JP7067809B2 - Display device - Google Patents

Description

The present invention relates to a display device .

In recent years, in fields such as communication / broadcasting, entertainment, art, and medical care, aerial display technology that can display images that can be seen without wearing special glasses by using the environment and space has become available in three-dimensional space. Attention has been paid. As described above, as one of the methods for displaying an image in a three-dimensional space, an aerial display using retroreflection (Aerial Imaging by Retro-Reflection: AIRR) is known (see, for example, Non-Patent Document 1). ..

The display device 101 shown in FIG. 51 is an example of the configuration of the AIRR, and includes a light source S provided on the display D1 and the like, a half mirror 104, and a retroreflective unit 106. Of the light L1 emitted from the light source S, a part of the light L101 is reflected as the reflected light L102 by the half mirror 104. The reflected light L102 is incident on the retroreflective unit 106, is reflected by the retroreflective unit 106 in the same direction as the incident direction, is incident on the half mirror 104 as reflected light L103, is transmitted through the half mirror 104, and is transmitted to the half mirror 104. On the other hand, an aerial image I is formed at a position Q1 that is plane-symmetrical to the display D1. The user can see the aerial image I displayed in the space A (that is, the space in which the user is present with respect to the half mirror 104) from the observation direction E0 on the side opposite to the light source S with respect to the half mirror 104. Here, the aerial image I that can be observed by the user is limited to the range in which the retroreflective portion 106 can be seen from the user's viewpoint position through the half mirror 104. Even if the aerial image I is formed, the user can only observe the aerial image in a certain area Z1.

Further, in Patent Document 1, as an example of a configuration in which the number of parts is reduced, a beam dividing device placed in a passage of light from an object (light source) and light transmitted or reflected by the beam dividing device are transmitted or reflected by the beam dividing device. A display device having a retroreflective means placed in a passageway is disclosed. In the display device described in Patent Document 1, the beam dividing device is attached to an opening in an opaque surface.

Special Table No. 9-506717

H. Yamamoto, Y. Tomiyama, S, Suyama, "Floating aerial LED signage based on aerial imaging by retro-reflection (AIRR)", Optics Express, Vol. 22, No. 22, pp. 26919-26924 (2014).

However, in the display device 101 shown in FIG. 51, a part of the light L105 and L108 of the light L1 is reflected by the half mirror 104 and then incident on the display D as the reflected light L106 and L109, and the aerial image I is shown. Does not contribute to formation. That is, in the conventional display device based on AIRR, since the light 105 that does not form the aerial image I in the light L1 is included, there is a problem that the angle θ101 at which the aerial image I can be seen becomes small.

The present invention has been made to solve the above problems, and provides a display device capable of observing an image formed in the air (aerial image) from a wider angle.

The display device according to the present invention includes an S-wave emitting unit that emits S-wave polarized light and a P-wave emitting unit that emits P-wave polarized light, and emits light including the S-wave polarized light and the P-wave polarized light. A first wavelength plate that gives (π / 2) a phase difference in the electric field vibration direction of the incident light to transmit the light, and a side opposite to the display side that transmits the light incident from the display side. The first retroreflective part that retroreflects the light incident from the light, the second wavelength plate that gives a phase difference of (π / 2) in the electric field vibration direction of the incident light and transmits the light, and the incident from the display side. The display, the first wavelength plate, the first retroreflective part, the second wavelength plate, and the optical branching part are provided in this order with an optical branching portion for branching the reflected light into reflected light and transmitted light. The light that is arranged and emitted from the display passes through the first wavelength plate, the first retroreflective portion, and the second wavelength plate, enters the optical branch portion, and is reflected by the optical branch portion. The light passes through the second wavelength plate and is retroreflected by the first retroreflective unit.

The display device according to the present invention includes an S-wave emitting unit that emits S-wave polarized light and a P-wave emitting unit that emits P-wave polarized light, and emits light including the S-wave polarized light and the P-wave polarized light. A three-dimensional film having at least one of a display, a transmissive differential barrier, a transmissive parallax barrier, and a transmissive lenticular lens, and light incident from the display side is transmitted from the side opposite to the display side. The display, the three-dimensional film, and the first The retroreflective part and the optical branching part are arranged in this order, and the light emitted from the display passes through the three-dimensional film and the first retroreflective part and is incident on the optical branching part to enter the optical branching part. The light reflected by the unit is retroreflected by the first retroreflective unit.

In the display device according to the present invention, the three-dimensional film emits the S-wave polarization emitted from the display toward the first observation position, and the P-wave polarization emitted from the display is the first observation. It may be emitted toward the second observation position different from the position.

In the display device according to the present invention, the S-wave polarization or the P-wave polarization emitted from the region may be adjustable for each predetermined region in the plane of the display.

In the display device and the display method of the aerial image of the present invention, at least a part of the first light emitted from the first light source is reflected as the first reflected light by the first light branching portion, and then the first recurrence. It is reflected toward the first light branch by the reflecting portion, passes through the first light branch, and can form an aerial image. That is, since the first reflected light reaches the position where the aerial image was not formed by the conventional display device, the aerial image can be formed. Therefore, according to the present invention, it is possible to provide a display device capable of observing an aerial image from a wider angle and a method for displaying an aerial image.

It is a schematic diagram which shows the structure of the display device of 1st Embodiment which concerns on this invention. It is a side view which shows the 1st example of the structure of the retroreflection part used in the display device of 1st Embodiment which concerns on this invention. It is a side view which shows the 2nd example of the structure of the retroreflection part used in the display device of 1st Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the 2nd Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the 3rd Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the modification of the display device of 3rd Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of 4th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the 5th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the 6th Embodiment which concerns on this invention. It is a top view of the 4th display of the display device shown in FIG. It is a schematic diagram which shows the structure of the display device which is the 1st modification of the 6th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device which is the 2nd modification of the 6th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of 7th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of 8th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the 9th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device which is the 1st modification of the 9th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device which is another modification of the 9th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device which is the 2nd modification of the 9th Embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the display device of the tenth embodiment which concerns on this invention. It is a schematic diagram which shows another structure of the display device of the tenth embodiment which concerns on this invention. It is a schematic diagram which shows still another structure of the display device of the tenth embodiment which concerns on this invention. It is a schematic diagram which shows the other structure of the display device of the tenth embodiment which concerns on this invention. It is a schematic diagram which shows the other structure of the display device of the tenth embodiment which concerns on this invention. It is a schematic diagram which shows the structure of the 1st modification of the display device which concerns on this invention. It is a schematic diagram which shows the structure of the 2nd modification of the display device which concerns on this invention. It is a schematic diagram which shows the structure of the display device which is the display device which concerns on this invention, and is housed in a housing. It is a schematic diagram which shows the use example of the display device which concerns on this invention. It is a photograph of the aerial image displayed by the display device 1A of the first embodiment and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1E of the second embodiment and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1G of the third embodiment and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1G'of Example 3 and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1H of the fourth embodiment and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1K of the fifth embodiment and the direct transmitted light by the light source. It is a photograph of the aerial image displayed by the display device 1P of the sixth embodiment. It is a photograph of the aerial image displayed by the display device 1Q of the sixth embodiment. It is an emission image of the special color display used in Example 7 and Comparative Example 1. It is a photograph of an aerial image displayed by the display device CT of Comparative Example 1. It is a photograph of the aerial image displayed by the display device 1T (1) of the seventh embodiment. It is a photograph of the aerial image displayed by the display device 1T (2) of the seventh embodiment. It is a photograph of the aerial image displayed by the display device 1T (3) of the seventh embodiment. It is a photograph of the aerial image displayed by the display device 1T (4) of the seventh embodiment. It is a photograph of the aerial image displayed by the display device 1T (2) of the eighth embodiment taken on the left side in the direction facing the aerial image. It is a photograph of the aerial image displayed by the display device 1T (2) of the eighth embodiment taken in front of the direction facing the aerial image. It is a photograph of the aerial image displayed by the display device 1T (2) of the eighth embodiment taken on the right side in the direction facing the aerial image. It is a photograph of another aerial image displayed by the display device 1T (2) of the eighth embodiment taken on the left in the direction facing the aerial image. It is a photograph taken in front of another aerial image displayed by the display device 1T (2) of Example 8 in the direction facing the aerial image. It is a photograph of another aerial image displayed by the display device 1T (2) of the eighth embodiment taken on the right side in the direction facing the aerial image. It is a schematic diagram which shows the structure of the display device of Example 9. It is a photograph of the aerial image displayed before arranging the wave plate 53 in the display device of the ninth embodiment. It is a photograph of an aerial image displayed when the wave plate 53 is arranged in the display device of the ninth embodiment. It is a schematic diagram which shows the structure of the conventional display device.

Hereinafter, embodiments of the display device and the method for displaying an aerial image according to the present invention will be described with reference to the drawings. The drawings used in the following description are schematic, and the length, width, thickness ratio, etc. are not always the same as the actual ones and can be changed as appropriate.

(First Embodiment)
As shown in FIG. 1, the display device 1A of the first embodiment includes a first light source S1, a first retroreflective unit 2A, a first light branching unit 4, and a second retroreflective unit 6. There is.

The first light source S1 is, for example, an LED, but is not particularly limited. A plurality of first light sources S1 of the display device 1A of the first embodiment are arranged in parallel with the plate surface of the first display D1 and are provided so that the light emission directions are aligned with each other. The number and relative arrangement of the first light sources S1 are not particularly limited.

In the present invention, the first retroreflective unit 2 is arranged at the position P2 on the first emission axis J1 indicating the emission direction E1 of the first light L1 emitted from the first light source S1.
The first retroreflective unit 2A of the first embodiment is arranged in the emission direction E1 with reference to the first light source S1 on the first emission axis J1. The first retroreflective unit 2A is preferably arranged on the first emission axis J1 in the vicinity of the first display D1 (that is, the position PS1 of the first light source S1). The first retroreflective unit 2A may be attached to the emission direction E1 side of the first light source S1 of the first display D1 and integrated with the first display D1.

The first retroreflective unit 2A has a known retroreflective structure. Examples of the retroreflective structure of the first retroreflective unit 2A include retroreflective structures 3A and 3B including a plurality of unit structures 10 having at least one or more reflecting surfaces 12, as shown in FIGS. 2 and 3. ..

The surface 3a (that is, the surface on which light is incident) of the retroreflection structure 3A shown in FIG. 2 is formed flat. On the other hand, on the surface 3b of the retroreflective structure 3A, a plurality of triangular shapes constituting the unit structure 10 are formed so as to be adjacent to each other along the surface 3b when viewed from the side.
The light L10a incident on the surface 3a passes through the surface 2a and is incident on the reflecting surface 12a of the unit structure 10 as the light L10b. The light L10b is reflected by the reflecting surface 12a and travels toward the reflecting surface 12c of the unit structure 10 as the light L10c. In the retroreflective structure 3A, the internal angles formed by the reflective surfaces 12a and 12c of the unit structure 10 are set to a predetermined angle (that is, approximately 90 °). Therefore, the light L10c incident on the reflecting surface 12c is reflected as the light L10d in the direction parallel to the light L10b by the reflecting surface 12c, and is emitted from the surface 3a as the reflected light L10e.
In FIG. 2, the refraction from the light 10a to the light 10b and the refraction angle from the light 10d to the light 10e with the surface 3a as a boundary are omitted.

On the surfaces 3a and 3b of the retroreflective structure 3B shown in FIG. 3, a plurality of semicircular shapes constituting the unit structure 10 when viewed from the side are formed so as to be adjacent to each other along the surfaces 3a and 3b. That is, the retroreflection structure 3B is a structure in which a plurality of minute cylinders or spheres are arranged so as to be adjacent to each other along one direction.
The light L10a incident on the surface 3a passes through the surface 3a, is refracted by the surface 3a at a refraction angle corresponding to its curvature, and travels toward the reflecting surface 12a of the unit structure 10 as the light L10b. The light L10b incident on the reflecting surface 12a is reflected by the reflecting surface 12a and travels toward the surface 3a as the reflected light L10d. Since the surface 3a and the reflecting surface 12a are formed so as to form a sphere corresponding to each other, the light L10d reflected by the reflecting surface 12a is refracted by the surface 3a in a direction parallel to the light L10a and reflected from the surface 3a. It is emitted as light L10e.

According to the first retroreflective unit 2A provided with the retroreflective structures 3A and 3B, the incident angle and the emitted angle are equal, so that the light incident on the first retroreflective unit 2A has the refractive index of the material of the retroreflective structure 3A. Regardless, it is reflected in the same direction as the incident direction. The first retroreflective unit 2A is arranged so that the surface 3b side of the retroreflective structure 3A or the retroreflective structure 3B faces the first light source S1.

The material of the first retroreflective part 2A allows the first light L1 to pass through, and retroreflects the light incident on the first retroreflective part 2A from the first light branching part 4 side (that is, the opposite side of the emission direction E1). If possible, there is no particular limitation. If the first light L1 is visible light, the first light L1 can be transmitted more efficiently inside the retroreflective structures 3A and 3B, so that the material of the first retroreflective portion 2A is Examples thereof include optical glass, polycarbonate resin (PC), polymethyl methacrylate resin (PMMA) and the like. Further, a reflective substance (not shown) is provided in contact with the surface 3b side, that is, the reflective surfaces 12a and 12c. As the reflective substance, the first light L1 can be transmitted in the emission direction E1 and can reflect light (for example, light L16 or the like) incident on the first retroreflective portion 2A in the direction opposite to the emission direction E1. A substance is used, and examples thereof include a dielectric substance.

The structure and material of the first retroreflective unit 2 are not particularly limited as long as the light incident on the first retroreflective unit 2 can be reflected in the same direction as the incident direction.
For example, the first retroreflective unit 2 includes a full-corner cube, a cat-eye retroreflective material, a combination of a wrenchular lens and a reflector, and a lens in which single lenses are arranged in vertical and horizontal contact (so-called flies' eyes). A combination of a lens (lens, fly-eye lens) and a reflector, a hologram that copies the retroreflective performance, a spatial light modulator (SLM), an acoustic optical modulator (AOM), etc. Examples include digital holograms, phase conjugate mirrors, etc., which are possible and have a retroreflective function programmed. Examples of the full corner cube include known prism type reflective sheets (see, for example, http://www.yao-sangyo.co.jp/sign/prism_4090.html, etc.) and crystal grades (registered trademarks, for example, http: /). /Www.carbide.co.jp/jp/viewer/file/product/4c74f1d8ac72dfc26d1e3587c0358529.pdfsurasshu4c74f1d8ac72dfc26d1e3587c035529.

The first light branching unit 4 reflects a part of the first light L1 transmitted through the first retroreflective unit 2A as the first reflected light L2 toward the second retroreflective unit 6, and is reflected by the second retroreflective unit 6. It transmits at least a part of the reflected first reflected light L2. The first light branching unit 4 is arranged at a predetermined position on the user's observation position side with respect to the first light source S1 and the first retroreflective unit 2A. The first light branching unit 4 is, for example, a half mirror, but as described above, it reflects a part of the first light L1 and at least a part of the first reflected light L2 reflected by the first retroreflective unit 2A. It is not particularly limited as long as it can be made transparent. In addition to the half mirror, such a first light branching portion 4 includes, for example, a plate-shaped member made of acrylic or glass, a hollow body made of these materials and containing water in a hollow, a punching metal, or the like. Examples include a plate having a row of openings, a wire grid film, a reflective polarizing film, and a beam splitter generally called a beam splitter.

The second retroreflective unit 6 is arranged at a position P6 on the second emission axis J2 indicating the emission direction E2 of the first reflected light L2 reflected by the first light branching unit 4. The position P6 of the second retroreflective unit 6 is in the emission direction E2, and takes into consideration the position PS1 of the first display D1, the position P2 of the first retroreflective unit 2A, and the position P4 of the first optical branching unit 4. One reflected light L2 is appropriately set at a position where it can be incident.

The second retroreflective unit 6 has a known retroreflective structure. That is, examples of the structure and material of the second retroreflective unit 6 include the same structure and material as the first retroreflective unit 2 described above, but the light incident on the second retroreflective unit 6 is directed in the same direction as the incident direction. As long as it can be reflected to, it is not particularly limited. However, since it is not necessary for the first reflected light L2 to be transmitted in the second retroreflective unit 6, for example, when the retroreflective structures 3A and 3B are adopted, as a reflective substance provided on the surface 3b side, that is, the reflective surfaces 12a and 12c. In addition to the above-mentioned dielectric material and the like, for example, aluminum, gold, silver and the like can be mentioned.

In the display device 1A of the first embodiment, of the first light L1 emitted from the first light source S1, a part of the light L11 is used as reflected light L12 (first reflected light L2) by the first light branching portion 4. Be reflected. The reflected light L12 is incident on the second retroreflective unit 6, reflected by the second retroreflective unit 6 in the same direction as the incident direction, is incident on the first light branch portion 4 as the reflected light L13, and is the first light branch. It passes through the portion 4 and forms an aerial image I at a position Q1 symmetric with the first light source S1 with respect to the plate surface (that is, the reflecting surface) of the first light branching portion 4.
Further, of the first light L1, the light L15 is reflected by the first light branching portion 4 and then is incident on the first retroreflective portion 2A as reflected light L16 (first reflected light L2) to be first retroreflected. A position Q1 that is reflected by the portion 2A in the same direction as the incident direction, passes through the first light branch portion 4, and is symmetric with respect to the plate surface (that is, the reflection surface) of the first light branch portion 4 with respect to the first light source S1. Form an aerial image I.
Then, for example, the light L18 (first light L1) emitted from the first light source S1 arranged at one end of the first display D1 is reflected by the first light branching portion 4, and then the reflected light L19 ( It is incident on the first retroreflective part 2A as the first reflected light L2), is reflected by the first retroreflective part 2A in the same direction as the incident direction, passes through the first light branch part 4, and is transmitted by the first light branch part 4. An aerial image I is formed at a position Q2 symmetrical to the first light source S1 with respect to the plate surface (that is, the reflecting surface).

According to the display device 1A of the first embodiment described above, the user can use the conventional display device in addition to a certain area Z1 in the space A (that is, the space where the user is with respect to the first optical branch portion 4). Then, the aerial image I can be observed in the region Z2 where the image could not be observed. Therefore, the user can observe the aerial image I displayed in the region Z1 and the region Z2 from the observation direction E0 on the side opposite to the first light source S1 with respect to the first optical branch portion 4. As a result, the angle θ1A at which the aerial image I can be seen on the display device 1A can be increased. Further, as can be seen with reference to FIG. 1, substantially all of the first light L1 emitted from the first light source S1 contributes to the formation of the image I regardless of the position of the first light source S1 in the first display D1. Therefore, it is possible to improve the brightness of the aerial image I.

(Second embodiment)
Next, the display device 1B of the second embodiment according to the present invention will be described. In the components of the display device 1B of the second embodiment shown in FIG. 4, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 4, the display device 1B includes a first light source S1, a first retroreflective unit 2A, a first optical branching unit 4 arranged so as to face the first retroreflective unit 2A, and first. It includes a wave plate 21, a second wave plate 22, and a first polarization branching portion 25.
Further, in the display device 1B, the first reflected light L2 is configured to be incident on the first retroreflective portion 2A.

The arrangement of the first retroreflective unit 2A is particularly limited as long as the user can see the aerial image I formed by the first retroreflective unit 2A and the first light source S1 (that is, the directly transmitted light) as one. Not done. Specifically, let V be the distance (that is, the observation distance) between the position of the user's eye and the aerial image I, and let T be the distance between the position PS1 of the light source S1 and the position P2 of the first retroreflective unit 2A. It is preferable that T <(V / 50).

The first wave plate 21 is arranged between the first light source S1 on the first emission axis J1 and the first retroreflective unit 2. The second wave plate 22 is arranged in the emission direction E1 of the first light L1 with reference to the first retroreflective portion on the first emission axis J1.
The first wave plate 21 and the second wave plate 22 are configured to give a phase difference of (π / 2) in the electric field vibration direction of the light incident on each, and are so-called λ / 4 plates.

The first polarization branching portion 25 is arranged between the first light source S1 on the first emission axis J1 and the first wave plate 21. Therefore, in the display device 1B, the first display D1 including the first light source S, the first polarization branching portion 25, the first wave plate 21, the first retroreflecting portion 2A, along the emission direction E1 of the first light L1. The second wave plate 22 and the first light branch portion 4 are arranged so as to face each other. Of these, the first display D1, the first polarization branching portion 25, the first wavelength plate 21, the first retroreflective portion 2A, and the second wavelength plate 22 are preferably extremely close to each other and are in contact with each other. It may be integrated.
The first polarization branching unit 25 is configured to be able to transmit P-polarization and reflect S-polarization, and is, for example, a reflection type polarization beam splitter.

In the display device 1B of the second embodiment, of the first light L1 emitted from the first light source S, only the first light L1 of P polarization passes through the first polarization branch portion 25 and is along the emission direction E1. It emits light, passes through the first wave plate 21, the first retroreflecting unit 2, and the second wave plate 22 in this order to become S-polarized first light L1 and emits light. A part of the S-polarized first light L1 emitted from the second wave plate 22 is reflected as the first reflected light L2 by the first light branch portion 4. The S-polarized first reflected light L2 passes through the second wavelength plate 22, is incident on the second retroreflective unit 6, is reflected by the second retroreflective unit 6 in the same direction as the incident direction, and is again reflected on the second wavelength plate. It passes through 22 and is incident on the first light branch portion 4 as P-polarized reflected light L3, and at the same time, it is transmitted through the first light branch portion 4 and with respect to the plate surface (that is, the reflective surface) of the first light branch portion 4. Therefore, the aerial image I is formed at the position Q1 symmetrical to the first light source S1.

According to the display device 1B of the second embodiment described above, the user can observe the aerial image I from the observation direction E0 on the side opposite to the first light source S1 with respect to the first optical branching portion 4. As a result, the angle θ1B at which the aerial image I can be seen in the display device 1B of the second embodiment covers the entire region of the first light source S1 arranged on the first display D1, and the angle θ1B can be increased. .. Further, as can be seen with reference to FIG. 4, an aerial image I is formed of substantially all of the P-polarized first light L1 emitted from the first light source S1 regardless of the position of the first light source S1 in the first display D1. Can be contributed to.

Further, according to the display device 1B of the second embodiment, the first retroreflecting unit 2 is provided in the emission direction E1 of the first light L1 with respect to the first light source S1 and the first display D1, and the first light branching unit 2 is provided. By using a reflective polarizing film, a polarizing plate, a half mirror provided with a polarizing film, or the like as 4, the transmitted light is directly blocked by the first light branching portion 4, so that the user can use the first light source S and the first light source. The display D1 (that is, the directly transmitted light) cannot be seen. Therefore, it is possible to prevent the visibility of the aerial image I from being lowered due to the mixture of the aerial image I and the first light source S1.

Further, according to the display device 1B of the second embodiment, the second retroreflective unit 6 is omitted, the first light source S1, the first polarization branching unit 25, and the first along the emission direction E1 of the first light L1. The wave plate 21, the first retroreflective unit 2A, the second wave plate 22, and the first light branching unit 4 can be arranged, so that the entire device can be made compact and space can be saved.

(Third embodiment)
Next, the display device 1C of the third embodiment according to the present invention will be described. In the components of the display device 1C of the third embodiment shown in FIG. 5, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 5, the display device 1C includes a first light source S1, a first retroreflecting unit 2A, a first light branching unit 4, a first wave plate 21, a second wave plate 22, and a first. The polarization branch 25, the second light source S2, the second retroreflector 7, the second light branch 5, the third wave plate 23, the fourth wave plate 24, the second polarization branch 26, and the like. It is equipped with.

The second light source S2 is, for example, an LED like the first light source S1, but is not particularly limited. Further, a plurality of second light sources S2 of the display device 1C of the third embodiment are arranged in parallel with the plate surface of the second display D2, and are provided so that the light emission directions are aligned with each other. The number of the second light sources S2 is not particularly limited. However, the second light source S2 is arranged so that the second light L21 can be emitted in the direction E3 (hereinafter referred to as the emission direction E3) opposite to the emission direction E2 of the first reflected light L2.

The second retroreflective unit 7 is arranged at a position P7 on the third emission axis J3 indicating the emission direction E3 of the second light L21, is capable of retroreflecting the first reflected light L2, and is at least a part of the second light L21. Is configured to be transparent. Examples of the structure and material of the second retroreflective unit 7 include the same structure and material as the first retroreflective unit 2 described above.

The second light branching portion 5 transmits a part of the second light L21 transmitted through the second retroreflective part 7, and at least a part of the second light L21 transmitted through the second retroreflective part 7 is the second reflected light. It reflects as L22.

The third wave plate 23 is arranged between the second light source S2 on the third emission axis J3 and the second retroreflective unit 7. The fourth wave plate 24 is arranged at a position in the emission direction E3 of the second light L21 with reference to the second retroreflective portion 7 on the third emission axis J3.
Similar to the first wave plate 21 and the second wave plate 22, the third wave plate 23 and the fourth wave plate 24 give a phase difference of (π / 2) in the electric field vibration direction of the light incident on each of them. It is a so-called λ / 4 plate.

The second polarization branching portion 26 is arranged between the second light source S2 on the third emission axis J3 and the third wave plate 23. Therefore, in the display device 1C, along the emission direction E3 of the second light L21, the second display D2 including the second light source S2, the second polarization branching portion 26, the third wavelength plate 23, the second retroreflecting portion 7, The fourth wave plate 24 and the second light branching portion 5 are appropriately arranged. Of these, the second display D2, the second polarization branching portion 26, the third wavelength plate 23, the second retroreflective portion 7, and the fourth wavelength plate 24 are preferably extremely close to each other and are in contact with each other. It may be integrated.
The second polarization branching portion 26 is configured to be able to reflect P polarization and transmit S polarization, and is, for example, a reflection type polarization beam splitter.

As can be seen with reference to FIG. 5, the display device 1C of the third embodiment is the display device 1B of the second embodiment, the first display D1 including the first light source S1, the first polarization branching portion 25, and the first wavelength. The configuration including the plate 21, the first retroreflective portion 2A, and the second wave plate 22 and the relative position with the first optical branching portion 4 are set to the first display D1 and the first retroreflective portion in the display device 1A of the first embodiment. The relative positions of the portion 2A and the first optical branching portion 4 are the same, and the same configurations are arranged so as to face each of these configurations.

In the display device 1C of the third embodiment, of the first light L1 emitted from the first light source S1, only the first light L1 of P polarization passes through the first polarization branch portion 25 and is along the emission direction E1. It emits light, passes through the first wave plate 21, the first retroreflecting unit 2, and the second wave plate 22 in this order to become S-polarized first light L1 and emits light. A part of the S-polarized first light L1 emitted from the second wave plate 22 is reflected as the first reflected light L2 by the first light branch portion 4. The S-polarized first reflected light L2 passes through the second wavelength plate 22, is incident on the second retroreflective unit 6, is reflected by the second retroreflective unit 6 in the same direction as the incident direction, and is again reflected on the second wavelength plate. It passes through 22 and is incident on the first light branch portion 4 as P-polarized reflected light L3, and at the same time, it is transmitted through the first light branch portion 4 and with respect to the plate surface (that is, the reflective surface) of the first light branch portion 4. Therefore, the aerial image I1 is formed at the position Q1 symmetrical to the first light source S1.

On the other hand, of the second light L21 emitted from the second light source S2, only the S-polarized second light L21 passes through the second polarization branching portion 26 and is emitted along the emission direction E3, and is emitted along the emission direction E3. , The second retroreflecting unit 7 and the fourth wave plate 24 are transmitted in this order to become the first light L21 of P polarization, which is emitted. A part of the P-polarized first light L1 emitted from the fourth wave plate 24 is reflected as the first reflected light L2 by the second light branching portion 5. The P-polarized first reflected light L2 passes through the fourth wavelength plate 24, is incident on the second retroreflective unit 7, is reflected by the second retroreflective unit 7 in the same direction as the incident direction, and is again reflected on the fourth wavelength plate. It passes through 24 and is incident on the second light branching portion 5 as S-polarized reflected light L3, and at the same time, it is transmitted through the second light branching portion 5 with respect to the plate surface (that is, the reflecting surface) of the second light branching portion 5. Therefore, an aerial image I2 is formed at a position Q10 symmetrical to the second light source S2.

According to the display device 1C of the third embodiment described above, the user can see the aerial image I1 (for example, a character image) from the observation direction E0 on the side opposite to the first light source S1 with respect to the first light branch portion 4. "A") can be observed. On the other hand, the user can observe the aerial image I2 (for example, the character image "B") from the observation direction E10 on the side opposite to the second light source S2 with respect to the second light branch portion 5. As described above, according to the display device 1C of the third embodiment, the aerial images I1 and I2 can be made into a multi-view.
In the arrangement described above in which the polarization directions of the transmitted light in the first light branch portion 4 and the second light branch portion 5 are orthogonal to each other, the second light source S2 and the second display D2 are behind the aerial image I1 from the observation direction E0. (That is, the directly transmitted light) can be observed through the first light branch portion 4, and the first light source S1 and the first display D1 (that is, the directly transmitted light) are secondly branched from the observation direction E10 behind the aerial image I10. It can be observed through the part 5. That is, the two layers of the aerial image and the directly transmitted light as the background are multi-viewed.
On the other hand, when the light is arranged so that the polarization directions of the transmitted light in the first light branch 4 and the second light branch 5 are parallel to each other, for example, the second light branch 5 is arranged so as to transmit only the P polarization component. Then, in the case of arranging the second polarization branching portion 26 so as to transmit only the P polarization component correspondingly, the first light source S1 and the first display D1 (that is, the directly transmitted light) and the second light source are arranged. The S2 and the second display D2 (that is, the direct transmitted light) are not observed, only the aerial image I1 is observed in the observation direction E1, and only the aerial image I10 is observed in the observation direction E10. ..
FIG. 5 shows multi-viewing in two directions, but by installing the display device 1B so as to face each other in each observation direction, multi-viewing in three or more directions is possible.
The angle at which the aerial images I1 and I2 can be seen extends over the entire region of the first light source S1 arranged on the first display D1 and the entire region of the second light source S2 arranged on the second display D2. Can be made larger. Further, regardless of the position of the first light source S1 in the first display D1 or the position of the second light source S2 in the second display D2, the P-polarized first light L1 and the second light source S2 emitted from the first light source S1 Almost all of the emitted S-polarized second light L21 can contribute to the formation of the aerial images I1 and I2.

Further, according to the display device 1C of the third embodiment, a reflective polarizing film, a polarizing plate, a half mirror provided with a polarizing film, or the like is used as the first light branching portion 4 and the second light branching portion 5. Since the directly transmitted light is blocked by the first light branching portion 4 and the second light branching portion 5, the user cannot see the first light source S and the first display D1 (that is, the directly transmitted light). Therefore, it is possible to prevent a decrease in the visibility of the aerial image I due to the mixture of the aerial image I and the first light source S1 and the second light source S2.

In the display device 1D, which is a modification of the display device 1C of the third embodiment, as shown in FIG. 6, the first light source S1, the first retroreflecting unit 2, the first light branching unit 4, and the first of the display device 1C are shown. A structure including a wave plate 21 and a second wave plate 22, a first polarization branching portion 25, a second light source S2, a second retroreflecting portion 7, a third wave plate 23, a fourth wave plate 24, and a second. It has a configuration including a polarization branching portion 26 and a configuration in which the polarization branching portions 26 are brought close to each other. Therefore, in the display device 1D, the second optical branch portion 5 is omitted.

According to the display device 1D which is a modification of the third embodiment, the angle at which the aerial image I can be seen is the first light source S1 arranged in the first display D1 or the second light source arranged in the second display D2. It covers the entire area of S2 and can be increased. Further, by installing the first polarization branching portion 25 so that the direct light of the first display D1 passes through the first light branching portion 4, the user can use the second light source S2 with respect to the first light branching portion 4. From a certain direction E0 on the opposite side, a background (for example, the character image “U”) due to direct light can be seen behind the aerial image I3 (for example, the character image “O”). As described above, according to the display device 1D which is a modification of the third embodiment, it is possible to achieve two layers of the aerial image I and the direct image.

(Fourth Embodiment)
Next, the display device 1E according to the fourth embodiment of the present invention will be described. In the components of the display device 1E of the fourth embodiment shown in FIG. 7, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 7, the display device 1E includes a first light source S1, a first retroreflective unit 2, a first light branching unit 4, a second light source S2, and a second retroreflective unit 7. ing. In the configuration of the display device 1A, the display device 1E is provided with the second retroreflective unit 7 at the position of the second retroreflective unit 6 and the second display D2 is arranged in the emission direction E2 of the second reflected light L2. ..

In the display device 1E of the fourth embodiment, a part of the first light L1 emitted from the first light source S1 is reflected as the first reflected light L2 by the first light branching portion 4. The first reflected light L2 is incident on the second retroreflective unit 6, is reflected by the second retroreflective unit 6 in the same direction as the incident direction, is incident on the first light branch portion 4 as reflected light L3, and is first. It passes through the optical branching portion 4 and forms an aerial image I1 at a position Q1 symmetric with the first light source S1 with respect to the plate surface (that is, the reflecting surface) of the first light branching portion 4.
A part of the second light L21 emitted from the second light source S2 is also reflected as the first reflected light L2 by the first light branching portion 4. The first reflected light L2 is incident on the second retroreflective unit 6, is reflected by the second retroreflective unit 6 in the same direction as the incident direction, is incident on the first light branch portion 4 as reflected light L3, and is first. It passes through the optical branch portion 4 and forms an aerial image I2 at a position Q10 symmetric with the second light source S2 with respect to the plate surface (that is, the reflective surface) of the first optical branch portion 4.

According to the display device 1E of the fourth embodiment described above, the user can see the aerial image I1 and the display D2 from a certain direction E0 on the opposite side of the first light branch portion 4 from the first light source S1. Both of the second light source S2 (that is, the directly transmitted light) can be seen. On the other hand, the user can see both the aerial image I2 and the first light source S1 (that is, the direct transmitted light) of the display D1 from the observation direction E10 opposite to the second light source S2 with respect to the second light branch portion 5. Can be seen. As described above, according to the display device 1C of the third embodiment, it is possible to achieve multi-view by combining the aerial image I and the displays D1 and D2 (that is, the light sources S1 and S2).
The angle θ1E at which the aerial images I1 and I2 can be seen extends over the entire region of the first light sources S1 and S2 arranged on the first displays D1 and D2, respectively, and becomes large. Further, regardless of the position of the first light source S1 in the first display D1 or the position of the second light source S2 in the second display D2, the first light L1 and the second light source S2 emitted from the first light source S1 are emitted. Almost all of the second light L21 can contribute to the formation of the aerial images I1 and I2.

(Fifth Embodiment)
Next, the display device 1F of the fifth embodiment according to the present invention will be described. In the components of the display device 1F of the fifth embodiment shown in FIG. 8, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 8, the display device 1F includes a first light source S1, a first retroreflective unit 2B, a first light branching unit 4, and a second retroreflective unit 6.

In the display device 1F, the first retroreflective unit 2B is the opposite of the emission direction E1 with respect to the first light source S1 on the first emission axis J1 indicating the emission direction E1 of the first light L1 emitted from the first light source S1. It is placed on the side.
The second retroreflective unit 6 is arranged so as to connect the outer peripheral edge of the first retroreflective unit 2B and the outer peripheral edge of the first optical branching unit 4.
However, since it is not necessary for the first retroreflective unit 2B to transmit the first light L1 and the first reflected light L2, for example, when the retroreflective structures 3A and 3B are adopted, the surface 3b side, that is, the reflecting surfaces 12a and 12c Examples of the reflective material provided include, for example, aluminum, gold, silver, and the like, in addition to the above-mentioned dielectric material and the like. That is, the first retroreflective unit 2B and the second retroreflective unit 6 may have a similar retroreflective structure.

In the above arrangement, the first light source S1 is arranged in the space X surrounded by the first retroreflective unit 2B, the first light branching unit 4, and the second retroreflective unit 6.
At the third display D3 having the first light source S1, that is, at the position PS1 of the first light source S1, the non-arranged portion NS of the first light source S1 is made capable of transmitting the first light and the first reflected light L2. Examples of such a third display D3 include what is called a transparent display or a see-through display. Specifically, for example, a liquid crystal display with transparent pixels without a color filter or an organic EL is used to partially make the display transparent. Examples thereof include a non-arranged portion NS that can be seen through, or a panel (so-called ribbon LED or the like) composed of a plurality of LEDs arranged in a stripe shape at intervals from each other.

In the display device 1F of the fifth embodiment, a part of the first light L1 emitted from the first light source S1 is reflected as the first reflected light L2 by the first light branching portion 4. The first reflected light L2 is incident on the first retroreflective unit 2B, is reflected by the first retroreflective unit 2B in the same direction as the incident direction, and partially passes through the non-arranged portion NS of the third display D3. While incident on the one light branch portion 4, it passes through the first light branch portion 4 and is in the air at a position Q1 symmetric with the first light source S1 with respect to the plate surface (that is, the reflection surface) of the first light branch portion 4. Form image I.
Further, among the first light L1, the first light L18 incident on the first light branch portion 4 at a relatively small incident angle is reflected by the first light branch portion 4 and then reflected light L28 (first reflected light). As L2), it is incident on the second retroreflective part 6, reflected by the second retroreflective part 6 in the same direction as the incident direction, passes through the first light branch part 4, and is transmitted through the first light branch part 4 (that is, the plate surface of the first light branch part 4 (that is,). , Reflective surface), the aerial image I is formed at the position Q1 symmetrical to the first light source S1.

According to the display device 1F of the fifth embodiment described above, the user can observe the aerial image I from a certain direction E0 on the opposite side of the first light source S1 with respect to the first optical branching portion 4. Since the angle at which the aerial image I can be seen on the display device 1F extends over substantially the entire plate surface of the first optical branching portion 4, it can be made larger than that of a conventional display device or the like. Further, as can be seen with reference to FIG. 8, substantially all of the first light L1 emitted from the first light source S1 contributes to the formation of the aerial image I regardless of the position of the first light source S1 in the first display D1. Therefore, it is possible to improve the brightness of the aerial image I.

(Sixth Embodiment)
Next, the display device 1G according to the sixth embodiment of the present invention will be described. In the components of the display device 1G of the sixth embodiment shown in FIG. 9, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 9, the display device 1G includes a fourth display D4 including a first light source S1 and a first retroreflective unit 2C, a first optical branching unit 4, and a second retroreflective unit 6. I have.
Further, in the display device 1G, the first reflected light L2 is configured to be incident on the first retroreflective portion 2C.

In the display device 1G, the fourth display D4 is arranged between the first light source S1 arranged at intervals from each other on the surface 35a of the substrate 35 and between the first light sources S1 (that is, the first light source S1 is not arranged). The first retroreflecting unit 2C is arranged in the unit NS). With such a configuration, the first retroreflective unit 2C is arranged at the position P2 on the first emission axis J1 indicating the emission direction E1 of the first light L1 emitted from the first first light source S1 and the first light source S1. Has been done. That is, at the same positions PS1 and P2, as shown in FIG. 10, the plurality of light sources S1 and the first retroreflective unit 2C are arranged in a spatial division.
Since it is not necessary for the first retroreflective unit 2C to transmit the first light L1 and the first reflected light L2, for example, when the retroreflective structures 3A and 3B are adopted, the surface 3b side, that is, the reflecting surfaces 12a and 12c Examples of the reflective material provided include, for example, aluminum, gold, silver, and the like, in addition to the above-mentioned dielectric material and the like.

In the display device 1G of the sixth embodiment, as shown in FIG. 9, a part of the first light L1 emitted from the first light source S1 is reflected as the first reflected light L2 by the first light branch portion 4. .. The first reflected light L2 incident on the first retroreflective part 2C is reflected by the first retroreflective part 2C in the same direction as the incident direction, passes through the first light branch part 4, and is a plate of the first light branch part 4. An aerial image I is formed at a position Q1 symmetrical to the first light source S1 with respect to a surface (that is, a reflective surface).
Further, among the first light L1, the first light L18 incident on the first light branch portion 4 at a relatively small incident angle is reflected by the first light branch portion 4 and then reflected light L28 (first reflected light). As L2), it is incident on the second retroreflective part 6, reflected by the second retroreflective part 6 in the same direction as the incident direction, passes through the first light branch part 4, and is transmitted through the first light branch part 4 (that is, the plate surface of the first light branch part 4 (that is,). , Reflective surface), the aerial image I is formed at the position Q1 symmetrical to the first light source S1.

According to the display device 1G of the sixth embodiment described above, the user can observe the aerial image I from a certain direction E0 on the opposite side of the first light source S1 with respect to the first optical branching portion 4. Since the angle at which the aerial image I can be seen on the display device 1G extends over substantially the entire plate surface of the first optical branching portion 4, it can be made larger than that of a conventional display device or the like. Further, as can be seen with reference to FIG. 9, substantially all of the first light L1 emitted from the first light source S1 contributes to the formation of the aerial image I regardless of the position of the first light source S1 in the fourth display D4. Therefore, it is possible to improve the brightness of the aerial image I.

In the display device 1H, which is the first modification of the display device 1G of the sixth embodiment, as shown in FIG. 11, the first optical branch portion 4 is the fourth display D4 (that is, the first light source S1 and the first retroreflection). It is arranged so as to be inclined with respect to the surface of the portion 2C) at approximately 45 °.

According to the display device 1H which is the first modification of the sixth embodiment, it is possible to obtain the same action and effect as the display device 1G of the sixth embodiment, and further, the aerial image I is displayed on the surface of the fourth display D4. , Can be formed in directions substantially orthogonal to each other.
The angle formed by each surface of the first optical branch portion 4 and the fourth display D4 is not limited to approximately 45 ° and can be set to any angle, and the aerial image I is placed at a position corresponding to the angle. It is formed.

As shown in FIG. 12, the display device 1K, which is a second modification of the display device 1G of the sixth embodiment, includes a polarizing plate 40 in addition to the configuration of the display device 1H. However, the first retroreflective unit 2C maintains a relative relationship spatially divided with the first light source S1 in the horizontal direction, and the emission direction of the first light L1 with reference to the first light source S1 on the first emission axis J1. It is arranged at the position P2 of E1. The polarizing plate 40 is arranged between the first light source S1 on the first emission axis J1 and the first retroreflective portion 2C.

In the display device 1K which is the second modification of the sixth embodiment, only the predetermined polarization of the first light L1 emitted from the first light source S1 is transmitted through the polarizing plate 40, and the first light is transmitted through the polarizing plate 40. The light L1 is reflected as the first reflected light L2 by the first light branching portion 4. The first reflected light L2 incident on the first retroreflective part 2C is reflected by the first retroreflective part 2C in the same direction as the incident direction, passes through the first light branch part 4, and is a plate of the first light branch part 4. An aerial image I is formed at a position Q1 symmetrical to the first light source S1 with respect to a surface (that is, a reflective surface).

According to the display device 1K which is the second modification of the sixth embodiment, the same operation and effect as the display device 1G which is the first modification of the sixth embodiment can be obtained. Further, according to the display device 1K which is the second modification of the sixth embodiment, the polarizing plate 40 is provided, the reflective polarizing film is provided as the first light branching portion 4, and the polarizing film is provided on the polarizing plate and the half mirror. Since the directly transmitted light is blocked by the first light branching portion 4 by using a thing or the like, the user cannot see the first light source S1 (that is, the directly transmitted light) and the fourth display D4. Therefore, it is possible to prevent the visibility of the aerial image I from being lowered due to the mixture of the aerial image I and the first light source S1.
Also in the display device 1G of the sixth embodiment shown in FIG. 9, the first retroreflective unit 2C is located at the position P2 in the emission direction E1 of the first light L1 with reference to the first light source S1 on the first emission axis J1. If the polarizing plate 40 is arranged between the first light source S1 on the first emission axis J1 and the first retroreflective unit 2C, the directly transmitted light is blocked as described above, and only the aerial image I is displayed. Observed.

(Seventh Embodiment)
Next, the display device 1V according to the seventh embodiment of the present invention will be described. In the components of the display device 1V of the seventh embodiment shown in FIG. 13, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 13, the display device 1V includes a first display D1 provided with a first light source S1, a first light branching unit 4, and a first retroreflective unit 2A.

In the display device 1V, the first retroreflective unit 2A is arranged at a position on the second reflection axis J2 indicating the emission direction E2 of the first reflected light L2.
Further, the first light branch portion 4 is convex from the outer peripheral edge toward the center to the side opposite to the side where the first light source S1 and the first retroreflective portion 2A are arranged with respect to the first light branch portion 4. It is curved like a shape.

According to the display device 1V of the seventh embodiment described above, the user is in the space A (that is, the space where the user is with respect to the first optical branch portion 4) as in the display device 1A of the first embodiment. The aerial image I can be observed. Further, according to the display device 1V of the seventh embodiment, it is not necessary to use the second retroreflective unit 6, and the configuration of the device can be simplified as compared with the display device 1A of the first embodiment. Further, in the display device 1V of the seventh embodiment, the aerial image I can be easily arranged at a substantially right angle to the tangent line passing through the apex of the first optical branch portion 4 that curves. As a result, when the first light source S1 and the first retroreflective unit 2A are removed from the observation direction E0 and the aerial image I is viewed from the observation direction E0, the virtual images of the first light source S1 and the first light source S1 cannot be seen. This makes it easier to see the aerial image I.

(Eighth embodiment)
Next, the display device 1W according to the eighth embodiment of the present invention will be described. In the components of the display device 1W of the eighth embodiment shown in FIG. 14, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 14, the display device 1W includes a first display D1 provided with a first light source S1, a first wave plate 21, a first retroreflective unit 2A, a first reflector 50A, and a first light. A branch portion 4 and a second reflector 50B are provided.

In the display device 1W, the first wave plate 21 is from the side end portion (one side portion of the first light source) e1 of the first display D1 along the first emission axis J1 indicating the emission direction E1 of the first light L1. Is extended. The first retroreflective unit 2A is provided along the first wave plate 21 on the side of the first wave plate 21 opposite to the side facing the first display D1. The first reflector 50A extends from the side end portion (the other side portion of the first light source) e2 of the first display D1 along the first emission axis J1. The first reflector 50A corresponds to, for example, a known total reflection mirror or the like, but is not particularly limited as long as it can reflect the first light L1. The first optical branching portion 4 is arranged so as to connect between the tip portion e3 of the first wavelength plate 21 and the tip portion e4 of the first reflector plate 50A.

The second reflector 50B extends from the tip e4 of the first reflector 50A in the same direction as the extension direction of the first reflector 50A with the first light branch portion 4 interposed therebetween, and the second reflector 50A and the first reflector 50A. Is flush. Further, the second reflector 50B reflects at least a part of the first reflected light L2 reflected by the first retroreflective unit 2A, and transmits the other part. The second reflector 50B corresponds to, for example, a known half mirror or the like, but is not particularly limited as long as it can reflect the first reflected light L2. The second reflector 50B may be a total reflection mirror that reflects all the first reflected light L2 reflected by the first retroreflective unit 2A. Further, the second reflector 50B may be a transparent plate (such as a desk mat made of glass) as long as it reflects at least a part of the light of the first reflected light L2. For example, when a desk mat is used as the second reflector 50B, the aerial image I appears to float on the desk mat while the wood grain of the desk can be seen.

In the display device 1W of the eighth embodiment described above, among the first light L1 emitted from each of the first light sources S1 of the first display D1, the one directed to the first reflector 50A is the first reflector 50A. Is further reflected toward the first wavelength plate 21 by the first light branching portion 4 made of a reflective polarizing plate or the like. One of the P-polarized or S-polarized light of the first light L1 is transmitted through the first wave plate 21, is retroreflected as the first reflected light L2 by the first retroreflecting unit 2A, and is transmitted through the first light branching unit 4. .. The first reflected light L2 transmitted through the first light branch portion 4 is reflected as retroreflected light (reflected light) L13 by the second reflecting plate 50B, and the first reflected light L2 directly irradiated from the first retroreflecting portion 2A. Together with form an aerial image I. Further, as shown in FIG. 14, a virtual image of the first display D1 is generated on the opposite side of the first display D1 with the first reflectors 50A and 50B interposed therebetween.

Therefore, according to the display device 1W of the eighth embodiment, the user is in the space A (that is, the space where the user is with respect to the first optical branch portion 4) as in the display device 1A of the first embodiment. The aerial image I can be observed. For example, if the first reflector 50A and the second reflector 50B are installed on a table or the like, an aerial image I that rises substantially vertically from the above-mentioned table can be obtained, and the aerial image I can be easily observed. Further, if a half mirror is used as the second reflector 50B and a transparent table is used, a virtual image can be observed at the same time as the aerial image I.

(Ninth Embodiment)
Next, the display device 1P of the ninth embodiment according to the present invention will be described. In the components of the display device 1P of the ninth embodiment shown in FIG. 15, the same components as the components of the display device 1A of the first embodiment shown in FIG. 1 and the like are designated by the same reference numerals. The explanation is omitted.

As shown in FIG. 15, the display device 1P includes a first light source S1, a first light branching unit 4A, a second light branching unit 4B, and a first retroreflective unit 2A.

In the display device 1P, the first optical branch portion 4A and the second optical branch portion 4B are arranged so as to face each other with the first light source S1 interposed therebetween. In other words, the first light source S1 is arranged between the first optical branch portion 4A and the second optical branch portion 4B arranged so as to face each other. The emission portion (not shown) of the first light source S1 is directed to the space formed between the first light branch portion 4A and the second light branch portion 4B. The first light branch portion 4A and the second light branch portion 4B reflect at least a part of the first light L1 as the first reflected light L2 and reflect at least a part of the first reflected light L2. The first retroreflective portion 2A is provided on the surface of the second optical branch portion (one optical branch portion) 4B opposite to the surface (side) facing the first optical branch portion 4A.

In the display device 1P of the ninth embodiment, the first light L1 emitted from the first light source S1 passes through the space formed between the first light branch portion 4A and the second light branch portion 4B, and the first light branch is formed. It hits the portion 4A or the second optical branch portion 4B and transmits. When the first light L1 is irradiated to the first retroreflecting portion 2A, it is returned to the first light source S1 side as the retroreflected light 13 in the direction along the surface of the second light branching portion 4B. As a result, a plurality of aerial images I are formed at positions facing the first light source S1 with the first light branch portion 1A interposed therebetween in a direction substantially orthogonal to the surface of the first light branch portion 1A.

A virtual image is formed on the virtual line L113 in which the light L111 reflected by the second light branching portion 4B is extended toward the first retroreflective portion 2A. That is, a plurality of virtual images are formed at positions facing the first light source S1 with the second light branch portion 1B interposed therebetween.

Therefore, according to the display device 1P of the ninth embodiment, the user is provided with the space A (that is, the first light source S1 with respect to the first optical branch portion 4) as in the display device 1A of the first embodiment. A plurality of aerial images I can be observed in the space on the side opposite to the one on the opposite side. As a result, a multi-stage aerial image I can be easily formed by using the display device 1P, and the range of application development of the display device 1P is expanded.

FIG. 16 shows a display device 1Q which is a first modification of the display device 1P of the ninth embodiment. The display device 1Q is a display device 1P in which the second light source S2 is arranged at intervals from the first light source S1 in the space formed between the first light branch portion 4A and the second light branch portion 4B. Is. The exit portion (not shown) of the second light source S2 is directed to the space formed between the first light branch portion 4A and the second light branch portion 4B, and the direction in which the exit portion of the second light source S2 is directed. It is directed in the opposite direction. In other words, the display device 1Q connects the display device 1N to the first light source S1 side of the display device 1P while inverting the direction orthogonal to the surfaces of the first optical branch portion 4A and the second optical branch portion 4B. It is a thing.

According to the display device 1Q of the first modification of the display device 1P of the ninth embodiment, by using the first light source S1 and the second light source S2, an aerial image I is generated from each light source, and the aerial image I The number can be easily increased. The number of aerial images I can be further increased by utilizing the virtual images of each light source.

In the display device 1P, the first retroreflective part 2A is in contact with the second light branching part 4B, but as in the display device 1P'shown in FIG. 17, the first retroreflective part 2A is the second light branching part 4B. It may be arranged at a predetermined interval with respect to the light. As described above, the display device 1P has a degree of freedom in arranging the components. Further, in the display device 1P, both sides of one transparent acrylic plate or transparent glass plate can be used as 4A and 4B. For example, if the LED is arranged on the sash of the glass window and the curtain of the retroreflective sheet is attached to the glass window, the multiplexed aerial image I can be observed from the outside. Further, by arranging another retroreflective part on the first light branching part 4A side at a place that does not interfere with the observation of the aerial image I, the aerial image I can be formed also for the light ray L111.

FIG. 18 shows a display device 1R which is a second modification of the display device 1P of the ninth embodiment. In the display device 1R, the surface of the first optical branch portion 4A of the display device 1N is inclined with respect to the direction along the surface of the second optical branch portion 4B. In the configuration example shown in FIG. 18, the first optical branch portion 4A is separated from the second optical branch portion 4B from the left side to the right side of the paper surface.

According to the display device 1R of the second modification of the display device 1P of the ninth embodiment, a plurality of real images and virtual images of the first light source S1 are on the surfaces of the first light branch portion 4A and the second light branch portion 4B, respectively. It is formed on a virtual circumference centered on a virtual intersection where extension lines intersect. The display device 1R is an example, but by adjusting the facing arrangement and the angle between the first optical branch portion 4A and the second optical branch portion 4B in this way, the position of the aerial image I, that is, a plurality of the first light sources S1. The position where the real image and the virtual image of the above are formed can be easily changed. The display device 1P of the ninth embodiment may be provided with an adjusting unit capable of adjusting the arrangement and angle of the first optical branching portion 4A and the second optical branching portion 4B.

Although not shown, the display device 1P and the display devices 1Q, 1P', 1R of the modified example thereof use a light source (for example, a point light source, an LED, etc.) capable of emitting a spot-shaped first light L1. Since a plurality of aerial images I can be formed, it can be applied as a kaleidoscope. Conventionally, in order to realize a kaleidoscope for multiple people, it has been necessary to increase the size of the kaleidoscope itself so that multiple people can look into it at the same time. However, by arranging the aerial image I like a pattern that can be seen by a kaleidoscope using a display device 1P or the like, a kaleidoscope pattern can be formed in the air and can be observed by a plurality of people at the same time.

(10th Embodiment)
Next, the display device 1T according to the tenth embodiment of the present invention will be described. In the components of the display device 1T of the tenth embodiment shown in FIGS. 20 to 23, the same components as those of the display device 1A of the first embodiment shown in FIGS. 1 and the like are designated by the same reference numerals. The description is omitted.
FIG. 19 shows a known display device CT.

The display device 1T of the tenth embodiment includes a backlight 55 provided with a plurality of first light sources S1, a first liquid crystal panel 51, a first polarizing plate 40A, a first light branching portion 4, and a first retroreflective portion. It is equipped with 2A.

In the display device 1T, the backlight 55 is for illuminating the first liquid crystal panel 51 and the second liquid crystal panel 52 from behind the first emission shaft J1 indicating the emission direction E1 of the first light L1. A first light source S1 is arranged on the backlight 55 with the emitting portion directed toward the first polarizing plate 40A. However, the number of liquid crystal panels stacked along the first emission axis J1 is not limited to two, and may be three or more. Further, a retardation film may be included between the liquid crystal panels laminated along the first emission axis J1.

The first liquid crystal panel 51 is arranged at a position on the first emission axis J1. The first polarizing plate 40A is arranged between the first display D1 on the first emission axis J1 and the first liquid crystal panel 51.

The first light branch portion 4 reflects at least a part of the first light L1 as the first reflected light L2, and transmits at least a part of the retroreflected light L13 retroreflected by the first retroreflecting unit 2A. The first retroreflective unit 2A is arranged at a position on the second emission axis J2 indicating the emission direction E2 of the first reflected light L2.

As shown in FIG. 19, in the conventional display device CT, in addition to the above configuration, the second liquid crystal panel 52 is arranged between the first polarizing plate 40A on the first emission axis J1 and the first liquid crystal panel 51. The second polarizing plate 40B is arranged in front of the first liquid crystal panel 51 on the first emission axis J1. The second liquid crystal panel 52 is a so-called rear liquid crystal panel. In the display device CT, the first polarizing plate 21 and the second polarizing plate 22 are arranged on the backlight 55 side with respect to the first optical branching portion 4. That is, the backlight 55, the first polarizing plate 21, the first liquid crystal panel 51, the second liquid crystal panel 52, and the second polarizing plate 22 constitute a multilayer liquid crystal display (or a laminated liquid crystal display). A half mirror can be used for the first light branching portion 4.

In the display device CT, of the first light L1 emitted from the first light source S1 of the first display D1 through the backlight 55, one of P-polarized light and S-polarized light passes through the first polarizing plate 40A, and the first liquid crystal display is used. The panel 51 and the second liquid crystal panel 52 are illuminated. The first light L1 transmitted through the second polarizing plate 40B and emitted from the first liquid crystal panel 51 is reflected as the first reflected light L2 by the first light branching portion 4. The first reflected light L2 is retroreflected as retroreflected light L13 by the first retroreflective unit 2A, passes through the first light branch portion 4, and forms an aerial image I with the first light branch portion 4 interposed therebetween.

In contrast to the display device CT described above, as shown in FIG. 20, in the display device 1T (2) of the tenth embodiment, in the configuration of the display device 1T (2) described above, the first recursion on the second emission axis J2. The first wave plate 21 is arranged behind the reflecting portion 2A. The first wave plate 21 is a so-called λ / 4 plate, and a reflective polarizing plate is used for the first light branching portion 4. The orientation of the reflective polarizing plate forming the first optical branch portion 4 is parallel to the orientation of the first polarizing plate 40A. That is, the first optical branch portion 4 and the first polarizing plate 40B are arranged so as to form a parallel Nicol (or parallel Nicol) relationship. With such an arrangement, the first light L1 emitted from the second polarizing plate 40B has a cross-nicol relationship with the first light branch portion 4, and hardly transmits the first light branch portion 4 to the first light. It is reflected as the first reflected light L2 by the one-light branch portion 4. The retroreflected light L13 reflected by the first retroreflective unit 2A after passing through the first wave plate 21 and incident on the first retroreflective unit 2A has a parallel Nicol relationship with the first light branch portion 4. Therefore, it passes through the first light branch portion 4 and forms an aerial image I.

As shown in FIG. 21, in the display device 1T (2), which is another example of the tenth embodiment, the second polarizing plate 40B is deleted in the configuration of the display device 1T (1) described above, and the first wavelength plate is removed. The optical axes of 21 are arranged so as to be parallel to the width direction of the backlight 55 including the first light source S1, that is, along a direction forming 45 degrees with respect to the polarization direction of the first polarizing plate 40A. There is. Therefore, in the display device 1T (2), the first optical branching portion 4 and the first polarizing plate 40A are arranged so as to form a parallel Nicol (or parallel Nicol) relationship with each other. The first light L1 emitted from the first liquid crystal panel 51 maintains a parallel Nicol relationship with the first light branch portion 4. The first reflected light L2 reflected by the first light branching portion 4 passes through the first wave plate 21 and is incident on the first retroreflecting portion 2A. After that, the retroreflected light L13 reflected by the first retroreflecting unit 2A becomes a parallel Nicol relationship again with respect to the first light branching unit 4, passes through the first light branching unit 4, and forms an aerial image I. do.

As shown in FIG. 22, in the display device 1T (3) which is another example of the tenth embodiment, in the configuration of the display device 1T (1) described above, the second polarizing plate 40B on the first emission axis J1 is used. The first wave plate 21 is arranged in front. Further, a second wave plate 22 is arranged behind the first retroreflective portion 2A on the second emission axis J2. In the configuration example of FIG. 22, the first wave plate 21 is arranged in the vicinity of the surface of the second polarizing plate 40B on the side of the first optical branch portion 4, and the second wavelength plate 22 is the first optical branch portion 4. It is arranged near the surface on the first retroreflective portion 2A side. Further, the orientation of the reflective polarizing plate forming the first optical branch portion 4 is orthogonal to the orientation of the first polarizing plate 40A. That is, the first optical branch portion 4 and the first polarizing plate 40A are arranged so as to form a cross Nicol (or vertical Nicol) relationship. That is, the optical axes of the first wave plate 21 and the second wavelength plate 22 are arranged so as to form 45 degrees with respect to the polarization direction of the second polarizing plate 40B.

Therefore, in the display device 1T (3), the first light L1 emitted from the first liquid crystal panel 51 passes through the second polarizing plate 40B, the first wave plate 21, and the second wavelength plate 22, respectively, and the first light branches. It has a cross Nicol relationship with Part 4. The first reflected light L2 reflected by the first light branching portion 4 passes through the second wave plate 22 and is incident on the first retroreflecting portion 2A. After that, the retroreflected light L13 reflected by the first retroreflecting unit 2A passes through the second wave plate 22 again and becomes a parallel Nicol relationship with the first light branching unit 4, and the first light branching unit 4 And forms an aerial image I.

As shown in FIG. 23, in the display device 1T (4) which is another example of the tenth embodiment, the second polarizing plate 40B is deleted in the configuration of the display device 1T (3) described above, and the first emission shaft is removed. The first wave plate 21 is arranged in front of the first liquid crystal panel 51 on J1. Further, the orientation of the reflective polarizing plate forming the first optical branching portion 4 is orthogonal to the orientation of the first polarizing plate 40A, and the first optical branching portion 4 and the first polarizing plate 40A are cross-nicols (or vertical). It is arranged so as to form a relationship of Nicole). On the other hand, the first wave plate 21 and the second wave plate 22 are arranged so that the optical axes of the first wave plate 21 and the second wave plate 22 form 45 degrees with respect to the optical axis of the first liquid crystal panel 51. There is.

Therefore, in the display device 1T (4), the first light L1 emitted from the first liquid crystal panel 51 passes through the first wave plate 21 and the second wave plate 22, respectively, and is parallel to the first light branch portion 4. Make a relationship with Nicole. The first reflected light L2 reflected by the first light branching portion 4 passes through the second wave plate 22 and is incident on the first retroreflecting portion 2A. After that, the retroreflected light L13 reflected by the first retroreflecting unit 2A passes through the second wave plate 22 again and becomes a parallel Nicol relationship with the first light branching unit 4, and the first light branching unit 4 And forms an aerial image I.

According to the display device 1T of the tenth embodiment described above, the user is in the space A (that is, the space where the user is with respect to the first optical branch portion 4) as in the display device 1A of the first embodiment. The aerial image I can be observed. Further, in a normal liquid crystal display, a polarizing plate is also arranged on the user side, and a part of light is absorbed by this polarizing plate. In particular, according to the display devices 1T (2) and 1T (4) of the tenth embodiment, the configuration in which the polarizing plate (that is, the second polarizing plate 40B) arranged on the user side in a normal liquid crystal display is deleted is provided. It can be realized. As a result, the attenuation of light due to absorption by the polarizing plate is eliminated, and the brightness of the aerial image I is improved, so that the user can easily see the aerial image I, and a secure aerial display or multi-layer display that is easy on the user's eyes. Can be realized.

Further, in the method of displaying an aerial image to which the present invention is applied, the first light L1 is emitted from the first light source S, and the first light L1 is transmitted from the first retroreflective unit 2 at a position on the first emission axis J1. A step, a step of reflecting at least a part of the first light L1 transmitted through the first retroreflective unit 2 toward the first retroreflective unit 2 as the first reflected light L2 by the first light branching unit 4, and a first step. A step of transmitting at least a part of the first reflected light L2 retroreflected by the retroreflecting unit 2 from the first light branching unit 4 is provided.
According to the above-mentioned aerial image display method, the aerial image I can be observed from a wider angle.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific embodiment, and various aspects are described within the scope of the claims of the present invention. It can be transformed and changed.

For example, the configuration of the display device 1B shown in FIG. 4 may be changed as shown in FIG. 24. That is, the first polarization branching portion 25 of the display device 1B may be omitted, and the fifth display D5 may be adopted instead of the first display D1. For the first light branching portion 4, for example, a reflective polarizing film or the like can be used.

The plane of the fifth display D5 is divided into an S wave light emitting unit SS1 that emits the first light L1 of S wave polarization and a P wave light emitting unit SP1 that emits the first light L1 of P wave polarization. As the S wave light emitting unit SS1, for example, a combination of an LED light source and a polarizing plate capable of emitting S-polarized light can be used, but the S wave light emitting unit SS1 is not particularly limited. Further, the P-wave light emitting unit SP1 can be used, for example, a combination of an LED light source and a polarizing plate capable of emitting P-polarized light, but is not particularly limited. Further, in the fifth display D5, the polarization (S wave or P wave) emitted for each predetermined region in the plane of the fifth display D5 can be adjusted by a control unit (not shown).

According to the display device 1M described above, the polarization of the first light L1 is adjusted by S wave or P wave for each predetermined region in the plane of the fifth display D5, and as shown in FIG. 24, the user is S-wave polarized. Along with the aerial image I by P-wave polarization or the aerial image I by P-wave polarization, a direct image by P-wave polarization or S-wave polarization can be seen on the fifth display D5. Since the aerial image and the direct image are separated for each pixel, it is possible to independently display a two-layer image while using a single display D5. Therefore, the display device 1M can be applied to a DFD (Deepth-fused 3D) display in which the depth is perceived at a position corresponding to the brightness ratio of each of the S wave light emitting unit SS1 and the P wave light emitting unit SP1.

Further, as a modification of the display device 1M, the display device 1N shown in FIG. 25 can be mentioned. The display device 1N omits the first wave plate 21 and the second wave plate 22 in the configuration of the display device 1M, and instead has the fifth display D5 (first light source S1) and the fifth display D5 (first light source S1) on the first emission axis J1. A 3D film 44 is arranged between the retroreflective unit 2A and the retroreflective unit 2A. Examples of the 3D film 44 include a parallax barrier, a parallax barrier, a lenticular lens, and the like.

According to the display device 1N described above, the polarization of the first light L1 is adjusted by S wave or P wave for each predetermined region in the plane of the fifth display D5, and as shown in FIG. 25, the user S with the right eye. The aerial image I of one of the wave polarization and the P wave polarization can be seen, and the aerial image I of the other of the S wave polarization and the P wave polarization can be seen with the left eye. Therefore, the display device 1N can be applied to the DFD display in which the depth is perceived at the position corresponding to the brightness ratio of each of the S wave light emitting unit SS1 and the P wave light emitting unit SP1.

Further, in the display device according to the present invention, an image forming element may be arranged between the first light source S1 on the first emission axis J1 and the first retroreflective unit 2. Examples of the image forming element include a lenticular lens and a fly eye lens. A three-dimensional display may be used as the display provided with the first light source S1 and the second light source S2.

Further, the display device according to the present invention may be housed in a housing or the like. FIG. 26 illustrates a configuration in which a part of the configuration of the display device 1B according to the present invention is housed in the housing 30. Specifically, the first light source S1, the first display D1, the first retroreflective unit 2 and the first wave plate 21 of the display device 1B are housed inside the housing 30. The first wave plate 21 is provided in contact with the upper surface side of the first retroreflective portion 2. A reflective polarizing plate (or a reflective polarizing sheet or the like) is provided on the upper surface of the housing 30 as the first light branching portion 4.
One of the P-polarized or S-polarized light of the first light L1 emitted from the first light source S1 is reflected by the first light branching portion 4, passes through the first wave plate 21, and is retroreflected by the first retroreflecting portion 2. It is reflected and passes through the first wave plate 21 again. At this time, the polarization of the first light L1 changes, and as the other of the P polarization and the S polarization, the light is incident on and transmitted to the first light branch portion 4 to form an aerial image I. Therefore, the user can observe the aerial image I from a certain direction E0. Such a display device is portable, can flexibly respond to a place and installation conditions, and can show the aerial image I to the user.

Further, in the display device according to the present invention, the prism sheet may be arranged in front of the first light source S1 on the first emission axis J1 or the display provided with the above-mentioned light source. Here, the prism sheet (not shown) is a structure in which a plurality of prism structures having a triangular cross section are arranged in a predetermined direction of a base portion (base material). Examples of the prism structure include a right-angled triangle with a right-angled portion in contact with the base material side, a right-angled triangle with a long side in contact with the base material, and an isosceles triangle. It is not particularly limited as long as it can be obtained. Such a prism sheet can be provided on the first light source S1, the second light source S2, a display, or the like so that a plurality of prisms are arranged in a direction orthogonal to the first emission axis J1.

By arranging the prism sheet in front of the first light source S1 on the first emission axis J1 or the display provided with the above-mentioned light source, the first light L1 is refracted in a predetermined direction on the surface of the prism. Therefore, by appropriately setting the angle of the surface of the prism structure protruding from the base material, light is collected at the formation position of the aerial image I and the brightness of the aerial image I is improved as compared with the case where the prism sheet is not provided. be able to. Further, it is considered that the edge portion of the aerial image I is blurred due to the influence of light scattering and diffraction. However, by using the prism sheet, the edge of the aerial image I can be sharpened.

Further, in front of the first light source S1 on the first emission axis J1 and the display provided with the above-mentioned light source, a plurality of those having the same type and pitch of the prism structure or those having different pitches may be laminated. good. This makes it possible to finely set the refraction direction of the first light L1.

Further, the display device according to the present invention may have a configuration in which the housing 30 is omitted from the display device shown in FIG. 26, as illustrated in FIG. 27, and a finger (just a finger) is placed at the aerial image I. If there is f) in FIG. 24, it can be utilized as a contact determination device based on the fact that a large amount of scattered light is detected. In the past, when trying to detect scattered light, the camera CC was placed at the position shown by the broken line in FIG. 24 for shooting, but by arranging the camera CC at the position shown by the solid line in the figure, the camera CC is placed in the air. The contact of any object with the image I can be sensitively detected and determined.

Next, an example carried out to support the effect of the display device of each embodiment according to the present invention will be described. The present invention is not limited to the following examples.

(Example 1)
In order to configure the display device 1A shown in FIG. 1, an LED that emits visible light was used as the first light source S1. Further, a special display in which a plurality of first light sources S1 are arranged on the surface of the first display D1 is prepared. For the first retroreflective unit 2, a retroreflective sheet (product name: high-gloss reflective trim 6160R, manufacturer: 3M) having a unit structure 10 having a size of about 180 μm and made of transparent plastic was used. A half mirror was used for the first light branching portion 4.
In the constructed display device 1A, when the character "A" is displayed on the first display D1, for example, it is confirmed that the first light source S1 and the aerial image I of the character "A" are observed as shown in FIG. 28. bottom.

(Example 2)
In order to configure the display device 1E shown in FIG. 7, two first displays D1 similar to those in the first embodiment were used. For the second retroreflective unit 6, the same retroreflective sheet as the first retroreflective unit 2 was used.
When the first display D1 displays, for example, the character "A" and the first display D1 displays, for example, the character "B" in the constructed display device 1E, as shown in FIG. 29, it is viewed from the observation direction E0. In this case, the aerial image I of the letter "A" and the "B" by the second light source S2 of the second display D2 can be seen, and when viewed from the observation direction E10, the aerial image I of the letter "B" and the first It was confirmed that "B" by the first light source S1 of one display D1 was observed.

(Example 3)
In order to configure the display device 1G shown in FIG. 9, an LED that emits visible light was used as the first light source S1 as in the first embodiment. For the first retroreflective unit 2C, a corner cube type retroreflective sheet having a retroreflective structure 3A (product name: retroreflective sheet QR-1 with retardation film, manufacturer: NS Partners Co., Ltd.) was used. For the first light branching portion 4, a reflective polarizing film (product name: SHM-2, manufacturer: SN Partners) attached to a transparent acrylic plate was used.
In the constructed display device 1G, when the character "T" is displayed on the fourth display D4, for example, it is confirmed that the first light source S1 and the aerial image I of the character "T" are observed as shown in FIG. bottom.

Further, instead of the retroreflective sheet having the retroreflective structure 3A, a bead type retroreflective sheet having the retroreflective structure 3B (product name: ultra-high brightness reflective sheet 7610, manufacturer: 3M Co., Ltd.) is used for the display device 1G. ´ was constructed.
In the constructed display device 1G', when the character "A" is displayed on the fourth display D4, for example, as shown in FIG. 31, the first light source S1 and the aerial image I of the character "A" are observed. confirmed.

(Example 4)
In the display device 1G of the third embodiment, the first optical branching portion 4 is tilted at a distance of approximately 45 ° with respect to the surface of the fourth display D4 (that is, the first light source S1 and the first retroreflective portion 2C). By arranging them, the display device 1H shown in FIG. 11 was configured.
In the constructed display device 1H, when the character "T" is displayed on the fourth display D4, for example, it is confirmed that the first light source S1 and the aerial image I of the character "T" are observed as shown in FIG. bottom.

(Example 5)
In the display device 1H of the fourth embodiment, the first retroreflective unit 2C is moved to the position P2 in the emission direction E1 of the first light L1 with the first light source S1 on the first emission axis J1 as a reference, and the first emission axis J1. By arranging the polarizing plate 40 between the first light source S1 and the first retroreflective unit 2C, the display device 1H shown in FIG. 11 was configured. A polarizing film (product name: polarizing film HN42, manufacturer: Polaroid) was used as the polarizing plate 40.
When the letter "T" is displayed on the fourth display D4 in the constructed display device 1H, for example, as shown in FIG. 33, the first light source S1 of the letter "T" is displayed by the first optical branch portion 4 and the polarizing plate 40. It was confirmed that only the aerial image I of the letter "T" was observed because (that is, the directly transmitted light) was blocked.

(Example 6)
In order to configure the display device 1P shown in FIG. 15, an LED that emits visible light was used as the first light source S1 as in the first embodiment. An LED tape was used in which three LEDs were arranged at intervals in the width direction and a plurality of LEDs were arranged at a predetermined interval in the length direction. A corner cube type retroreflective sheet (product name: Nikkalite crystal grade, manufacturer: Nippon Carbide Industries Co., Ltd.) having a retroreflective structure 3A was used for the first retroreflective unit 2C. For the first light branching portion 4, a reflective polarizing film (product name: SHM-2, manufacturer: SN Partners Co., Ltd.) attached to a transparent acrylic plate was used.
As shown in FIG. 34, in the constructed display device 1P, it was confirmed that an aerial image I and a virtual image composed of a plurality of spot lights corresponding to the LEDs arranged on the LED tape were observed.

Further, as shown in FIG. 16, in order to configure the display device 1Q provided with the first light source S1 and the second light source S2, an LED tape in which LEDs are arranged on both sides was used. Such a double-sided LED tape corresponds to one in which the first light source S1 and the second light source S2 shown in FIG. 16 are arranged apart from each other by the thickness dimension of the tape base material. By arranging the light sources on both sides of the tape in this way, it was confirmed that the aerial image I and the virtual image were observed from both sides of the LED tape as shown in FIG. 35.

(Comparative Example 1, Example 7)
In order to configure the display device 1T shown in FIGS. 20 to 23, special color displays (first liquid crystal display 51 and second display 52) including a plurality of LEDs that emit visible light are prepared as the first light source S1. Specifically, as the backlight 55, the first liquid crystal display 51 and the second display 52, a high-definition high-brightness LED panel (pitch 4 mm, surface mount package type, product name: P4-LED panel, distributor: WAN Color). , And a polysilicon TFT liquid crystal panel (product name: LTM10C348S, manufacturer: Toshiba Co., Ltd.) disassembled. For the first retroreflective unit 2A, a retroreflective sheet (product name: Nikkalite crystal grade, manufacturer: Nippon Carbide Industry Co., Ltd.) having a unit structure 10 having a size of about 180 μm and made of transparent plastic was used. .. A commercially available half mirror (both reflectance and transmittance of about 50%) or a reflective polarizing film (product name: SHM-2, manufacturer: NS Partners Co., Ltd.) is attached to the first light branch portion 4 on a transparent acrylic plate. I used the one I put on. For the first polarizing plate 40A and the second polarizing plate 40B, a polarizing plate taken out by disassembling the above-mentioned polyvinyl TFT liquid crystal panel or a polarizing plate commercially available as a single substance (product name: HN42, manufacturer: Polaroid) is used. used. Commercially available λ / 4 plates were used for the first wavelength plate 21 and the second wavelength plate 22.

The display device CT shown in FIG. 19 and the display device 1T shown in FIGS. 20 to 23 were respectively constructed by using each of the above-mentioned components, and formed from the color image shown in FIG. 36 displayed on the special color display. Each aerial image I is attached to an image camera (product name: D5500, manufacturer: Nikon Corporation) and a lens (product name: FS DX NIKKOR 18-140mm f / 3.5-5.6G ED VR, manufacturer: Nikon Corporation). An image was taken using a lens equipped with Nikon). The F value of the image pickup camera was set to 4.8, and the shutter speed at the time of image pickup was set to 1/10 (ISO: 400).
Note that FIGS. 36 and 41 are both shown as grayscale images.

In the display device CT constructed as a comparative example, an aerial image I corresponding to the image of the special color display was imaged by using a half mirror as the first light branching portion 4. As shown in FIG. 37.

In the display device 1T (1) constructed as an embodiment, a reflective polarizing plate is used as the first optical branching portion 4 instead of a half mirror, and the arrangement is as described above, as shown in FIG. 38. An aerial image I brighter than the aerial image I shown in FIG. 37 was imaged.

Further, in the constructed display device 1T (2), a reflective polarizing film (product name: SHM-2, manufacturer: SN Partners Co., Ltd.) attached to a transparent acrylic plate is used as the first polarizing plate 40A). Moreover, by not using the second polarizing plate 40B, the loss of the first light L1 was suppressed, and as shown in FIG. 39, a clearer aerial image I than in FIG. 38 was imaged.

Further, in the constructed display device 1T (3), as shown in FIG. 40, an aerial image I having the same brightness as that of the display device 1T (1) shown in FIG. 38 was imaged.
Further, in the constructed display device 1T (4), the above-mentioned reflective polarizing film is used as the first polarizing plate 40A, and the first wavelength plate 21 and the second wavelength plate 22 are used without using the second polarizing plate 40B. By using this, as shown in FIG. 41, an aerial image I which is brighter than the aerial image I of the display device 1T (3) shown in FIG. 40 but has a slightly lower contrast was imaged.

(Example 8)
In the display device 1T (2) constructed in the seventh embodiment, the image of the character "F" composed of a single color is displayed on the first liquid crystal panel 51, and the "B" composed of a single color is displayed on the second liquid crystal panel 52. The aerial image I when the image of the character of was displayed was taken. The F value of the imaging camera was changed to 3.5, and the shutter speed at the time of imaging was left at 1/10 (ISO: 400).

As a result of photographing from the left direction, the front direction, and the right direction with respect to the direction facing the aerial image I, it was confirmed that each aerial image I shown in FIGS. 42, 43, and 44 was formed. It was confirmed that the aerial image I taken from the front direction is the brightest and clearest, but the aerial image I in which the letters "F" and "B" can be clearly read can be obtained even when taken from the left and right directions. bottom. Parallax corresponding to the distance between the two layers was observed from the left and right, and it was confirmed that a deep aerial image I was formed.

In the above configuration, instead of the letters "F" and "B", a band-shaped monochromatic dot pattern (drawing) in which the density continuously changes in the left-right direction with respect to the direction facing the aerial image I is displayed. The formed aerial image I was photographed. It was confirmed that the aerial images I shown in FIGS. 45, 46, and 47 were formed. In addition, the monochromatic dot pattern was observed to have a depth in the diagonal direction.

(Example 9)
In the display device 1T (4) constructed in the seventh embodiment, as shown in FIG. 48, the wave plate 53 can be arranged between the first liquid crystal panel 51 and the second liquid crystal panel 52 on the first emission shaft J1. Therefore, a color tone correction test was performed. The wave plate 53 is a so-called λ / 2 plate, and gives a phase difference of π in the electric field vibration direction of the incident light.

FIG. 49 shows a photograph of the aerial image I in the display device 1T (4) before the wave plate 53 is arranged. On the other hand, in FIG. 50, the wave plate 53 is arranged between the first liquid crystal panel 51 and the second liquid crystal panel 52 on the first emission axis J1, and the optical axis of the wave plate 53 is in the width direction of the backlight 55. The photograph of the aerial image I when the wave plate 53 is arranged so as to form 45 degrees with respect to the above is shown. As can be seen from FIG. 50, when the wave plate 53 is arranged, the coloring phenomenon due to the wavelength dispersion is eliminated, and the color of the portion where the red aerial image I was formed before the arrangement of the wave plate 53 is changed. It's gone. That is, although both FIG. 49 and FIG. 50 are shown as grayscale images, the “colored portion” shown in FIG. 50 is darker than the “colored portion” shown in FIG. 49. , It is possible to confirm the elimination of the above-mentioned coloring phenomenon.

As can be seen from the examples described above, according to the display device to which the present invention is applied, the aerial image I can be observed from a wider angle, and it can be seen that the action and effect in various configurations can be obtained.

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H, 1K, 1M, 1N, 1P, 1P', 1Q, 1R, 1T (1), 1T (2), 1T (3), 1T (4) , 1V, 1W ... Display device 2 ... First retroreflective part 4 ... First light branching part 5 ... Second light branching part 6, 7 ... Second retroreflective part 21 ... First wavelength plate 22 ... Second wavelength plate 23 ... Third wavelength plate 24 ... Fourth wavelength plate 50A ... First reflector 50B ... Second reflector E1, E2 ... Emission direction L1 ... First light L2 ... First reflected light L21 ... Second light S1 ... First light source S2 ... Second light source

Claims (4)

A display that includes an S wave emitting unit that emits S wave polarization and a P wave emitting unit that emits P wave polarization, and emits light including the S wave polarization and the P wave polarization.
A first wave plate that transmits the light by giving a phase difference of (π / 2) in the electric field vibration direction of the incident light, and
A first retroreflective unit that transmits light incident from the display side and retroreflects light incident from the side opposite to the display side.
A second wave plate that transmits the light by giving a phase difference of (π / 2) in the electric field vibration direction of the incident light,
An optical branching portion that splits the light incident from the display side into reflected light and transmitted light,
Equipped with
The display, the first wave plate, the first retroreflective part, the second wave plate, and the optical branching part are arranged in this order.
The light emitted from the display passes through the first wave plate, the first retroreflective portion, and the second wavelength plate, and enters the optical branch portion.
The light reflected by the optical branching portion passes through the second wave plate and is retroreflected by the first retroreflective portion.
Display device. A display that includes an S wave emitting unit that emits S wave polarization and a P wave emitting unit that emits P wave polarization, and emits light including the S wave polarization and the P wave polarization.
A three-dimensional film comprising at least one of a transmissive parallax barrier, a transmissive parallax barrier, and a transmissive lenticular lens.
A first retroreflective unit that transmits light incident from the display side and retroreflects light incident from the side opposite to the display side.
An optical branching portion that splits the light incident from the display side into reflected light and transmitted light,
Equipped with
The display, the three-dimensional film, the first retroreflective part, and the optical branching part are arranged in this order.
The light emitted from the display passes through the three-dimensional film and the first retroreflective portion and is incident on the optical branch portion.
The light reflected by the optical branching portion is retroreflected by the first retroreflective portion.
Display device. The three-dimensional film emits the S-wave polarization emitted from the display toward the first observation position, and the P-wave polarization emitted from the display is a second observation position different from the first observation position. Emit toward
The display device according to claim 2. The S-wave polarization or the P-wave polarization emitted from the region is adjustable for each predetermined region in the plane of the display.
The display device according to any one of claims 1 to 3.

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