-transparent image similar to the second display unit 220, on the first side of the second display unit 220. With such a configuration, the aerial image display device 200 can form three or more layers of aerial images.

[0070] (Effects) In the aerial image display device 200 according to this embodiment, the first display unit 210, the second display unit 220, the polarization adjustment unit 230, the retroreflection unit 130, and the reflection-transmission unit 140 are arranged in parallel, and therefore, similar to the aerial image display device 100 according to the first embodiment, it can be significantly smaller in size in the depth direction than aerial image display devices using conventional methods. In addition, the aerial image display device 200 according to this embodiment can display aerial images in multiple layers.

[0071] (Third embodiment) (Configuration) Next, the configuration of an aerial image display device 300 according to the third embodiment will be described with reference to Fig. 8. Fig. 8 is a diagram showing the configuration of an aerial image display device 300 according to the third embodiment. Fig. 8 is a side view corresponding to Fig. 1. In Fig. 8, components with the same reference numerals as those shown in Fig. 1 are similar components, and detailed description thereof will be omitted. The following description will focus on differences. In other words, parts not mentioned in the following description are the same as those in the first embodiment.

[0072] The aerial image display device 300 according to the third embodiment has a display / retroreflection unit 310 , a reflection unit 320 , a reflection / transmission unit 140 , and a drive unit 10 .

[0073] The reflective-transmissive section 140 is the same optical element as the reflective-transmissive section 140 of the first embodiment. In other words, the aerial image display device 300 of the third embodiment can be said to have a configuration in which the display section 110, polarization adjustment section 120, and retroreflection section 130 of the aerial image display device 100 of the first embodiment are replaced with a display / retroreflection section 310, and a reflection section 320 is added.

[0074] That is, the display / retroreflection unit 310, the reflection unit 320, and the reflection-transmission unit 140 are arranged parallel to one another and substantially perpendicular to the optical axis of the aerial image display device 300. The display / retroreflection unit 310 is arranged on a first side of the reflection unit 320. The reflection-transmission unit 140 is arranged on the first side of the display / retroreflection unit 310.

[0075] The display / retroreflection unit 310 produces a semi-transparent retroreflective surface on the first side, similar to the retroreflection unit 130 of the first embodiment. In addition, the display / retroreflection unit 310 produces a semi-transparent image on the second side, which is the basis of the aerial image AI.

[0076] The reflecting unit 320 is disposed on the second side of the display / retroreflecting unit 310. The reflecting unit 320 has a reflective surface on the first side. The reflecting unit 320 reflects incident light from the second side that is emitted from the display / retroreflecting unit 310 back to the first side. The reflecting unit 320 is preferably a highly reflective mirror, a completely reflective mirror, or the like.

[0077] In terms of function, the display / retroreflection unit 310 can be said to be a combination of the retroreflection unit 130 of the first embodiment and, for example, the second display unit 220 of the second embodiment.

[0078] An example of the configuration of the display / retroreflection unit 310 will be described with reference to Fig. 9 and Fig. 10. Fig. 9 and Fig. 10 are diagrams showing an example of the configuration of the display / retroreflection unit 310. Fig. 9 is a front view of the display / retroreflection unit 310 as seen from a first side, for example, the side of the reflective / transmissive unit 140. Fig. 10 is a front view of the display / retroreflection unit 310 as seen from a second side, for example, the side of the reflective unit 320.

[0079] The display / retroreflection unit 310 includes a retroreflector 311 , an LED bar 313 , a polarization adjustment unit 315 , and a motor 316 .

[0080] The retroreflective material 311 has a linear blade shape, for example, an elongated plate shape, similar to the retroreflective material 131. The retroreflective material 311 has a retroreflective surface on a first side.

[0081] Like the LED bar 223, the LED bar 313 has a long, narrow housing that extends linearly, and has a plurality of LEDs 314 that are arranged linearly along the longitudinal axis in the center of the housing. The plurality of LEDs 314 emit unpolarized light to the second side. The plurality of LEDs 314 is, for example, a group of multi-colored LEDs. A mechanism for suppressing the spread of light, such as a viewing angle limiting film or louver, may be provided on the light exit surface of the LED bar 313.

[0082] The retroreflective material 311 and the LED bar 313 are laminated together with their retroreflective surfaces facing the first side and their light-emitting surfaces facing the second side.

[0083] The polarization adjuster 315 is attached to the second surface, i.e., the light output surface, of the LED bar 313. The polarization adjuster 315 converts the unpolarized light output from the LEDs 314 into circularly polarized light in one direction, in this case, circularly polarized light in the L direction. For example, the polarization adjuster 315 is made of an absorbing polarizing film or the like.

[0084] The motor 316 is attached to a first side of the retroreflector 131, i.e., the side of the retroreflector surface. The motor 316 is capable of rotating the laminated structure of the retroreflector 311, the LED bar 313, and the polarization adjuster 315 at high speed around an axis passing through the center of the laminated structure. For example, the motor 316 is a stepping motor or the like.

[0085] In the display / retroreflection unit 310, the number of rotations of the motor 316, the position detection of each LED 314, and the on / off of each LED 314 are controlled by the drive unit 10. As a result, the display / retroreflection unit 310 creates a semi-transparent retroreflective surface on the first side, and also creates a semi-transparent image that serves as the source of the aerial image AI on the second side.

[0086] (Operation) In operation of the aerial image display device 300, the display / retroreflection unit 310 has a laminated structure of retroreflector 311, LED bar 313, and polarization adjustment unit 315 that rotates at high speed to create a semi-transparent image that is the source of the aerial image AI on the second side, and also creates a semi-transparent retroreflection surface on the first side.

[0087] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0088] A portion of the unpolarized light emitted from the LED bar 313 passes through the polarization adjustment unit 315, becomes circularly polarized light in the L direction, and enters the reflecting unit 320. The L direction circularly polarized light that entered the reflecting unit 320 is reflected by the reflecting unit 320, becomes circularly polarized light in the R direction, and enters the display / retroreflection unit 310. A portion of the R direction circularly polarized light that entered the display / retroreflection unit 310 passes through the transmission area and enters the reflection / transmission unit 140.

[0089] The circularly polarized light in the R direction that enters the reflection / transmission section 140 becomes s-polarized light by passing through the phase difference film 142, and after being reflected by the reflective polarization film 143, it passes through the transparent plate 141 again to become circularly polarized light in the R direction again and enters the display / retroreflection section 310.

[0090] A portion of the R-direction circularly polarized light that is incident on display / retroreflection unit 310 is retroreflected by the retroreflective surface of display / retroreflection unit 310, becomes L-direction circularly polarized light, and enters reflective-transmission unit 140. The L-direction circularly polarized light that is incident on reflective-transmission unit 140 passes through retardation film 142 to become p-polarized light, transmits through reflective polarization film 143, exits reflective-transmission unit 140, and forms an aerial image AI on the first side of reflective-transmission unit 140.

[0091] (Effect) In the aerial image display device 300 of this embodiment, the reflective section 320, the display / retroreflective section 310, and the reflective / transmissive section 140 are arranged in parallel, and therefore, similar to the aerial image display device 100 of the first embodiment, it can be significantly smaller in the depth direction compared to aerial image display devices using conventional methods.

[0092] In the aerial image display device 300 according to this embodiment, the projection distance D of the aerial image AI (the distance from the first side surface of the reflective / transmissive unit 140 to the aerial image AI) is defined as the distance from the second side surface of the LED bar 313, i.e., the light exit surface, to the first side surface of the reflector 320, i.e., the reflecting surface, defined as d ｍ, the distance from the second side surface of the LED bar 313, i.e., the light output surface, to the second side surface of the reflective polarizing film 143, i.e., the s-polarized light reflecting surface, is defined as d ｒ Then, 2d ｍ +d ｒ is.

[0093] When the projection distance D of the aerial image AI is set equal in the aerial image display device 300 according to this embodiment and the aerial image display device 100 according to the first embodiment, the projection distance D in the aerial image display device 100 is set equal to d ｄ and the projection distance D in the aerial image display device 300 is D=2d ｍ +d ｒ Therefore, d ｄ = 2d ｍ +d ｒ The following relationship is obtained.

[0094] For convenience, the depth distance of the aerial image display devices 100 and 300 is considered to be the distance from the first side surface of the rearmost (leftmost) optical element to the second side surface of the frontmost (rightmost) optical element. In this case, the depth distance of the aerial image display device 100 is the distance from the first side surface of the display unit 110, i.e., the light exit surface, to the second side surface of the reflective polarizing film 143, i.e., the s-polarized light reflecting surface, and is equal to dd. The depth distance of the aerial image display device 300 is the distance from the first side surface of the reflector 320, i.e., the reflecting surface, to the second side surface of the reflective polarizing film 143, i.e., the s-polarized light reflecting surface, and is equal to d. ｍ +d ｒ is equal to.

[0095] The aforementioned relationship d ｄ = 2d ｍ +d ｒ From, d ｍ +d ｒ <d ｄ That is, when the depth distances of the aerial image display devices 100 and 300 are compared under the common condition that the projection distances D of the aerial images AI are equal to each other, the depth distance of the aerial image display device 300 according to this embodiment is smaller than that of the aerial image display device 100 according to the first embodiment. That is, the aerial image display device 300 is smaller in the depth direction than the aerial image display device 100.

[0096] (Modifications and Extensions) In the aerial image display device 300 according to this embodiment, the retroreflector 311, LED bars 313, and polarization adjuster 315 of the display / retroreflector 310 are integrated together. The optical function of the retroreflector 311 and the optical functions of the LED bars 313 and polarization adjuster 315 can be considered separate entities. For this reason, the display / retroreflector 310 can also be divided into an optical function unit of the retroreflector 311 and an optical function unit of the LED bars 313 and polarization adjuster 315.

[0097] 11 , an example of a configuration in which the display / retroreflecting unit 310 is divided into an optical function unit of the retroreflector 311 and an optical function unit of the LED bar 313 and polarization adjustment unit 315 will be described. For convenience, the optical function unit of the retroreflector 311 will be referred to as the retroreflecting unit 330, and the optical function unit of the LED bar 313 and polarization adjustment unit 315 will be referred to as the display unit 340.

[0098] Furthermore, the retroreflective unit 330 and the display unit 340 can be easily enlarged by tiling, similar to the retroreflective unit 130 described with reference to Fig. 5. Fig. 11 shows an example of a configuration in which the retroreflective unit 330 and the display unit 340 are enlarged by tiling.

[0099] Here, the retroreflective unit 330 can be said to have a configuration in which the LED bar 313 and the polarization adjustment unit 315 are omitted from the display / retroreflective unit 310. Also, the display unit 340 can be said to have a configuration in which the retroreflective material 311 is omitted from the display / retroreflective unit 310. The components and functions of the retroreflective unit 330 and the display unit 340 can be easily inferred from the description of the display / retroreflective unit 310, so in Figure 11, the reference numerals of the components of the display / retroreflective unit 310 are used to indicate them, and a description of their components and functions will be omitted.

[0100] Additionally, the retroreflection unit 330 has a retroreflection material 311 and a motor 316 that rotates it. The display unit 340 has a laminated structure of an LED bar 313 and a polarization adjustment unit 315, and a motor 316 that rotates it.

[0101] 11, as in FIG. 5, a side view is depicted on the left side, and a front view seen from the first side (viewing direction) is depicted on the right side. As shown on the left side of FIG. 11, the retroreflective unit 330 and the display unit 340 are appropriately offset in the optical axis direction (depth direction). Also, as shown on the right side of FIG. 11, in the planar direction perpendicular to the optical axis, the retroreflective unit 131 and the orbital circle drawn by the rotation thereof overlap without any gaps with the orbital circle drawn by the rotation of the laminated structure of the LED bar 313 and polarization adjustment unit 315. In this way, the multiple retroreflective units 330 and the display units 340 can cooperate with each other to create a huge semi-transparent retroreflective surface and a display image.

[0102] In this configuration, from the viewpoint of placing importance on the formation of a display image, it is preferable to set the number of display units 340 to be greater than the number of retroreflecting units 330. Furthermore, from the viewpoint of placing importance on the formation of an aerial image, it is preferable to set the rotation speed of retroreflecting units 330 to be higher than the rotation speed of display units 340.

[0103] (Fourth embodiment) (Configuration) Next, the configuration of an aerial image display device 400 according to the fourth embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram showing the configuration of the aerial image display device 400 according to the fourth embodiment. Fig. 12 is a side view corresponding to Fig. 8. In Fig. 12, components with the same reference numerals as those shown in Fig. 8 are similar components, and detailed description thereof will be omitted. The following description will focus on the differences. In other words, parts not mentioned in the following description are the same as those in the third embodiment.

[0104] The aerial image display device 400 according to the fourth embodiment has a display / retroreflection unit 310 , a display unit 410 , a reflection unit 320 , a reflection / transmission unit 140 , and a drive unit 10 .

[0105] The aerial image display device 400 of the fourth embodiment is configured by adding a display unit 410 between the display / retroreflection unit 310 and the reflection unit 320 to the aerial image display device 300 of the third embodiment.

[0106] That is, the display / retroreflection unit 310, the display unit 410, the reflection unit 320, and the reflection-transmission unit 140 are arranged parallel to one another and substantially perpendicular to the optical axis of the aerial image display device 400. The display unit 410 is arranged on a first side of the reflection unit 320. The display / retroreflection unit 310 is arranged on a first side of the display unit 410. The reflection-transmission unit 140 is arranged on the first side of the display / retroreflection unit 310.

[0107] The display unit 410 has the same structure as the display unit 340 described above. That is, the display unit 410 can be said to have a configuration in which the retroreflective material 311 is omitted from the display / retroreflective unit 310. In other words, the display unit 410 has a laminated structure of an LED bar 413 and a polarization adjustment unit 415, and a motor 416 that rotates the laminated structure of the LED bar 413 and the polarization adjustment unit 415.

[0108] The functional configuration of the LED bar 413 is similar to that of the LED bar 313 of the display / retroreflection unit 310. The functional configuration of the polarization adjustment unit 415 is similar to that of the polarization adjustment unit 315 of the display / retroreflection unit 310. The motor 416 is similar to the motor 316 of the display / retroreflection unit 310.

[0109] The display / retroreflection unit 310 creates a semi-transparent retroreflective surface on the first side, and also creates a semi-transparent image on the second side that serves as the basis for the first aerial image AI1.

[0110] The display unit 410 creates a semi-transparent image on the second side that is the basis of the second aerial image AI2.

[0111] The reflecting unit 320 is disposed on the second side of the display unit 410. The reflecting unit 320 has a reflective surface on the first side. The reflecting unit 320 reflects incident light from the second side, which is emitted from the display / retroreflecting unit 310 and the display unit 410, back to the first side. The reflecting unit 320 is preferably a highly reflective mirror, a completely reflective mirror, or the like.

[0112] (Operation) In operation of aerial image display device 400, display / retroreflection unit 310 has a laminated structure of retroreflector 311, LED bars 313, and polarization adjuster 315 that rotates at high speed to produce a semi-transparent image that is the basis of first aerial image AI1 on the second side and a semi-transparent retroreflective surface on the first side. Furthermore, display unit 410 has a laminated structure of LED bars 313 and polarization adjuster 315 that rotates at high speed to produce a semi-transparent image that is the basis of second aerial image AI2 on the second side.

[0113] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0114] A portion of the unpolarized light emitted from the LED bars 313 of the display / retroreflection unit 310 passes through the polarization adjustment unit 315 and becomes circularly polarized light in the L direction. The light then passes through the transmissive area of ​​the display unit 410 and enters the reflective unit 320. The L direction circularly polarized light that entered the reflective unit 320 is reflected by the reflective unit 320 and becomes circularly polarized light in the R direction. The R direction circularly polarized light that was reflected by the reflective unit 320 passes through the transmissive area of ​​the display unit 410, then passes through the transmissive area of ​​the display / retroreflection unit 310, and enters the reflective / transmissive unit 140.

[0115] The R-direction circularly polarized light that enters reflective-transmissive unit 140 is reflected by reflective-transmissive unit 140 and enters display / retroreflective unit 310. A portion of the R-direction circularly polarized light that enters display / retroreflective unit 310 is retroreflected by the retroreflective surface of display / retroreflective unit 310, becomes L-direction circularly polarized light, transmits through reflective-transmissive unit 140, and forms a first aerial image AI on a first side of reflective-transmissive unit 140.

[0116] A portion of the unpolarized light emitted from the LED bars 413 of the display unit 410 passes through the polarization adjustment unit 415, becomes circularly polarized light in the L direction, and enters the reflecting unit 320. The L direction circularly polarized light that entered the reflecting unit 320 is reflected by the reflecting unit 320 and becomes circularly polarized light in the R direction. A portion of the R direction circularly polarized light reflected by the reflecting unit 320 passes through the transmissive area of ​​the display unit 410, then passes through the transmissive area of ​​the display / retroreflecting unit 310, and enters the reflective / transmissive unit 140.

[0117] The R-direction circularly polarized light that enters reflective-transmissive unit 140 is reflected by reflective-transmissive unit 140 and enters display / retroreflective unit 310. A portion of the R-direction circularly polarized light that enters display / retroreflective unit 310 is retroreflected by the retroreflective surface of display / retroreflective unit 310, becomes L-direction circularly polarized light, and transmits through reflective-transmissive unit 140 to form a second aerial image AI2 on the first side of reflective-transmissive unit 140.

[0118] The projection distance D of the first aerial image AI is defined as the distance from the second side surface of LED bar 313, i.e., the light emitting surface, to the first side surface of reflecting portion 320, i.e., the reflecting surface, defined as d ｍ１ , the distance from the second side surface of the LED bar 313, i.e., the light output surface, to the second side surface of the reflective polarizing film 143, i.e., the s-polarized light reflecting surface, is defined as d ｒ２ Then, 2d ｍ１ +d ｒ１ is.

[0119] The projection distance D of the second aerial image AI is defined as the distance from the second side surface of the LED bar 413, i.e., the light emitting surface, to the first side surface of the reflecting portion 320, i.e., the reflecting surface, defined as d ｍ２ , the distance from the second side surface of the LED bar 413, i.e., the light output surface, to the second side surface of the reflective polarizing film 143, i.e., the s-polarized light reflecting surface, is defined as d ｒ２ Then, 2d ｍ２ +d ｒ２ is.

[0120] (Effect) In the aerial image display device 400 of this embodiment, the reflecting section 320, the display section 410, the display / retroreflecting section 310, and the reflective / transmissive section 140 are arranged in parallel, so similar to the aerial image display device 100 of the first embodiment, it can be made significantly smaller in the depth direction compared to aerial image display devices using conventional methods.

[0121] (Fifth Embodiment) (Configuration) Next, the configuration of an aerial image display device 500 according to the fifth embodiment will be described with reference to Fig. 13. Fig. 13 is a diagram showing the configuration of the aerial image display device 500 according to the fifth embodiment. Fig. 13 is a side view corresponding to Fig. 1. In Fig. 13, components with the same reference numerals as those shown in Fig. 1 are similar components, and detailed description thereof will be omitted. The following description will focus on differences. In other words, parts not mentioned in the following description are the same as those in the first embodiment.

[0122] The aerial image display device 500 according to the fifth embodiment has a display / retroreflection unit 510, a reflection / transmission unit 140, and a drive unit 10.

[0123] The aerial image display device 500 of the fifth embodiment can be said to have a configuration in which the display unit 110, polarization adjustment unit 120, and retroreflection unit 130 of the aerial image display device 100 of the first embodiment are replaced with a display / retroreflection unit 510.

[0124] The display / retroreflection unit 510 and the reflective / transmissive unit 140 are arranged parallel to each other and substantially perpendicular to the optical axis of the aerial image display device 500. The display / retroreflection unit 510 is arranged on the second side of the reflective / transmissive unit 140. The reflective / transmissive unit 140 is arranged on the first side of the display / retroreflection unit 510.

[0125] The display / retroreflection unit 510 creates a semi-transparent retroreflection surface on the first side, and also creates a semi-transparent image on the first side that serves as the basis for the aerial image AI.

[0126] In terms of function, the display / retroreflection unit 510 can be said to be a combination of the retroreflection unit 130 of the first embodiment and, for example, the second display unit 220 of the second embodiment.

[0127] An example of the configuration of the display / retroreflection unit 510 will be described with reference to Fig. 14. Fig. 14 is a diagram showing an example of the configuration of the display / retroreflection unit 510, and is a front view of the display / retroreflection unit 510 as seen from a first side, for example, the side of the reflective / transmissive unit 140.

[0128] The display / retroreflection unit 510 has a pair of retroreflectors 511 , an LED bar 513 , a polarization adjustment unit 515 , and a motor 516 .

[0129] Each retroreflective element 511 has a linear blade shape, for example, an elongated plate shape, similar to the retroreflective element 131. The retroreflective element 511 has a retroreflective surface on a first side.

[0130] Like the LED bar 223, the LED bar 513 has a long, narrow housing that extends linearly, and has a plurality of LEDs 314 that are arranged linearly along the longitudinal axis in the center of the housing. The plurality of LEDs 314 emit unpolarized light to a first side. The plurality of LEDs 314 is, for example, a group of multi-colored LEDs. The light exit surface of the LED bar 513 may be provided with a mechanism for suppressing the spread of light, such as a viewing angle limiting film or louver.

[0131] The polarization adjuster 515 is attached to the light emission surface of the LED bar 513. The polarization adjuster 515 converts the unpolarized light emitted from the LEDs 314 into circularly polarized light in one direction, in this case, circularly polarized light in the R direction. For example, the polarization adjuster 515 is made of an absorbing polarizing film or the like.

[0132] The pair of retroreflectors 511 are arranged adjacent to and bonded to both sides of the LED bar 513. The retroreflecting surface of the retroreflector 511 and the light-emitting surface of the LED bar 513 face the same side.

[0133] The motor 516 is attached to a second side of the retroreflector 511 and the LED bar 513, i.e., the side opposite the retroreflecting surface and the light emitting surface. The motor 516 is capable of rotating the laminated structure at high speed around an axis passing through the center of the integrated structure of the retroreflector 511, the LED bar 513, and the polarization adjuster 515. For example, the motor 516 is a stepping motor or the like.

[0134] In the display / retroreflection unit 510, the number of rotations of the motor 516, the position detection of each LED 314, and the on / off of each LED 314 are controlled by the drive unit 10. As a result, the display / retroreflection unit 510 creates, on the first side, a semi-transparent retroreflective surface and a semi-transparent image that is the source of the aerial image AI.

[0135] (Operation) In operation of the aerial image display device 500, the display / retroreflection unit 510 has a laminated structure of retroreflector 511, LED bar 513, and polarization adjustment unit 515 that rotates at high speed, creating a semi-transparent image that is the source of the aerial image AI and a semi-transparent retroreflection surface on the first side.

[0136] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0137] A portion of the unpolarized light emitted from the LED bar 513 passes through the polarization adjustment unit 515 and becomes circularly polarized light in the R direction, and enters the reflective / transmissive unit 140. The R-direction circularly polarized light that entered the reflective / transmissive unit 140 is reflected by the reflective / transmissive unit 140 and enters the display / retroreflective unit 510. A portion of the R-direction circularly polarized light that entered the display / retroreflective unit 510 is retroreflected by the retroreflecting surface created by the display / retroreflective unit 510, becomes circularly polarized light in the L direction, passes through the reflective / retroreflective unit 140, and forms an aerial image AI on the first side of the reflective / retroreflective unit 140. The projection distance D is the distance d from the second side surface of the reflective polarizing film 143, i.e., the s-polarized reflecting surface, to the first side surface of the display unit 110, i.e., the light exit surface. ｄ is equal to.

[0138] (Effects) In the aerial image display device 500 according to this embodiment, the display / retroreflection unit 510 and the reflective / transmissive unit 140 are arranged in parallel, and therefore, similar to the aerial image display device 100 according to the first embodiment, it can be significantly smaller in size in the depth direction than aerial image display devices using conventional methods. Furthermore, since the only optical elements that the aerial image display device 500 has are the display / retroreflection unit 510 and the reflective / transmissive unit 140, the aerial image display device 500 can be configured to be extremely small in size in the depth direction.

[0139] (Sixth embodiment) (Configuration) Next, the configuration of an aerial image display device 600 according to the sixth embodiment will be described with reference to Fig. 15. Fig. 15 is a diagram showing the configuration of the aerial image display device 600 according to the sixth embodiment. Fig. 15 is a side view corresponding to Fig. 1. In Fig. 15, components with the same reference numerals as those shown in Fig. 1 are similar components, and detailed description thereof will be omitted. The following description will focus on differences. In other words, parts not mentioned in the following description are the same as those in the first embodiment.

[0140] The aerial image display device 600 according to the sixth embodiment has a display unit 110 , a polarization adjustment unit 610 , a retroreflection unit 130 , a reflection-transmission unit 140 , and a drive unit 10 .

[0141] The polarization adjustment unit 610 is disposed on a first side of the display unit 110. The retroreflective unit 130 is disposed on the first side of the polarization adjustment unit 610. The reflective-transmissive unit 140 is disposed on the first side of the retroreflective unit 130. The polarization adjustment unit 610 is disposed on the first side of the display unit 110.

[0142] That is, the aerial image display device 600 according to the sixth embodiment can be said to have a configuration in which the polarization adjustment section 120 of the aerial image display device 100 according to the first embodiment is replaced with a polarization adjustment section 610 .

[0143] The polarization adjustment unit 120 in the aerial image display device 100 of the first embodiment is an optical element that converts the light emitted from the display unit 110 to the first side into circularly polarized light in one direction, circularly polarized light in the R direction, or circularly polarized light in the L direction.

[0144] In contrast, the polarization adjuster 610 in the aerial image display device 600 according to this embodiment is an optical element that converts the light emitted from the display unit 110 to the first side into two-directional circularly polarized light, that is, circularly polarized light in the R direction and circularly polarized light in the L direction. For example, the polarization adjuster 610 is made of an absorbing polarizing film.

[0145] (Operation) In operation of the aerial image display device 600, the display unit 110 displays an image that is the source of the aerial image. The retroreflector 131 of the retroreflector 130 rotates at high speed to create a semi-transparent retroreflecting surface on the first side.

[0146] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0147] A portion of the unpolarized light emitted from the display unit 110 passes through the polarization adjustment unit 610 and becomes circularly polarized light in the R direction. The light passes through the transmission area of ​​the retroreflective material 131 and enters the reflective-transmissive unit 140. The R-direction circularly polarized light that entered the reflective-transmissive unit 140 is reflected by the reflective-transmissive unit 140 and enters the retroreflective unit 130. A portion of the R-direction circularly polarized light that entered the retroreflective unit 130 is retroreflected by the retroreflective surface of the retroreflective unit 130 and becomes circularly polarized light in the L direction, which then enters the reflective-transmissive unit 140. The L-direction circularly polarized light that entered the reflective-transmissive unit 140 passes through the reflective-transmissive unit 140 and forms an aerial image AI on the first side of the reflective-transmissive unit 140.

[0148] Furthermore, another portion of the unpolarized light emitted from display unit 110 becomes circularly polarized light in the L direction by passing through polarization adjustment unit 610, passes through the transmission area of ​​retroreflector 131, and enters reflection-transmission unit 140. The L-direction circularly polarized light that has entered reflection-transmission unit 140 is transmitted through reflection-transmission unit 140 and is emitted to the first side of reflection-transmission unit 140. This emitted light is not retroreflected by retroreflection unit 130, and therefore does not contribute to the formation of aerial image AI.

[0149] A viewer of the aerial image display device 600 views the aerial image display device 600 from the first side of the aerial image AI. At this time, the viewer can see the aerial image AI. The reflective / transmissive unit 140 and the retroreflective unit 130 are semi-transparent and transmit a portion of the circularly polarized light in the L direction from the polarization adjustment unit 610. Therefore, the viewer can see the image displayed on the display unit 110 in addition to the aerial image AI.

[0150] (Effects) The aerial image display device 600 according to this embodiment can be significantly smaller in size in the depth direction than aerial image display devices using conventional methods, similar to the aerial image display device 100 according to the first embodiment. In addition, the aerial image display device 600 according to this embodiment can show the viewer the display image on the display unit 110 in addition to the aerial image.

[0151] (Seventh embodiment) (Configuration) Next, the configuration of an aerial image display device 700 according to the seventh embodiment will be described with reference to Fig. 16. Fig. 16 is a diagram showing the configuration of the aerial image display device 700 according to the seventh embodiment. Fig. 16 is a side view corresponding to Fig. 12. In Fig. 16, components with the same reference numerals as those shown in Fig. 12 are similar components, and detailed description thereof will be omitted. The following description will focus on the differences. In other words, parts not mentioned in the following description are the same as those in the fourth embodiment.

[0152] The aerial image display device 700 according to the seventh embodiment has a display / retroreflection unit 310 , a display unit 710 , a reflection unit 320 , a reflection / transmission unit 140 , and a drive unit 10 .

[0153] The display / retroreflection unit 310, the display unit 710, the reflection unit 320, and the reflection-transmission unit 140 are arranged parallel to one another and substantially perpendicular to the optical axis of the aerial image display device 700. The display unit 710 is arranged on a first side of the reflection unit 320. The display / retroreflection unit 310 is arranged on a first side of the display unit 710. The reflection-transmission unit 140 is arranged on the first side of the display / retroreflection unit 310.

[0154] That is, the aerial image display device 700 according to the seventh embodiment can be said to have a configuration in which the display unit 410 of the aerial image display device 400 according to the fourth embodiment is replaced with the display unit 710 .

[0155] The display unit 410 has the same structure as the display unit 340 described above. That is, the display unit 410 can be said to have a configuration in which the retroreflective material 311 is omitted from the display / retroreflective unit 310. In other words, the display unit 410 has a laminated structure of an LED bar 413 and a polarization adjustment unit 415, and a motor 416 that rotates the laminated structure of the LED bar 413 and the polarization adjustment unit 415.

[0156] The display unit 710, like the display unit 410 of the aerial image display device 400 according to the fourth embodiment, produces a second semi-transparent image on the first side, which is the source of the second aerial image AI2. In addition, the display unit 710 produces a third semi-transparent image on the second side.

[0157] The display unit 710 has a first LED bar 713 , a first polarization adjustment unit 715 , a second LED bar 723 , a second polarization adjustment unit 725 , and a motor 736 .

[0158] The first LED bar 713 and the second LED bar 723 each have a structure similar to, for example, the LED bar 413 of the display unit 410 of the aerial image display device 400 according to the fourth embodiment. That is, the first LED bar 713 and the second LED bar 723 each have a linearly extending, elongated housing and a plurality of LEDs arranged linearly along the longitudinal axis in the center of the housing. The plurality of LEDs is, for example, a group of multicolored LEDs. The light-emitting surface of the LED bar may be provided with a mechanism for suppressing the spread of light, such as a viewing angle limiting film or louver. The first LED bar 713 emits unpolarized light toward the second side. On the other hand, the second LED bar 723 emits unpolarized light toward the first side.

[0159] The first polarization adjuster 715 is affixed to the second side surface, i.e., the light output surface, of the first LED bar 713. The first polarization adjuster 715 converts the unpolarized light output from the first LED bar 713 into circularly polarized light in one direction, i.e., circularly polarized light in the L direction in this case. The second polarization adjuster 725 is affixed to the first side surface, i.e., the light output surface, of the second LED bar 723. The second polarization adjuster 725 converts the unpolarized light output from the second LED bar 723 into circularly polarized light in one direction, i.e., circularly polarized light in the L direction in this case. For example, the first polarization adjuster 715 and the second polarization adjuster 725 are each composed of an absorbing polarization filter or the like.

[0160] The stacked structure of the first LED bar 713 and the first polarization adjuster 715 is arranged with the light emission surface of the first LED bar 713 facing the second side. The stacked structure of the second LED bar 723 and the second polarization adjuster 725 is arranged with the light emission surface of the second LED bar 723 facing the first side.

[0161] The motor 736 is attached to a first side of the first LED bar 713 and a first side of the second LED bar 723. The motor 736 is capable of rotating the first laminated structure at high speed around an axis passing through the center of the first laminated structure of the first LED bar 713 and the first polarization adjuster 715. The motor 736 is also capable of rotating the second laminated structure at high speed around an axis passing through the second laminated structure of the second LED bar 723 and the second polarization adjuster 725. For example, the motor 736 is a stepping motor or the like.

[0162] (Operation) In operation of the aerial image display device 700, the display / retroreflection unit 310 rotates at high speed a laminated structure of retroreflector 311, LED bar 313, and polarization adjuster 315 to produce a semi-transparent image that serves as the basis for the first aerial image AI1 on the second side and a semi-transparent retroreflective surface on the first side. The display unit 710 also rotates at high speed a first laminated structure of first LED bar 713 and first polarization adjuster 715 to produce a semi-transparent image that serves as the basis for the second aerial image AI2 on the second side. The display unit 710 also rotates at high speed a second laminated structure of second LED bar 723 and second polarization adjuster 725 to produce a third semi-transparent image on the first side.

[0163] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0164] A portion of the unpolarized light emitted from the LED bars 313 of the display / retroreflection unit 310 passes through the polarization adjustment unit 315 and becomes circularly polarized light in the L direction. The light then passes through the transmissive area of ​​the display unit 710 and enters the reflective unit 320. The L direction circularly polarized light that entered the reflective unit 320 is reflected by the reflective unit 320 and becomes circularly polarized light in the R direction. A portion of the R direction circularly polarized light reflected by the reflective unit 320 passes through the transmissive area of ​​the display unit 710, then passes through the transmissive area of ​​the display / retroreflection unit 310, and enters the reflective / transmissive unit 140.

[0165] The R-direction circularly polarized light that enters reflective-transmissive unit 140 is reflected by reflective-transmissive unit 140 and enters display / retroreflective unit 310. A portion of the R-direction circularly polarized light that enters display / retroreflective unit 310 is retroreflected by the retroreflective surface of display / retroreflective unit 310, becomes L-direction circularly polarized light, transmits through reflective-transmissive unit 140, and forms a first aerial image AI on a first side of reflective-transmissive unit 140.

[0166] A portion of the unpolarized light emitted from the first LED bar 713 of the display unit 710 passes through the first polarization adjustment unit 715, becomes circularly polarized light in the L direction, and enters the reflecting unit 320. The L direction circularly polarized light that entered the reflecting unit 320 is reflected by the reflecting unit 320 and becomes circularly polarized light in the R direction. A portion of the R direction circularly polarized light reflected by the reflecting unit 320 passes through the transmissive area of ​​the display unit 710, then passes through the transmissive area of ​​the display / retroreflecting unit 310, and enters the reflective / transmissive unit 140.

[0167] The R-direction circularly polarized light that enters reflective-transmissive unit 140 is reflected by reflective-transmissive unit 140 and enters display / retroreflective unit 310. A portion of the R-direction circularly polarized light that enters display / retroreflective unit 310 is retroreflected by the retroreflective surface of display / retroreflective unit 310, becomes L-direction circularly polarized light, and transmits through reflective-transmissive unit 140 to form a second aerial image AI2 on the first side of reflective-transmissive unit 140.

[0168] A portion of the unpolarized light emitted from the second LED bar 723 of the display unit 710 passes through the second polarization adjuster 725, becomes circularly polarized light in the L direction, passes through the transmissive area of ​​the display / retroreflector 310, transmits through the reflective-transmissive unit 140, and is emitted to the first side of the reflective-transmissive unit 140. This emitted light is not retroreflected by the display / retroreflector 310, and therefore does not contribute to the formation of an aerial image.

[0169] A viewer of the aerial image display device 700 views the aerial image display device 700 from a first side of the first aerial image AI1 and the second aerial image AI2. At this time, the viewer can see the first aerial image AI1 and the second aerial image AI2. The reflective / transmissive unit 140 and the display / retroreflective unit 310 are semi-transparent and transmit a portion of the circularly polarized light in the L direction from the display unit 710. Therefore, the viewer can see a third semi-transparent image created by the display unit 710 in addition to the first aerial image AI1 and the second aerial image AI2.

[0170] (Effects) The aerial image display device 700 according to this embodiment can be significantly smaller in size in the depth direction than aerial image display devices using conventional methods, similar to the aerial image display device 100 according to the first embodiment. In addition, the aerial image display device 700 according to this embodiment can show the viewer a third semi-transparent image created by the display unit 710, in addition to the first aerial image AI1 and the second aerial image AI2.

[0171] Eighth Embodiment (Configuration) Next, the configuration of an aerial image display device 800 according to the eighth embodiment will be described with reference to Fig. 17. Fig. 17 is a diagram showing the configuration of the aerial image display device 800 according to the eighth embodiment. Fig. 17 is a side view corresponding to Fig. 13. In Fig. 17, components with the same reference numerals as those shown in Fig. 13 are similar components, and detailed description thereof will be omitted. The following description will focus on the differences. In other words, parts not mentioned in the following description are the same as those in the fifth embodiment.

[0172] The aerial image display device 800 according to the eighth embodiment has a display and retroreflection unit 810, a reflection / transmission unit 140, and a drive unit 10.

[0173] The aerial image display device 800 according to the eighth embodiment can be said to have a configuration in which the display / retroreflection section 510 of the aerial image display device 100 according to the fifth embodiment is replaced with a display / retroreflection section 810 .

[0174] The display / retroreflection unit 810 and the reflective / transmissive unit 140 are arranged parallel to each other and substantially perpendicular to the optical axis of the aerial image display device 100. The display / retroreflection unit 810 is arranged on the second side of the reflective / transmissive unit 140. The reflective / transmissive unit 140 is arranged on the first side of the display / retroreflection unit 810.

[0175] The display / retroreflector 810 creates a semi-transparent retroreflecting surface on a first side. In addition, the display / retroreflector 810 creates a first semi-transparent image on the first side, which is the basis of the aerial image AI. The display / retroreflector 810 also creates a second semi-transparent image on the first side.

[0176] The display / retroreflection unit 810 can be said to have a configuration in which the function of producing a second semi-transparent image is added to the function of the display / retroreflection unit 510 of the fifth embodiment.

[0177] An example of the configuration of the display / retroreflection unit 810 will be described with reference to Fig. 18. Fig. 18 is a diagram showing an example of the configuration of the display / retroreflection unit 810, and is a front view of the display / retroreflection unit 810 as seen from a first side, for example, the side of the reflective / transmissive unit 140.

[0178] The display / retroreflection unit 810 has a pair of first retroreflectors 811, a first LED bar 813, a first polarization adjustment unit 815, a pair of second retroreflectors 821, a second LED bar 823, a second polarization adjustment unit 825, and a motor 836.

[0179] The first retroreflective material 811 and the second retroreflective material 821 each have a linear blade shape, for example, an elongated plate shape, similar to the retroreflective material 511. The first retroreflective material 811 and the second retroreflective material 821 each have a retroreflective surface on a first side.

[0180] Similar to the LED bar 513, the first LED bar 813 and the second LED bar 823 have a linearly extending, elongated housing and a plurality of LEDs 814, 824 arranged linearly along the longitudinal axis in the center of the housing. The plurality of LEDs 814, 824 emit unpolarized light to the first side. The plurality of LEDs 814, 824 may be, for example, a group of multicolored LEDs. A mechanism for suppressing the spread of light, such as a viewing angle limiting film or louver, may be provided on the light exit surface of the LED bars 813, 823.

[0181] The first polarization adjuster 815 is attached to the light output surface of the first LED bar 813. The first polarization adjuster 815 converts the unpolarized light output from the first LED bar 813 into circularly polarized light in one direction, circularly polarized light in the R direction in this case. The second polarization adjuster 825 is attached to the light output surface of the second LED bar 823. The second polarization adjuster 825 converts the unpolarized light output from the second LED bar 823 into circularly polarized light in one direction, circularly polarized light in the L direction in this case. For example, the first polarization adjuster 815 and the second polarization adjuster 825 are composed of absorbing polarizing filters or the like.

[0182] A pair of first retroreflectors 811 are disposed adjacent to both sides of the first LED bar 813 and are bonded to each other. The retroreflecting surface of the first retroreflector 811 and the light-emitting surface of the first LED bar 813 face the same side. Similarly, a pair of second retroreflectors 821 are disposed adjacent to both sides of the second LED bar 823 and are bonded to each other. The retroreflecting surface of the second retroreflector 821 and the light-emitting surface of the second LED bar 823 face the same side.

[0183] The stacked structure of the first LED bar 813 and the first polarization adjuster 815 and the stacked structure of the second LED bar 823 and the second polarization adjuster 825 are fixed to overlap each other so as to intersect, for example, orthogonally cross each other. For example, the stacked structure of the second LED bar 823 and the second polarization adjuster 825 is fixed to a first side of the stacked structure of the first LED bar 813 and the first polarization adjuster 815.

[0184] The motor 836 is attached to the second side of the first retroreflector 811 and the first LED bar 813, i.e., the side opposite the retroreflecting surface and the light emitting surface. The motor 836 is capable of rotating the first laminated structure and the second laminated structure at high speed around an axis passing through the center of the first laminated structure of the first LED bar 813 and the first polarization adjuster 815 and the center of the second laminated structure of the second LED bar 823 and the second polarization adjuster 825. For example, the motor 836 is a stepping motor or the like.

[0185] In the display / retroreflection unit 810, the number of rotations of the motor 836, the position detection of each LED 814, 824, and the on / off of each LED 814, 824 are controlled by the drive unit 10. As a result, the display / retroreflection unit 810 creates, on the first side, a semi-transparent retroreflection surface, and a first semi-transparent image and a second semi-transparent image that are the basis of the aerial image AI.

[0186] (Operation) In operation of the aerial image display device 800, the display / retroreflection unit 810 has the first retroreflector 811 and second retroreflector 821 rotating at high speed to create a semi-transparent retroreflecting surface on the first side, the first LED bar 813 and first polarization adjustment unit 815 rotating at high speed to create a first semi-transparent image on the first side that is the basis of the aerial image AI, and the second LED bar 823 and second polarization adjustment unit 825 rotating at high speed to create a second semi-transparent image on the first side.

[0187] The change in the type of polarization caused by each optical element, the relationship between the type of polarization and the reflection and transmission at each optical element, etc. have already been described in the first embodiment, and will be briefly described below.

[0188] A portion of the unpolarized light emitted from first LED bar 813 passes through first polarization adjuster 815, becoming circularly polarized light in the R direction, and enters reflective-transmissive unit 140. The R-direction circularly polarized light that entered reflective-transmissive unit 140 is reflected by reflective-transmissive unit 140 and enters display / retroreflective unit 810. A portion of the R-direction circularly polarized light that entered display / retroreflective unit 810 is retroreflected by the retroreflective surface created by display / retroreflective unit 810, becoming circularly polarized light in the L direction, which passes through reflective-transmissive unit 140 and forms an aerial image AI on the first side of reflective-transmissive unit 140.

[0189] A portion of the unpolarized light emitted from the second LED bar 823 passes through the second polarization adjuster 825, becomes circularly polarized light in the L direction, transmits through the reflective-transmissive unit 140, and is emitted to the first side of the reflective-transmissive unit 140. This emitted light is not retroreflected by the display / retroreflective unit 810, and therefore does not contribute to the formation of an aerial image.

[0190] A viewer of the aerial image display device 800 views the aerial image display device 800 from the first side of the aerial image AI. At this time, the viewer can see the aerial image AI1. The reflective / transmissive unit 140 is semi-transparent and transmits a portion of the circularly polarized light in the L direction from the display / retroreflector 810. Therefore, the viewer can see not only the aerial image AI but also a second semi-transparent image created by the display / retroreflector 810.

[0191] (Effects) In the aerial image display device 800 according to this embodiment, the display / retroreflection unit 810 and the reflective / transmissive unit 140 are arranged in parallel, and therefore, similar to the aerial image display device 100 according to the first embodiment, it can be significantly smaller in size in the depth direction than aerial image display devices using conventional methods. Furthermore, since the only optical elements that the aerial image display device 800 has are the display / retroreflection unit 810 and the reflective / transmissive unit 140, the aerial image display device 800 can be configured to be extremely small in size in the depth direction. In addition, the aerial image display device 800 according to this embodiment can show the viewer a second semi-transparent image created by the display / retroreflection unit 810 in addition to the aerial image AI.

[0192] (Hardware Configuration) Next, a representative hardware configuration of the driver 10 of the aerial image display device 100 according to the first embodiment will be described. Here, an example will be described in which the driver 10 is configured as a computer. For example, the driver 10 may be configured as a personal computer, a server computer, or the like.

[0193] 19 is a block diagram showing an example of the hardware configuration of the driving unit 10 according to the embodiment. The driving unit 10 is configured by, for example, a computer. The driving unit 10 has a control device 20, a display device 40, and an input device 50.

[0194] The control device 20 controls the entire drive unit 10. The control device 20 includes a processor 21, a read only memory (ROM) 22, a random access memory (RAM) 23, and an auxiliary storage device 24.

[0195] The processor 21, ROM 22, RAM 23, auxiliary storage device 24, display device 40, and input device 50 are electrically connected to one another via a bus 30, and can transmit and receive data.

[0196] The processor 21 is configured by a general-purpose hardware processor including, for example, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit), etc. The processor 21 executes programs deployed in the RAM 23 to perform various functions of the drive unit 10.

[0197] The ROM 22 is a non-volatile memory that constitutes part of the main storage device. The ROM 22 non-temporarily stores a startup program required to start up the drive unit 10. The processor 21 loads the startup program in the ROM 22 into the RAM 23 and executes it to start up the drive unit 10. The ROM 22 is, for example, configured as an EPROM (Erasable Programmable Read Only Memory), and can store various startup settings in addition to the startup program.

[0198] The RAM 23 is a volatile memory that constitutes part of the main storage device. The RAM 23 temporarily stores programs required for processing by the processor 21 and data required for executing the programs. In other words, the RAM 23 functions as a work area for the processor 21.

[0199] The auxiliary storage device 24 is configured with non-volatile memory such as a hard disk drive (HDD) or a solid state drive (SSD). The auxiliary storage device 24 can non-temporarily store various programs executed by the processor 21 and data required for executing the programs. The processor 21 executes various functions of the drive unit 10 by loading the programs in the auxiliary storage device 24 into the RAM 23 and executing them.

[0200] The display device 40 is a device that visually outputs information and displays characters, images, etc. on a screen to provide information to a user. For example, the display device 40 is a liquid crystal display, an organic EL display, a plasma display, etc.

[0201] The input device 50 is a device for a user to input information and instructions, and accepts input of information and instructions. The input device 50 includes a keyboard, a pointing device, etc. The pointing device includes a mouse, a trackpad, a touch screen, etc.

[0202] The display device 40 and the input device 50 may be configured as a device having the functions of both. Such a device may be configured as, for example, a touch panel.

[0203] The input device 50 may also include a device that reads data from a computer-readable recording medium 60 that non-temporarily records data such as a program. For example, the recording medium 60 includes disks such as flexible disks, optical disks (CD-ROM, CD-R, DVD-ROM, DVD-R, etc.), magneto-optical disks (MO, etc.), and semiconductor memories. The input device 50 includes drives and readers for these.

[0204] The program stored in the auxiliary storage device 24 is provided to the drive unit 10, for example, via the recording medium 60. Alternatively, the program may be stored on a server on a network and provided to the drive unit 10 by downloading it.

[0205] For example, when the drive unit 10 is started, the processor 21 executes a startup program in the ROM 22 to start up the operating system (OS). Under the control of the OS, the processor 21 monitors input instructions, connections to external devices, etc. Also, under the control of the OS, the processor 21 sets up a program area and a data area in the RAM 23.

[0206] In response to an instruction to start a program, the processor 21 reads the program from the auxiliary storage device 24 into the program area of ​​the RAM 23, and also reads data necessary for executing the program from the auxiliary storage device 24 into the data area of ​​the RAM 23. The processor 21 calculates the data in the data area in accordance with the program and writes the calculation results into the data area.

[0207] Through these operations, the processor 21, RAM 23, and auxiliary storage device 24 work together to execute at least some of the functions of the control device 20. Furthermore, the control device 20, display device 40, and input device 50 work together to execute at least some of the functions of the drive unit 10.

[0208] The programs non-temporarily stored in the auxiliary storage device 24 include an aerial image display program that causes the processor 21 to execute at least part of the functions of the control device 20. In other words, the processor 21 executes this aerial image display program to execute at least part of the functions of the drive unit 10 of the aerial image display device 100.

[0209] The embodiments of the present invention have been described above with reference to the drawings. However, the above embodiment is merely an example of a configuration that embodies the present invention. That is, it is clear that the present invention is not limited to the above embodiment. Therefore, addition, omission, substitution, and other modifications of components may be made within the scope of the technical concept of the present invention.

[0210] For example, as an example of the configuration of the retroreflective unit 130, a configuration in which a semi-transparent retroreflective surface is created by high-speed rotation of the retroreflective material 13 has been shown. However, the retroreflective unit 130 may be configured to create a semi-transparent retroreflective surface by high-speed movement of the retroreflective material 13. In other words, the movement of the retroreflective material 13 to create the semi-transparent retroreflective surface is not limited to rotation, and may be other movement such as reciprocating movement, vibration, or swinging.

[0211] In short, the present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0212] DESCRIPTION OF SYMBOLS 10...Drive unit 20...Control device 21...Processor 22...ROM 23...RAM 24...Auxiliary storage device 30...Bus 40...Display device 50...Input device 60...Recording medium 100...Aerial image display device 110...Display unit 120...Polarization adjustment unit 130...Retroreflection unit 131...Retroreflection material 132...Shaft 136...Motor 140...Reflection-transmission unit 141...Transparent plate 142...Retardation film 143...Reflective polarization film 150...Retroreflection unit 151...Retroreflection material 152...Shaft 156...Motor 160...Retroreflection unit 161...Retroreflection material 162...Shaft 166...Motor 200...Aerial image display device 210...First display unit 220...Second display unit 223...LED bar 224...LED 226...Motor 230...Polarization adjustment unit 300...Aerial image display device 310...Display / retroreflecting unit 311...Retroreflecting material 313...LED bar 314...LED 315...Polarization adjustment unit 316...Motor 320...Reflecting unit 330...Retroreflecting unit 340...Display unit 400...Aerial image display device 410...Display unit 413...LED bar 415...Polarization adjustment unit 416...Motor 500...Aerial image display device 510...Display / retroreflecting unit 511...Retroreflecting material 513...LED bar 515...Polarization adjustment unit 516...Motor 600...Aerial image display device 610...Polarization adjustment unit 700...Aerial image display device 710...Display unit 713...First LED bar 715...First polarization adjustment unit 723...Second LED bar 725... Second polarization adjustment section 736... Motor 800... Aerial image display device 810... Display / retroreflection section 811... First retroreflector 813... First LED bar 814... LED 815... First polarization adjustment section 821... Second retroreflector 823... Second LED bar 824... LED 825... Second polarization adjustment section 836... Motor AI... Aerial image AI1... First aerial image AI2... Second aerial image

Claims

1. An aerial image display device comprising: a display unit that displays an image on a first side; a retroreflective unit that is arranged on the first side of the display unit and creates a semi-transparent retroreflective surface by high-speed movement of retroreflective material; and a reflective-transmissive unit that is arranged on the first side of the retroreflective unit and reflects part of incident light and transmits part of it.

2. The aerial image display device according to claim 1, wherein the display unit emits circularly polarized light in one direction.

3. The aerial image display device according to claim 1, further comprising a polarization adjustment unit that converts the light emitted from the display unit from circularly polarized light in one direction.

4. An aerial image display device as described in claim 1, wherein the display unit has a first display unit that displays an image, and a second display unit that produces a semi-transparent image and is arranged on the first side of the first display unit.

5. An aerial image display device comprising: a reflecting section that reflects incident light from a first side; a display / retroreflective section that is disposed on the first side of the reflecting section and creates a semi-transparent image on a second side opposite the first side, creating a semi-transparent retroreflective surface on the first side; and a reflective / transmissive section that is disposed on the first side of the display / retroreflective section and reflects part of the incident light and transmits part of it.

6. An aerial image display device comprising: a display / retroreflection unit that produces a semi-transparent image and a semi-transparent retroreflection surface on a first side; and a reflection / transmission unit that reflects part of incident light and transmits part of it, located on the first side of the display / retroreflection unit.

7. A method for displaying an aerial image, comprising: displaying an image on a first side; creating a semi-transparent retroreflective surface on the first side of the image by moving a retroreflective material at high speed; and reflecting part of incident light and transmitting part of the light on the first side of the retroreflective surface.

8. An aerial image display program that causes a computer to execute the driving of the display unit and the retroreflecting unit according to claim 1.

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