Aerial image display device

Abstract

An aerial image display device according to one embodiment displays an aerial image on a first reflection surface including a first direction and a second direction intersecting the first direction. The aerial image display device includes: a display having a display surface facing from one end side to the other end side in the first direction, a beam splitter, and a retroreflective material. At least a portion of the first outgoing light based on the display of the display surface reflected by the beam splitter is retroreflected by the retroreflective material, at least a portion of the retroreflected first outgoing light is transmitted through the beam splitter from the other end side to the one end side in the first direction, at least a portion of the transmitted first outgoing light is reflected by the first reflection surface, and the aerial image is formed by at least a portion of the first outgoing light reflected by the first reflection surface.

Description

Aerial image display device

[0001] The embodiment relates to an aerial image display device.

[0002] Technologies for displaying images on a display as aerial images have been researched. For example, as described in Non-Patent Document 1, AIRR (Aerial Imaging by Retro-Reflection) is known, which displays aerial images using a retroreflective material and a beam splitter. With such technologies, the device that displays the aerial image is often placed in the line of sight, which can make it difficult to blend the aerial image into the environment.

[0003] Therefore, the system described in Non-Patent Document 2 proposes a tabletop aerial image display system that is less restricted in its installation location. This system is called PortOn. In this system, the presence of the device is reduced by using surrounding reflective surfaces as part of the optical system. This makes it possible to display aerial images that blend into the environment.

[0004] Hirotsugu Yamamoto, "Aerial display using aerial imaging by retroreflection (AIRR)," Journal of the Imaging Society of Japan, Vol. 56, No. 4, pp. 341-351, 2017, doi 10.11370 / isj.56.341; Naoya Koizumi, Ayaka Sano, "Optical system to display mid-air images on a glossy plane and remove ground images," Optics Express, vol. 28, Issue 18, pp. 26750-26763, 2020, doi 10.1364 / OE.400104; Kota Murofushi, Naoki Hashimoto, "Expanding the viewing zone of 3D aerial images by combining multiple 3D displays," Journal of the Virtual Reality Society of Japan, Vol. 25, No. 4, pp. 432-438, 2020, doi 10.18974 / tvrsj.25.4_432Tomoyo Kikuchi, Yuchi Yahagi, Shogo Fukushima, Saki Sakaguchi, Takeshi Naemura, “AIR-range: Designing optical systems to present a tall mid-AIR image with continuous luminance on and above a tabletop”, ITE Trans. on MTA, vol. 11, No. 2, pp. 75-87, 2023, doi 10.3169 / mta.11.75

[0005] However, in an optical system in which the line of sight and the display surface of the display are arranged to face each other as described in Non-Patent Document 2, a problem can arise in that the transmitted light that simply passes through the retrotransmitting element without being retrotransmitted by the retrotransmitting element is observed by the user. Therefore, Non-Patent Document 2 describes a field of view control film that is arranged in the optical path to eliminate the influence of transmitted light that is directly visible from the display, as described above. In such cases, the field of view control film can cause a problem of reducing the brightness and image quality of the aerial image.

[0006] The present invention has been made in view of the above circumstances, and its object is to provide a means for preventing a decrease in brightness and image quality due to measures for eliminating the influence of transmitted light.

[0007] In one embodiment, the aerial image display device displays an aerial image on a first reflective surface that includes a first direction and a second direction intersecting the first direction, and includes: a display having a display surface facing from one end side to the other end side in the first direction; a beam splitter having a second reflective surface; and a retroreflective material having a third reflective surface facing from the other end side to one end side in the first direction, wherein at least a portion of a first emitted light based on the display on the display surface is reflected by the second reflective surface of the beam splitter, at least a portion of the reflected first emitted light is retroreflected by the third reflective surface of the retroreflective material, at least a portion of the retroreflected first emitted light transmits through the beam splitter from the other end side to one end side in the first direction, at least a portion of the transmitted first emitted light is reflected by the first reflective surface, and the aerial image is formed by at least a portion of the first emitted light reflected by the first reflective surface.

[0008] Another embodiment of the aerial image display device is an aerial image display device that displays an aerial image on a first reflecting surface that includes a first direction and a second direction that intersects the first direction, and includes a display having a display surface facing from one end side to the other end side in the first direction, and a retrotransmitting element, wherein at least a portion of the first emitted light based on the display on the display surface passes through the retrotransmitting element from the other end side to the one end side in the first direction, at least a portion of the transmitted first emitted light is reflected by the first reflecting surface, and the aerial image is formed by at least a portion of the first emitted light reflected by the first reflecting surface.

[0009] According to the embodiment, it is possible to provide a means for preventing a decrease in brightness and image quality due to measures for eliminating the influence of transmitted light.

[0010] FIG. 1 is a block diagram showing an example of the configuration of an aerial image display device according to the first embodiment. FIG. 2 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the first embodiment. FIG. 3 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the second embodiment. FIG. 4 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the third embodiment. FIG. 5 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the fourth embodiment. FIG. 6 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the fourth embodiment. FIG. 7 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the fourth embodiment. FIG. 8 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the fifth embodiment. FIG. 9 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the sixth embodiment. FIG. 10 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the seventh embodiment. FIG. 11 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the eighth embodiment.

[0011] Hereinafter, several embodiments will be described with reference to the drawings. In the following description, components having the same function and configuration will be assigned the same reference numerals. In the following description, two horizontal directions that intersect with each other will be referred to as the X direction and the Y direction, respectively. A direction that intersects with both the X direction and the Y direction will be referred to as the Z direction.

[0012] The aerial image display device described below is a device equipped with an optical system configured to display an image on a display as an aerial image using a reflective surface.

[0013] 1 First Embodiment A system including an aerial image display device according to a first embodiment will be described.

[0014] The system includes an aerial image display device and a reflector having a reflective surface for displaying an aerial image. The reflector may be included in the aerial image display device. The aerial image display device may be, for example, a tabletop device.

[0015] 1.1 Hardware Configuration First, the hardware configuration of the aerial image display device according to the first embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram showing an example of the configuration of the aerial image display device according to the first embodiment.

[0016] The aerial image display device 1 includes, for example, a processor 11 , a ROM (Read Only Memory) 12 , a RAM (Random Access Memory) 13 , a storage 14 , an interface 15 , and a display unit 16 .

[0017] The processor 11 is a processing circuit capable of executing various programs. The processor 11 controls the overall operation of the aerial image display device 1. The processor 11 is, for example, a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). Note that the aerial image display device 1 may include multiple processors.

[0018] The ROM 12 is a non-volatile semiconductor memory that stores programs and control data for controlling the aerial image display device 1.

[0019] The RAM 13 is a volatile semiconductor memory such as a dynamic random access memory (DRAM) or a static random access memory (SRAM). The RAM 13 is used as a working area for the processor 11.

[0020] The storage 14 is a non-volatile storage device such as a hard disk drive (HDD), a solid state drive (SSD), or a memory card. The storage 14 stores various types of information and data. The storage 14 may store video data for displaying an aerial image on the aerial image display device 1. The storage 14 may also store programs and control data.

[0021] The interface 15 is, for example, an interface circuit that can input video data for displaying an aerial image on the aerial image display device 1 .

[0022] The display unit 16 mainly constitutes an optical system for displaying an aerial image based on video data as a real image using the reflective surface of a reflective material. This optical system will be described later.

[0023] 1.2 Configuration of the Optical System The configuration of the optical system of a system including the aerial image display device 1 will be described with reference to FIG. 2. FIG. 2 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the first embodiment. FIG. 2 shows the configuration of a system including the aerial image display device 1 when viewed in the Y direction. The schematic diagram showing the configuration of a system including an aerial image display device also shows the user's line of sight LOS and the aerial image displayed by the system. In the following description, the user side of the user and the aerial image display device 1 will be referred to as one end side in the X direction. Furthermore, the aerial image display device 1 side of the user and the aerial image display device 1 will be referred to as the other end side in the X direction.

[0024] The optical system of the system including the aerial image display device 1 includes a display Dsp1, a reflector RR1, a beam splitter BS1, and a reflector RS1. The display Dsp1, the reflector RR1, and the beam splitter BS1 are included in a display unit 16 of the aerial image display device 1.

[0025] The display Dsp1 is, for example, a flat display whose image display surface is arranged on the YZ plane. The display Dsp1 is arranged so that the display surface faces from one end to the other end in the X direction. In other words, the display Dsp1 is arranged so that the user does not directly view the display surface. Note that the display Dsp1 may be arranged so that the display surface faces from one end to the other end in the X direction. Although not shown in FIG. 2 , the display Dsp1 may be arranged at an angle so that the height increases from one end to the other end in the X direction.

[0026] The reflector RR1 is a retroreflective material having a reflective surface configured to retroreflect incident light. The reflector RR1 is, for example, a prism-type retroreflective material or a bead-type retroreflective material. The reflector RR1 is disposed so that the reflective surface faces the display surface of the display Dsp1, for example, when viewed in the Y direction. The reflector RR1 is disposed so that the reflective surface faces from the other end to one end in the X direction. In the first embodiment, the reflector RR1 is disposed so that it is tilted downward from one end to the other end in the X direction, for example.

[0027] The beam splitter BS1 is, for example, a non-polarizing beam splitter. The beam splitter BS1 is, for example, disposed below the display Dsp1 and parallel to the XY plane. The length in the Z direction between the beam splitter BS1 or its extension and the lower edge of the display surface of the display Dsp1 (the length on the extension of the display surface) is length H.

[0028] The reflector RS1 is, for example, a familiar structure having a flat surface, such as a table. The reflective surface of the reflector RS1 is, for example, the top surface of a table. The reflective surface of the reflector RS1 may be, for example, a flat surface on which a half mirror or a glossy film is installed, or a flat surface on which a reflective surface is formed by applying a glossing agent. Furthermore, as described above, the reflector RS1 may be a structure included in the aerial image display device 1. In this case, the reflector RS1 is, for example, a half mirror or the like included in the aerial image display device 1.

[0029] The reflecting surface of the reflector RS1 is parallel to the XY plane. The reflecting surface is located on the upper surface of the reflector RS1. The reflector RS1 is located below the beam splitter BS1. The length in the Z direction between the reflecting surface of the reflector RS1 and the beam splitter BS1 or its extension is, for example, equal to the length H.

[0030] In the above configuration, as indicated by the solid arrows in Figure 2, at least a portion of the emitted light based on the image on display Dsp1 is specularly reflected by, for example, beam splitter BS1. At least a portion of the emitted light reflected by beam splitter BS1 is retroreflected by reflector RR1 and then transmitted through beam splitter BS1. Furthermore, at least a portion of the emitted light transmitted through beam splitter BS1 is specularly reflected by reflector RS1. Then, an aerial image I1 is formed on the reflective surface of reflector RS1 by the light reflected by reflector RS1. In this way, the aerial image display device 1 is configured to allow a user to observe the aerial image I1.

[0031] 1.3 Effects of the First Embodiment According to the first embodiment, the aerial image display device 1 includes a display Dsp1 having a display surface facing from one end to the other end in the X direction, a beam splitter BS1, and a reflector RR1. The aerial image display device 1 is configured such that at least a portion of the emitted light based on the display on the display surface of the display Dsp1 is transmitted through the beam splitter BS1 from the other end to the one end in the X direction by the beam splitter BS1 and the reflector RR1. The aerial image display device 1 is also configured such that at least a portion of the transmitted emitted light is reflected by a reflective surface of a reflector RS1 parallel to the XY plane, thereby forming an aerial image. This configuration prevents the user from directly observing the emitted light from the display surface of the display Dsp1. This prevents degradation of the image quality, such as the brightness and resolution, of the aerial image, due to measures to eliminate the influence of transmitted light.

[0032] To further clarify, for example, when a display is positioned so that the display surface and the line of sight are opposite to each other, a view control film is provided to eliminate the effect of light that simply passes through a retrotransmitting element such as an MMAP (micro mirror array plate) without retrotransmitting. However, in this case, the intensity of the transmitted light is reduced, and the light intensity of the aerial image is also reduced. This results in a problem of reduced brightness and image quality of the aerial image.

[0033] According to the first embodiment, the configuration described above means that the direction of the display surface of the display Dsp1 and the line of sight direction LOS are not opposite each other, so no view control film is required. This prevents a reduction in light intensity due to the view control film. This prevents a decrease in the brightness and image quality of the aerial image.

[0034] Furthermore, according to the first embodiment, the light reflected by the reflective surface of the reflector RS1 is observed as the aerial image I1, thereby suppressing degradation of the aerial image due to light reflected by the reflector, thereby preventing a decrease in the brightness and image quality of the aerial image.

[0035] Furthermore, the optical system of the first embodiment is configured using a reflector RR1 and a beam splitter BS1. This makes it easier to increase the size of the optical system compared to when a retrotransmissive element such as an MMAP is used. Therefore, the size of the optical system is limited, which prevents the size of the aerial image from being limited.

[0036] Furthermore, when the display Dsp1 is positioned so as to tilt upward from one end to the other end in the X direction, the high-brightness light emitted in the front direction of the display Dsp1 can be efficiently incident on the beam splitter BS1, thereby improving the brightness of the aerial image.

[0037] 2 Second Embodiment Next, a system including an aerial image display device according to a second embodiment will be described.

[0038] The second embodiment differs from the first embodiment in that the beam splitter is disposed so that the beam splitter or its extension intersects with the reflecting surface of the reflector or its extension when viewed in the Y direction. The following mainly describes the configuration that differs from the first embodiment.

[0039] The configuration of an optical system of a system including the aerial image display device 1a will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the second embodiment.

[0040] The optical system of the system including the aerial image display device 1a includes a display Dsp2, a reflector RR2, a beam splitter BS2, and a reflector RS2.

[0041] The display Dsp2 is disposed, as viewed in the Y direction, at an angle so that the height increases from one end side to the other end side in the X direction.

[0042] The beam splitter BS2 is disposed at an angle so that it becomes lower from one end to the other end in the X direction. As a result, the beam splitter BS2 is disposed so that the beam splitter BS2 or an extension thereof intersects with the reflector RS2 or an extension thereof when viewed in the Y direction. The beam splitter BS2 may be disposed, for example, so that the other end of the beam splitter BS2 is in contact with the reflective surface of the reflector RS1.

[0043] In the second embodiment, the reflecting surface of the reflector RR2 may be configured to be perpendicular to the line of sight direction LOS when viewed in the Y direction. In this case, the beam splitter BS2 may be arranged parallel to the YZ plane or tilted so that the height increases from one end to the other end in the X direction.

[0044] In the above configuration, when viewed in the Y direction, the length on the extension line of the display Dsp2 between the lower end of the display Dsp2 and the beam splitter BS2 or its extension line is, for example, length H. Furthermore, at the position in the X direction where the aerial image I2 is formed, the length in the Z direction between the reflective surface of the reflector RS2 and the beam splitter BS2 or its extension line is, for example, equal to length H. This length corresponds to the length between the beam splitter or its extension line and the reflective surface of the reflector in the first embodiment.

[0045] The second embodiment also provides the same effects as the first embodiment.

[0046] Furthermore, according to the second embodiment, the beam splitter BS2 is disposed such that, when viewed in the Y direction, the beam splitter BS2 or its extension intersects with the reflector RS2 or its extension. Furthermore, the display Dsp2 is disposed, when viewed in the Y direction, at an angle that increases in height from one end to the other end in the X direction. With the above-described configuration, the aerial image display device 1a is configured so that high-brightness light emitted in the front direction of the display Dsp2 is efficiently incident on the beam splitter BS2. This configuration can suppress a decrease in brightness of the aerial image.

[0047] Furthermore, as described above, the beam splitter BS2 is configured to be inclined relative to the reflector RS2, thereby making it possible to prevent the height of the aerial image display device 1 from increasing in the Z direction.

[0048] Furthermore, as described above, when the reflector RR2 is disposed so as to be perpendicular to the line of sight LOS when viewed in the Y direction, if the reflector RR2 is a prism-type retroreflective material, it is possible to suppress a decrease in brightness of the aerial image. That is, by setting the angle of incidence on the prism-type retroreflective material to approximately 0 degrees and improving the reflectance of the reflector RR2, a decrease in brightness can be suppressed. Furthermore, even if the reflector RR2 is a bead-type retroreflective material, the light reflected by the reflector RR2 and the line of sight LOS become nearly parallel to each other, thereby suppressing a decrease in brightness and a change in brightness when, for example, the line of sight LOS is moved up or down.

[0049] 3 Third Embodiment Next, a system including an aerial image display device according to a third embodiment will be described.

[0050] The third embodiment differs from the first embodiment in that a system including the aerial image display device is configured to display an image straddling the reflective surface of a reflector. The following mainly describes the configuration that differs from the first embodiment.

[0051] The configuration of an optical system of a system including the aerial image display device 1b will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the third embodiment.

[0052] The optical system of the system including the aerial image display device 1b includes a display Dsp3, a reflector RR3, a beam splitter BS3, and a reflector RS3.

[0053] The display Dsp3 is positioned so that, when viewed in the Y direction, the length in the Z direction (the length on the extension of the display surface) between the bottom end of the display Dsp3 and the beam splitter BS3 or its extension is shorter than the length H between the beam splitter BS3 or its extension and the reflective surface of the reflector RS3.

[0054] With the above configuration, an aerial image I3 is formed in an area RA1 at a height equal to or higher than the reflective surface of the reflector RS3, as shown by the solid line in Fig. 4, by at least a portion of the light emitted from a portion of the display Dsp3 included in an area RD1 whose length in the Z direction from the beam splitter BS3 is equal to or greater than the length H. Furthermore, a virtual image I' is observed in an area RA2 below the reflective surface of the reflector RS3, as shown by the dashed-dotted line in Fig. 4, by at least a portion of the light emitted from a portion of the display Dsp3 included in an area RD2 whose length in the Z direction from the beam splitter BS3 is less than the length H.

[0055] The third embodiment also provides the same effects as the first embodiment.

[0056] Furthermore, according to the third embodiment, the aerial image I3 is configured to display an image that straddles the reflective surface of the reflector RS3, thereby enabling the image representation to be expanded. Furthermore, the system for realizing such an image representation can be completed on a tabletop.

[0057] 4 Fourth Embodiment Next, a system including an aerial image display device according to a fourth embodiment will be described.

[0058] The fourth embodiment differs from the first embodiment in that the aerial image display device has a mirror for utilizing light emitted laterally from the display to form an aerial image. The following mainly describes the configuration that differs from the first embodiment.

[0059] The configuration of the optical system of a system including the aerial image display device 1c will be described with reference to Fig. 5. Fig. 5 is a schematic diagram showing an example of the configuration of a system including an aerial image display device according to a fourth embodiment. Fig. 5 is a schematic diagram showing the aerial image display device as viewed from the X direction.

[0060] The optical system of the system including the aerial image display device 1c includes a display Dsp4, a reflector RR4, a beam splitter BS4, a reflector RS4, and mirrors M1 and M2. The display Dsp4, the reflector RR4, the beam splitter BS4, and the mirrors M1 and M2 are included in a display unit 16.

[0061] In the following description, the area above the beam splitter BS4 and the area below the beam splitter BS4 are referred to as areas UP and LP, respectively.

[0062] The mirrors M1 and M2 are, for example, mirrors or beam splitters. If the mirrors M1 and M2 are beam splitters, the beam splitters may be given reflective polarization properties to suppress brightness reduction. In this case, the direction of the reflection axis of the beam splitter needs to be aligned with the reflection axis of the beam splitter BS4 in the portion included in the region UP and with the transmission axis in the portion included in the region LP. The mirrors M1 and M2 are arranged so that the reflection surfaces of the mirrors M1 and M2 intersect with the reflection surface of the reflector RS4. The mirrors M1 and M2 are arranged, for example, so that the reflection surfaces of the mirrors M1 and M2 are parallel to the XZ plane. The mirrors M1 and M2 are also arranged so that the reflection surfaces of the mirrors M1 and M2 face each other. The mirrors M1 and M2 are arranged so that the reflection surfaces of the display Dsp4, reflector RR4, beam splitter BS4, and reflector RS4 are sandwiched between them. The mirrors M1 and M2 are provided, for example, from a height below the reflecting surface of the reflector RS4 to a height above the top end of the reflector RR4.

[0063] The optical path in the above configuration will be described using Fig. 6 and Fig. 7 in addition to Fig. 5 . Fig. 6 and Fig. 7 are schematic diagrams showing an example of the configuration of a system including an aerial image display device according to a fourth embodiment. Fig. 6 shows an example of a system including an aerial image display device in an area UP when viewed from the Z direction. Fig. 7 shows an example of a system including an aerial image display device in an area LP when viewed from the Z direction. Note that in Fig. 6 and Fig. 7 , the reflector RR4 and the reflector RS4 are omitted from illustration in order to make the drawings easier to understand.

[0064] The following description will be given taking as an example the light emitted from the display Dsp4 toward the mirror M1. The same applies to the light emitted from the display Dsp4 toward the mirror M2, except that the light path is symmetrical in the Y direction.

[0065] At least a portion of the outgoing light emitted from point Pd in ​​display Dsp4 toward mirror M1 is specularly reflected by mirror M1, for example. At least a portion of the outgoing light reflected by mirror M1 is specularly reflected at point Pbs of beam splitter BS4. At least a portion of the outgoing light reflected at point Pbs is retroreflected at point Pr of reflector RR4. At least a portion of the outgoing light reflected at point Pr is transmitted through beam splitter BS4 at point Pbs. At least a portion of the outgoing light transmitted at point Pbs is specularly reflected again by mirror M1 in region LP. At least a portion of the outgoing light reflected by mirror M1 is specularly reflected by point Prs on the reflective surface of reflector RS4. The light reflected in this manner contributes to the formation of an aerial image I4 at image point Pi.

[0066] With this configuration, the same effects as in the first embodiment can be achieved.

[0067] Furthermore, according to the fourth embodiment, by providing mirrors M1 and M2, it is possible to suppress a reduction in the viewing zone in which the aerial image I4 can be observed without any loss. Additionally, if there is no mirror that reflects the light emitted laterally from the display, the viewing zone of the aerial image depends on the Y-direction width of the reflector, beam splitter, and reflective surface of the reflector. In the fourth embodiment, mirrors M1 and M2 reflect the light emitted laterally from the display and make it available for imaging, thereby suppressing loss of the aerial image. Therefore, it is possible to suppress a reduction in the viewing zone.

[0068] Furthermore, by arranging the mirrors M1 and M2 so that they are perpendicular to the reflecting surface of the reflector RS4, it is possible to effectively prevent the viewing zone from being reduced.

[0069] 5. Fifth Embodiment Next, a system including an aerial image display device according to a fifth embodiment will be described.

[0070] The fifth embodiment differs from the first embodiment in that a system including the aerial image display device is configured to utilize the polarization characteristics of light. The following mainly describes the configuration that differs from the first embodiment.

[0071] The configuration of an optical system of a system including an aerial image display device 1d will be described with reference to Fig. 8. Fig. 8 is a schematic diagram showing an example of the configuration of a system including an aerial image display device according to a fifth embodiment.

[0072] The optical system of the system including the aerial image display device 1d includes a display Dsp5, a reflector RR5, a beam splitter BS5, a reflector RS5, a wave plate Wp, and a polarizing film PR. The display Dsp5, the reflector RR5, the beam splitter BS5, the wave plate Wp, and the polarizing film PR are included in a display unit 16.

[0073] The display Dsp5 is, for example, a polarized display that uses P-polarized light or S-polarized light. Fig. 8 illustrates a case where the display Dsp5 is a polarized display that uses P-polarized light.

[0074] The wave plate Wp is a λ / 4 wave plate and covers the reflecting surface of the reflector RR5.

[0075] The polarizing film PR is, for example, a reflective polarizing film that reflects P-polarized light and transmits S-polarized light when the display Dsp5 is a P-polarized polarized display. Furthermore, the polarizing film PR is, for example, a reflective polarizing film that reflects S-polarized light and transmits P-polarized light when the display Dsp5 is an S-polarized polarized display. The polarizing film PR covers the upper surface of the beam splitter BS5. In other words, the polarizing film PR covers the surface of the beam splitter BS5 that faces the display Dsp5 and reflector RR5 among the display Dsp5, reflector RR5, and reflector RS5.

[0076] The optical path in the optical system of a system including an aerial image display device 1d according to the fifth embodiment will be described using an example in which the display Dsp5 is a P-polarized polarized display. At least a portion of the P-polarized light based on the image on the display Dsp5 is specularly reflected by the beam splitter BS5. At least a portion of the P-polarized light reflected by the polarizing film PR is retroreflected by the reflector RR5 covered by the wave plate Wp, thereby rotating the polarization direction and becoming S-polarized light. At least a portion of the S-polarized light is transmitted through the polarizing film PR and the beam splitter BS5. At least a portion of the S-polarized light transmitted through the beam splitter BS5 is specularly reflected by the reflector RS5. An aerial image I5 is then formed by the light reflected by the reflector RS5.

[0077] The fifth embodiment also provides the same effects as the first embodiment.

[0078] Furthermore, according to the fifth embodiment, by using a polarized display as the display Dsp5 and providing a polarizing film PR on the reflective surface of the beam splitter BS5, it is possible to improve the reflectance of the light from the display Dsp5 and the transmittance of the light from the reflector RR5 at the beam splitter BS5. This configuration also makes it possible to suppress a decrease in the brightness of the aerial image.

[0079] Although not shown, the aerial image display device 1d may further include a polarizing film that covers the reflective surface of the reflector RS5. The polarizing film is a reflective polarizing film that reflects S-polarized light and transmits P-polarized light. If the aerial image display device 1d includes the reflective polarizing film, the reflectance of the reflective surface of the reflector RS5 can also be improved. This configuration also helps prevent a decrease in the brightness of the aerial image.

[0080] 6 Sixth Embodiment Next, a system including an aerial image display device according to a sixth embodiment will be described.

[0081] The sixth embodiment differs from the first embodiment in that the display of a tablet terminal is used as the reflector. The following mainly describes the configuration that differs from the first embodiment.

[0082] A system including an aerial image display device 1e according to the sixth embodiment includes a tablet terminal TAB. The aerial image display device 1e may be configured to be able to communicate with the tablet terminal TAB. This allows, for example, the system to be configured to be able to transfer information and data between the aerial image display device 1e and the tablet terminal TAB.

[0083] The configuration of an optical system of a system including an aerial image display device 1e will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing an example of the configuration of a system including an aerial image display device according to a sixth embodiment.

[0084] The optical system of the system including the aerial image display device 1e includes a display Dsp6, a reflector RR6, a beam splitter BS6, and a tablet terminal TAB.

[0085] The optical system of the system including the aerial image display device 1e uses the display of the tablet terminal TAB instead of the reflective material of the optical system in the first embodiment. A glossy film may be provided on the display of the tablet terminal TAB. This improves the glossiness of the display of the tablet terminal TAB and reduces roughness, thereby improving the reflectivity. This prevents a decrease in the brightness and image quality of the aerial image.

[0086] In the above configuration, a system including the aerial image display device 1e can display, for example, an aerial image based on an image on the display Dsp6 in combination with an image on the display of the tablet terminal TAB.

[0087] The sixth embodiment also provides the same effects as the first embodiment.

[0088] Furthermore, according to the sixth embodiment, an aerial image based on the image on the display Dsp6 is combined with the image on the display of the tablet terminal TAB. This allows an image parallel to the reflective surface of the reflector RS6 to be added to the aerial image I6 perpendicular to the reflective surface of the reflector RS6. This allows for an expansion of the image representation.

[0089] 7 Seventh Embodiment Next, a system including an aerial image display device according to a seventh embodiment will be described.

[0090] The seventh embodiment differs from the first embodiment in that a retrotransmitting optical element is used. The following mainly describes the configuration that differs from the first embodiment.

[0091] The configuration of an optical system of a system including an aerial image display device if according to the seventh embodiment will be described with reference to Fig. 10. Fig. 10 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the seventh embodiment.

[0092] The optical system of the system including the aerial image display device 1f includes a display Dsp7, an element P, and a reflector RS6. The display Dsp7 and the element P are included in a display unit 16.

[0093] The element P is a retrotransmissive element such as an MMAP. The element P is provided between the display Dsp7 and the reflector RS6 in the Z direction. The element P is provided, for example, parallel to the XY plane, similar to the reflector RS6.

[0094] The element P is provided to correspond to the beam splitter in the first embodiment. As a result, the length in the Z direction between the element P or its extension and the lower end of the display surface of the display Dsp7 (the length on the extension of the display surface) is length H. Furthermore, the length in the Z direction between the reflective surface of the reflector RS7 and the element P or its extension is, for example, equal to length H.

[0095] 10 , the element P transmits at least a portion of the emitted light based on the image on the display Dsp7 symmetrically in the X direction from the other end toward the one end of the element P. As in the first embodiment, an aerial image I7 is formed on the reflective surface of the reflector RS6 by at least a portion of the emitted light transmitted in this manner.

[0096] In the seventh embodiment, the element P may be disposed at an angle so as to become lower from one end to the other end in the X direction, similar to the beam splitter BS2 in the second embodiment.

[0097] Even when a retrotransmitting element such as an MMAP is used as in the seventh embodiment, the same effects as those of the first embodiment are achieved.

[0098] Furthermore, for example, in the case of an AIRR such as that described in Non-Patent Document 4, the size of the device is large and it may be difficult to complete the system on a table, but according to the configuration of the seventh embodiment, even when a retrotransmissive element such as an MMAP is used, the increase in size of the device can be suppressed and the system can be completed on a table. Furthermore, according to the seventh embodiment, the structure can be made simpler than that of an AIRR such as that described in Non-Patent Document 4.

[0099] Furthermore, according to the seventh embodiment, even when a retrotransmitting element such as an MMAP is used, an increase in the number of reflections can be suppressed. For example, in the configuration described in Non-Patent Document 4, a minimum of four reflections are required, including reflection on the mirror, two reflections inside the MMAP, and reflection on the reflective surface. In other words, when a retrotransmitting element such as an MMAP is used, the number of reflections may be increased. According to the seventh embodiment, with the above-described configuration, an aerial image is formed through a minimum of three reflections, including two reflections within the element P and reflection on the reflector RS6. This also suppresses, for example, a decrease in the brightness and image quality of the aerial image.

[0100] 8 Eighth Embodiment Next, a system including an aerial image display device according to an eighth embodiment will be described.

[0101] The eighth embodiment differs from the first embodiment in that the reflector is arranged so as to be substantially parallel to the beam splitter and the reflecting material. The following mainly describes the configuration that differs from the first embodiment.

[0102] The configuration of an optical system of a system including an aerial image display device 1g according to the eighth embodiment will be described with reference to Fig. 11. Fig. 11 is a schematic diagram showing an example of the configuration of a system including the aerial image display device according to the eighth embodiment.

[0103] The optical system of the system including the aerial image display device 1g includes a display Dsp8, a reflector RR7, a beam splitter BS7, and a reflector RS7.

[0104] The reflector RR7 is disposed so as to be substantially parallel to the XY plane. The reflector RR7 is configured so that the reflective surface of the reflector RR7 faces downward. The reflector RR7 is disposed, for example, above the display Dsp8.

[0105] The eighth embodiment also provides the same effects as the first embodiment.

[0106] Furthermore, according to the eighth embodiment, it is possible to prevent the observation of stray light caused by specular reflection rather than retroreflection at the reflector RR7. To further explain, for example, a portion of the light emitted from the display may be specularly reflected by the reflector. Such specularly reflected light from the reflector becomes stray light that does not contribute to the formation of an aerial image. According to the eighth embodiment, the optical system of the system including the aerial image display device 1g is configured, as shown in FIG. 11 , so that stray light caused by specular reflection from the reflector is directed toward the other end in the X direction. This prevents the user from accidentally observing stray light caused by the reflector.

[0107] 9. Modifications, etc. Various modifications can be applied to the above-described first, second, third, fourth, fifth, sixth, seventh, and eighth embodiments.

[0108] For example, the first, second, or eighth embodiment may be combined with at least one of the arrangement of the display in the third embodiment, the provision of a mirror in the fourth embodiment, the provision of a wave plate and a polarizing film in the fifth embodiment, and the use of a tablet as in the sixth embodiment. Also, for example, the seventh embodiment may be combined with at least one of the arrangement of the display in the third embodiment, the provision of a mirror in the fourth embodiment, the provision of a wave plate and a polarizing film in the fifth embodiment, and the use of a tablet as in the sixth embodiment.

[0109] Furthermore, the displays used in the first to eighth embodiments may be stereoscopic displays. In this case, a system including the aerial image display device can display a stereoscopic aerial image as an aerial image.

[0110] Furthermore, in the first to eighth embodiments described above, the configuration of the optical system of the system including the aerial image display device may be inverted in the Z direction. That is, the optical system of the system including the aerial image display device may have a configuration in which the optical system configurations of the first to eighth embodiments described above are inverted upside down. In this case, the optical system of the system including the aerial image display device may be configured, for example, so that the reflector is located above the display. Furthermore, the reflective surface of the reflector may be, for example, the ceiling surface instead of the top surface of a table. Furthermore, when a reflector is configured to be included in the aerial image display device, the reflector may be, for example, a half mirror included in the aerial image display device.

[0111] Furthermore, in the first to eighth embodiments described above, the optical system of the system including the aerial image display device may be rotated 90° clockwise or counterclockwise around the Y direction as the rotation axis. In this case, the reflective surface of the reflector may be, for example, a wall surface instead of the top surface of a table. Furthermore, when the aerial image display device includes a reflective material, the reflective material may be, for example, a half mirror or the like included in the aerial image display device and having a reflective surface parallel to the YZ plane.

[0112] 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.

[0113] 1, 1a, 1b, 1c, 1d, 1e, 1f, 1g...Aerial image display device Dsp1, Dsp2, Dsp3, Dsp4, Dsp5, Dsp6, Dsp7, Dsp8...Display RR1, RR2, RR3, RR4, RR5, RR6, RR7...Reflector BS1, BS2, BS3, BS4, BS5, BS6, BS7...Beam splitter RS1, RS2, RS3, RS4, RS5, RS6, RS7...Reflector Wp...Wave plate PR...Polarizing film M1, M2...Mirror I1, I2, I3, I4, I5, I6, I7, I8...Aerial image I'...Virtual image

Claims

1. An aerial image display device that displays an aerial image on a first reflective surface including a first direction and a second direction intersecting the first direction, comprising: a display having a display surface facing from one end side to the other end side in the first direction, a beam splitter having a second reflective surface, and a retroreflective material having a third reflective surface facing from the other end side to one end side in the first direction, wherein at least a portion of a first outgoing light based on a display on the display surface is reflected by the second reflective surface of the beam splitter, at least a portion of the reflected first outgoing light is retroreflected by the third reflective surface of the retroreflective material, at least a portion of the retroreflected first outgoing light transmits through the beam splitter from the other end side to one end side in the first direction, at least a portion of the transmitted first outgoing light is reflected by the first reflective surface, and the aerial image is formed by at least a portion of the first outgoing light reflected by the first reflective surface.

2. The aerial image display device according to claim 1, wherein the second reflecting surface of the beam splitter is arranged so as to intersect with the first reflecting surface.

3. An aerial image display device as described in claim 1, wherein the length between the display and the beam splitter on an extension of the display is shorter than the length between the first reflecting surface and the beam splitter at the position where the aerial image is formed.

4. An aerial image display device as described in claim 1, further comprising a first mirror and a second mirror arranged to intersect with the first reflecting surface, and the display and the beam splitter are positioned so as to be sandwiched between the first mirror and the second mirror.

5. An aerial image display device as described in claim 1, further comprising: a polarizing film arranged to cover the second reflecting surface; and a wavelength plate arranged to cover the third reflecting surface, wherein the display is a polarized display that emits a first linearly polarized light, and the polarizing film reflects the first linearly polarized light and transmits a second linearly polarized light different from the first linearly polarized light.

6. An aerial image display device that displays an aerial image on a first reflecting surface including a first direction and a second direction intersecting the first direction, comprising: a display having a display surface facing from one end side to the other end side in the first direction; and a retrotransparent element, wherein at least a portion of first emitted light based on the display on the display surface is transmitted through the retrotransparent element from the other end side to one end side in the first direction, at least a portion of the transmitted first emitted light is reflected by the first reflecting surface, and the aerial image is formed by at least a portion of the first emitted light reflected by the first reflecting surface.

7. The aerial image display device according to any one of claims 1 to 6, wherein the first reflecting surface is a table top, a ceiling surface, a wall surface, or a terminal display.

Images