JP2017107165A - Display device and display method of aerial image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a display device which allows observation of an image formed in the air at a wider angle.SOLUTION: A display device 1A which is an embodiment applied with the present invention includes a first light source S1, a first retroreflection part 2 arranged at a position in an emission direction E1 of a first light L1 emitted from the first light source S1, and a first optical branch part 4 which reflects at least a part of the first light L1 transmitting the first retroreflection part 2 as a first reflection light L2 and allows at least a part of the first reflection light L2 which is retro-reflected by the first retroreflection part 2 to pass through.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a display device and an aerial image display method.

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

  A display device 101 illustrated in FIG. 51 is an example of an AIRR configuration, and includes a light source S, a half mirror 104, and a retroreflecting unit 106 provided in the display D1 and the like. Among the light L1 emitted from the light source S, a part of the light L101 is reflected as reflected light L102 by the half mirror 104. The reflected light L102 enters the retroreflecting unit 106, is reflected in the same direction as the incident direction by the retroreflecting unit 106, enters the half mirror 104 as reflected light L103, passes through the half mirror 104, and enters the half mirror 104. On the other hand, an aerial image I is formed at a position Q1 that is plane-symmetric with respect to the display D1. The user can see the aerial image I displayed in the space A (that is, the space where the user is with respect to the half mirror 104) from the observation direction E0 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 a range in which the retroreflective unit 106 can be seen through the half mirror 104 from the viewpoint position of the user. Even if the aerial image I is formed, the user can only observe the aerial image in a certain area Z1.

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

JP-T 9-506717

H. Yamamoto, Y. et al. Tomiyama, S .; Suyama, “Floating aerial LED signing 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 out of the light L1 is reflected by the half mirror 104 and then enters the display D as reflected light L106 and L109. Does not contribute to formation. That is, the conventional display device based on AIRR has a problem that the angle θ101 at which the aerial image I can be seen becomes small because the light L1 includes the light 105 that does not form the aerial image I.

  The present invention has been made to solve the above problems, and provides a display device and an aerial image display method that allow an image formed in the air (aerial image) to be observed from a wider angle.

  The display device according to the present invention includes a first light source, a first retroreflecting portion disposed at a position on a first emission axis indicating an emission direction of the first light emitted from the first light source, and the first A first light branching unit that reflects at least a part of the first light emitted from the light source as a first reflected light and transmits at least a part of the first reflected light retroreflected by the first retroreflective unit. And.

In the display device according to the present invention, the first retroreflective portion is arranged in the emission direction of the first light with respect to the first light source on the first emission axis, and is capable of transmitting the first light. May be.
In the display device according to the present invention, the first retroreflective portion is disposed on the opposite side of the first light emission direction with respect to the first light source on the first emission axis, and the first emission In the position where the first light source is disposed on the axis, the non-arranged portion of the first light source may be capable of transmitting the first light and the first reflected light.
In the display device according to the present invention, the first retroreflective portion may be disposed at a position where the first light source is disposed on the first emission axis.

In the display device according to the present invention, the first reflected light may be incident on the first retroreflective portion.
In the display device according to the present invention, the first reflected light is incident on the first retroreflective portion and is disposed between the first light source on the first emission axis and the first retroreflective portion. A first wave plate, a second wave plate disposed in the light emitting direction of the first light with reference to the first retroreflecting portion on the first light emitting axis, and the first wave plate on the first light emitting axis. A first polarization branching unit that is disposed between the light source and the first wavelength plate and is capable of transmitting specific polarized light, wherein the first wavelength plate and the second wavelength plate A phase difference of (π / 2) may be given in the electric field oscillation direction.

  The display device according to the present invention may further include a second retroreflective portion disposed at a position on the second emission axis indicating the emission direction of the first reflected light reflected by the first light branching portion. Good.

  In the display device according to the present invention, the first wave plate disposed between the first light source on the first emission axis and the first retroreflective portion, and the first wave on the first emission axis. A second wave plate arranged in the emission direction of the first light with reference to one retroreflecting part, and arranged between the first light source and the first wave plate on the first emission axis; A first polarization branching portion capable of transmitting polarized light, a second light source that emits second light to the opposite side of the emission direction of the first reflected light reflected by the first light branching portion, and the second light The second retroreflective portion that is disposed at a position on the third output axis indicating the emission direction, can retroreflect the first reflected light and transmit the second light, and the second retroreflective portion is transmitted. At least a part of the second light is reflected as second reflected light, and the second reflection is retroreflected by the second retroreflective portion. A second light branch that transmits at least part of the light; a third wave plate disposed between the second light source on the third emission axis and the second retroreflecting part; and the third emission. A fourth wave plate arranged in the direction of emission of the second light with respect to the second retroreflective portion on the axis, and between the second light source and the third wave plate on the third emission axis. A second polarization branching portion that is arranged and capable of transmitting polarized light orthogonal to the specific polarized light, and the first wave plate, the second wave plate, the third wave plate, and the fourth wave plate are: A phase difference of (π / 2) may be given in the electric field oscillation direction of light incident on each.

  In the display device according to the present invention, the second light source that emits the second light to the opposite side of the emission direction of the first reflected light reflected by the first light branching portion, and the emission direction of the second light And a second retroreflective portion that is capable of retroreflecting the first reflected light and transmitting the second light.

  In the display device according to the present invention, an imaging element may be disposed between the first light source on the first emission axis and the first retroreflective portion.

  In the aerial image display method according to the present invention, the first light is emitted from the first light source, and the first light is emitted from the first retroreflective portion at a position on the first emission axis indicating the emission direction of the first light. Transmitting, reflecting at least a part of the first light transmitted through the first retroreflecting portion toward the first retroreflecting portion as first reflected light by the first light branching portion, and the first Transmitting at least a part of the first reflected light retroreflected by one retroreflecting section from the first light branching section.

  The display device according to the present invention includes a first light source, a first light branching unit that reflects at least a part of the first light emitted from the first light source as first reflected light, and the first light. A first retroreflective portion disposed at a position on the second reflection axis indicating the emission direction of the first reflected light reflected by the branching portion, and the first light branching portion from the outer periphery to the center As it goes, the first light branching portion is curved in a convex shape on the side opposite to the side where the first light source and the first retroreflective portion are arranged.

  The display device according to the present invention extends from the first light source and one side of the first light source along a first emission axis indicating an emission direction of the first light emitted from the first light source. The first wave plate, the first retroreflecting portion provided on the opposite side of the first wave plate from the side facing the first light source, and the other side of the first light source, A first reflecting plate extending along the emission axis, a first light branching portion provided between a tip of the first wave plate and a tip of the first reflecting plate, and the first reflecting plate And a second reflecting plate extending in the same direction as the extending direction of the first reflecting plate with the first light branching portion interposed therebetween, and the first wavelength plate is incident on each of the second reflecting plates A phase difference of (π / 2) is given in the electric field oscillation direction of light.

  The display device according to the present invention includes a first light source, a first light branching portion disposed so as to face each other across the first light source, and a second light branching portion. An emission part of the light source is directed to a space formed between the first light branching part and the second light branching part, and the first light branching part and the second light branching part are from the first light source. Reflecting at least part of the emitted first light as first reflected light and reflecting at least part of the first reflected light, one of the first light branching part and the second light branching part A first retroreflective portion is provided on the opposite side of the optical branching portion to the side facing the other optical branching portion.

  The display device according to the present invention includes a first light source, a first liquid crystal panel disposed at a position on a first emission axis indicating an emission direction of the first light emitted from the first light source, and the first liquid crystal panel. A first polarizing plate disposed between the first light source on the one emission axis and the first liquid crystal panel, and at least a part of the first light emitted from the first light source as first reflected light A first light branching portion that reflects and transmits at least a portion of the first reflected light that is retroreflected by the first retroreflecting portion, and a position on the second emission axis that indicates an emission direction of the first reflected light And a first retroreflective portion disposed on the surface.

  In the display device according to the present invention, a second liquid crystal panel is disposed between the first polarizing plate on the first output axis and the first liquid crystal panel, and the first liquid crystal on the first output axis is A second polarizing plate is disposed in front of the liquid crystal panel, a first wave plate is disposed behind the first retroreflective portion on the second emission axis, and the first wave plate is an electric field vibration of incident light. A phase difference of (π / 2) is given to the direction, the first light branching portion is a reflective polarizing plate, and the polarization direction of the reflective polarizing plate is parallel to the polarization direction of the first polarizing plate. It may be.

  In the display device according to the present invention, a second liquid crystal panel is disposed between the first polarizing plate on the first output axis and the first liquid crystal panel, and the first liquid crystal on the second output axis is provided. A first wave plate is disposed behind the retroreflecting unit, the first wave plate gives a phase difference of (π / 2) in the electric field vibration direction of incident light, and the first light branching unit is a reflection type The polarizing direction of the reflective polarizing plate is parallel to the polarizing direction of the first polarizing plate, and the optical axis of the first wave plate is in the width direction of the first light source. You may arrange | position in parallel with respect to.

  In the display device according to the present invention, a second liquid crystal panel is disposed between the first polarizing plate on the first output axis and the first liquid crystal panel, and the first liquid crystal on the first output axis is A second polarizing plate and a first wave plate are disposed in front of the liquid crystal panel, a second wave plate is disposed behind the first retroreflective portion on the second output axis, and the polarization of the reflective polarizing plate The direction is orthogonal to the direction of polarization of the first polarizing plate 4, and the optical axes of the first wave plate and the second wave plate are respectively disposed perpendicular to the width direction of the first light source. Also good.

  In the display device according to the present invention, a second liquid crystal panel is disposed between the first polarizing plate on the first output axis and the first liquid crystal panel, and the first liquid crystal on the first output axis is A first wave plate is disposed in front of the liquid crystal panel, a second wave plate is disposed behind the first retroreflective portion on the second emission axis, and the polarization direction of the reflective polarizing plate is determined by the first polarization plate. The optical axis of the first wave plate and the second wave plate may be arranged in parallel to the width direction of the first light source.

  Furthermore, in the display device according to the present invention, a prism sheet having a plurality of prisms in a direction orthogonal to the first emission axis may be disposed in front of the first light source on the first emission axis.

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

It is the schematic which shows the structure of the display apparatus 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 for the display apparatus 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 for the display apparatus of 1st embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 2nd embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 3rd embodiment which concerns on this invention. It is the schematic which shows the structure of the modification of the display apparatus of 3rd embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 4th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 5th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 6th embodiment which concerns on this invention. It is a top view of the 4th display of the display apparatus shown in FIG. It is the schematic which shows the structure of the display apparatus which is the 1st modification of 6th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus which is the 2nd modification of 6th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 7th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 8th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 9th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus which is the 1st modification of 9th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus which is another modification of 9th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus which is the 2nd modification of 9th embodiment which concerns on this invention. It is the schematic which shows the structure of the display apparatus of 10th Embodiment which concerns on this invention. It is the schematic which shows another structure of the display apparatus of 10th Embodiment which concerns on this invention. It is the schematic which shows another structure of the display apparatus of 10th Embodiment which concerns on this invention. It is the schematic which shows the other structure of the display apparatus of 10th Embodiment which concerns on this invention. It is the schematic which shows other structure of the display apparatus of 10th Embodiment which concerns on this invention. It is the schematic which shows the structure of the 1st modification of the display apparatus which concerns on this invention. It is the schematic which shows the structure of the 2nd modification of the display apparatus which concerns on this invention. 1 is a schematic view showing a configuration of a display device according to the present invention and housed in a housing. It is the schematic which shows the usage example of the display apparatus which concerns on this invention. It is the photograph of the directly transmitted light by the aerial image and light source which were displayed by the display apparatus 1A of Example 1. FIG. It is the photograph of the direct transmitted light by the aerial image and light source which were displayed by the display apparatus 1E of Example 2. FIG. It is the photograph of the directly transmitted light by the aerial image and light source which were displayed by the display apparatus 1G of Example 3. FIG. It is the photograph of the direct transmitted light by the aerial image and light source which were displayed by display apparatus 1G 'of Example 3. FIG. It is the photograph of the direct transmitted light by the aerial image and light source which were displayed by the display apparatus 1H of Example 4. FIG. It is the photograph of the directly transmitted light by the aerial image and light source which were displayed by the display apparatus 1K of Example 5. FIG. 10 is a photograph of an aerial image displayed by a display device 1P of Example 6. 10 is a photograph of an aerial image displayed by a display device 1Q of Example 6. It is an emitted image of the special color display used in Example 7 and Comparative Example 1. 10 is a photograph of an aerial image displayed by the display device CT of Comparative Example 1. It is the photograph of the aerial image displayed by display apparatus 1T (1) of Example 7. FIG. It is the photograph of the aerial image displayed by display apparatus 1T (2) of Example 7. FIG. It is the photograph of the aerial image displayed by display apparatus 1T (3) of Example 7. FIG. It is the photograph of the aerial image displayed by display apparatus 1T (4) of Example 7. FIG. It is the photograph which image | photographed the aerial image displayed by display apparatus 1T (2) of Example 8 on the left side of the direction which opposes an aerial image. It is the photograph which image | photographed the aerial image displayed by display apparatus 1T (2) of Example 8 in the front of the direction which opposes an aerial image. It is the photograph which image | photographed the aerial image displayed by display apparatus 1T (2) of Example 8 on the right side of the direction which opposes an aerial image. It is the photograph which image | photographed on the left of the direction which opposes another aerial image displayed with display apparatus 1T (2) of Example 8 with respect to an aerial image. It is the photograph which image | photographed the other aerial image displayed by display apparatus 1T (2) of Example 8 in the front of the direction which opposes an aerial image. It is the photograph which image | photographed the other aerial image displayed by display apparatus 1T (2) of Example 8 on the right side of the direction which opposes an aerial image. 10 is a schematic diagram illustrating a configuration of a display device according to Example 9. FIG. It is the photograph of the aerial image displayed before arrange | positioning the wavelength plate 53 in the display apparatus of Example 9. FIG. It is the photograph of the aerial image displayed when the wavelength plate 53 was arrange | positioned in the display apparatus of Example 9. FIG. It is the schematic which shows the structure of the conventional display apparatus.

  Hereinafter, embodiments of a display device and an aerial image display method 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, and the like are not necessarily the same as actual ones, and can be changed as appropriate.

(First embodiment)
As shown in FIG. 1, the display device 1 </ b> A of the first embodiment includes a first light source S <b> 1, a first retroreflective unit 2 </ b> A, a first light branching unit 4, and a second retroreflective unit 6. Yes.

  Although 1st light source S1 is LED, for example, it is not specifically limited. A plurality of first light sources S1 of the display device 1A of the first embodiment are arranged in parallel to the plate surface of the first display D1, and are provided with the light emission directions 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 portion 2 is disposed at a 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 portion 2A of the first embodiment is arranged in the emission direction E1 with the first light source S1 on the first emission axis J1 as a reference. The first retroreflective portion 2A is preferably disposed in the vicinity of the first display D1 (that is, the position PS1 of the first light source S1) on the first emission axis J1. The first retroreflective portion 2A may be attached to the emission direction E1 side of the first light source S1 of the first display D1, and may be integrated with the first display D1.

  The first retroreflective portion 2A has a known retroreflective structure. Examples of the retroreflective structure of the first retroreflective portion 2A include retroreflective structures 3A and 3B including a plurality of unit structures 10 each having at least one reflective surface 12 as shown in FIGS. .

The surface 3a (that is, the surface on which light is incident) of the retroreflective structure 3A shown in FIG. 2 is formed flat. On the other hand, a plurality of triangular shapes constituting the unit structure 10 are formed on the surface 3b of the retroreflective structure 3A 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 is transmitted through the surface 2a and is incident on the reflecting surface 12a of the unit structure 10 as light L10b. The light L10b is reflected by the reflection surface 12a and travels toward the reflection surface 12c of the unit structure 10 as light L10c. In the retroreflective structure 3A, the inner angle formed by the reflection surfaces 12a and 12c of the unit structure 10 is set to a predetermined angle (that is, approximately 90 °). Accordingly, the light L10c incident on the reflecting surface 12c is reflected as light L10d in the direction parallel to the light L10b by the reflecting surface 12c, and is emitted from the surface 3a as 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 not shown.

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 are formed adjacent to each other along the surfaces 3a and 3b when viewed from the side. That is, the retroreflective structure 3B is a structure in which a plurality of minute cylinders or spheres are arranged adjacent to each other along one direction.
The light L10a incident on the surface 3a is transmitted through the surface 3a, refracted by the surface 3a at a refraction angle corresponding to the curvature thereof, and proceeds toward the reflection surface 12a of the unit structure 10 as light L10b. The light L10b incident on the reflection surface 12a is reflected by the reflection surface 12a and travels toward the surface 3a as 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. Light is emitted as light L10e.

  According to the first retroreflecting part 2A provided with the retroreflective structures 3A and 3B, the incident angle and the outgoing angle are equal, so that the light incident on the first retroreflective part 2A is 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 portion 2A is arranged with the surface 3b side of the retroreflective structure 3A or the retroreflective structure 3B facing the first light source S1.

  The material of the first retroreflective portion 2A allows the first light L1 to pass therethrough, and retroreflects light incident on the first retroreflective portion 2A from the first light branching portion 4 side (that is, the side opposite to 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. Examples thereof include optical glass, polycarbonate resin (PC), and polymethyl methacrylate resin (PMMA). A reflective material (not shown) is provided in contact with the surface 3b side, that is, the reflective surfaces 12a and 12c. As a reflective material, the first light L1 can be transmitted in the emission direction E1, and light incident on the first retroreflecting portion 2A in the opposite direction to the emission direction E1 (for example, the light L16) can be reflected. Substances are used, and examples thereof include dielectric substances.

In addition, if the light which injects into the 1st retroreflection part 2 can be reflected in the same direction as an incident direction, the structure and material of the 1st retroreflection part 2 will not be specifically limited.
For example, the first retroreflective portion 2 may be a full corner cube, a cat eye retroreflective material, a combination of a lenticular lens and a reflector, or a lens in which single lenses are arranged vertically and horizontally (so-called fly's eyes). Lens, fly-eye lens) combined with a reflector, a hologram copied retroreflective performance, a spatial light modulator (SLM), an acoustic light modulator (AOM), etc. A digital hologram, a phase conjugate mirror, etc., which are possible and programmed with a retroreflective function. Examples of the full corner cube include a known prism type reflection sheet (for example, see http://www.yao-sangyo.co.jp/sign/prism — 4090.html) and crystal grade (registered trademark, for example, http: // /Www.carbide.co.jp/jp/view/file/product/4c74f1d8ac72dfc26d1e3588c0358529.

  The first light branching portion 4 reflects a part of the first light L1 transmitted through the first retroreflecting portion 2A toward the second retroreflecting portion 6 as the first reflected light L2, and the second retroreflecting portion 6 At least a part of the reflected first reflected light L2 is transmitted. The 1st light branching part 4 is arrange | positioned in the predetermined position of a user's observation position side from 1st light source S1 and 1st retroreflection part 2A. The first light branching unit 4 is, for example, a half mirror, but reflects at least a part of the first reflected light L2 reflected by the first retroreflecting unit 2A that reflects a part of the first light L1 as described above. If it can permeate | transmit, it will not specifically limit. As such a first light branching portion 4, in addition to a half mirror, for example, a plate-like member made of acrylic or glass, or a hollow body made of these materials and containing water in a hollow, punching metal, etc. Examples thereof include a plate having an aperture array, a wire grid film, a reflective polarizing film, and other materials generally called a beam splitter.

  The second retroreflective portion 6 is disposed 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 portion 4. The position P6 of the second retroreflecting unit 6 is in the emission direction E2, and the position PS1 of the first display D1, the position P2 of the first retroreflecting unit 2A, and the position P4 of the first light branching unit 4 are taken into consideration. It is appropriately set at a position where one reflected light L2 can be incident.

  The 2nd retroreflection part 6 is equipped with the well-known retroreflection structure. That is, the structure and material of the second retroreflecting unit 6 include the same structure and material as the first retroreflecting unit 2 described above, but the light incident on the second retroreflecting unit 6 is in the same direction as the incident direction. If it can be reflected, it will not be specifically limited. However, since it is not necessary for the second retroreflective portion 6 to transmit the first reflected light L2, for example, when the retroreflective structures 3A and 3B are employed, as the reflective material provided on the surface 3b side, that is, the reflective surfaces 12a and 12c. In addition to the above-described dielectric materials, for example, aluminum, gold, silver, and the like can be given.

In the display device 1A of the first embodiment, a part of the light L11 out of the first light L1 emitted from the first light source S1 is reflected as the reflected light L12 (first reflected light L2) by the first light branching unit 4. Reflected. The reflected light L12 enters the second retroreflecting unit 6, is reflected by the second retroreflecting unit 6 in the same direction as the incident direction, and enters the first light branching unit 4 as reflected light L13, and the first light branching. The aerial image I is formed at a position Q1 that is transmitted through the portion 4 and symmetrical to the first light source S1 with respect to the plate surface (that is, the reflection surface) of the first light branching portion 4.
Of the first light L1, the light L15 is reflected by the first light branching section 4, and then enters the first retroreflecting section 2A as reflected light L16 (first reflected light L2), and the first retroreflecting. A position Q1 that is reflected by the portion 2A in the same direction as the incident direction, passes through the first light branching portion 4, and is symmetrical to the first light source S1 with respect to the plate surface (that is, the reflecting surface) of the first light branching portion 4. An aerial image I is formed.
For example, the light L18 (first light L1) emitted from the first light source S1 disposed at one end of the first display D1 is reflected by the first light branching unit 4, and then reflected light L19 ( The first reflected light L2) is incident on the first retroreflecting portion 2A, reflected by the first retroreflecting portion 2A in the same direction as the incident direction, transmitted through the first light branching portion 4, and the first light branching portion 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 reflection surface).

  According to the display device 1A of the first embodiment described above, the user can add a conventional display device in addition to a certain area Z1 in the space A (that is, the space where the user is located with respect to the first light splitting unit 4). Then, the aerial image I can also 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 area Z1 and the area Z2 from the observation direction E0 opposite to the first light source S1 with respect to the first light branching section 4. Accordingly, the angle θ1A at which the aerial image I can be seen on the display device 1A can be increased. As can be seen from 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, the brightness of the aerial image I can be improved.

(Second embodiment)
Next, the display device 1B according to the second embodiment of the present invention will be described. In addition, in the components of the display device 1B of the second embodiment shown in FIG. 4, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

As shown in FIG. 4, the display device 1B includes a first light source S1, a first retroreflecting unit 2A, a first light branching unit 4 arranged to face the first retroreflecting unit 2A, A wave plate 21, a second wave plate 22, and a first polarization branching unit 25 are provided.
Further, the display device 1B is configured such that the first reflected light L2 enters the first retroreflective portion 2A.

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

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

The first polarization branching portion 25 is disposed between the first light source S1 and the first wave plate 21 on the first emission axis J1. Therefore, in the display device 1B, along the emission direction E1 of the first light L1, the first display D1, including the first light source S, the first polarization branching unit 25, the first wavelength plate 21, the first retroreflecting unit 2A, The 2nd wavelength plate 22 and the 1st light branching part 4 are arrange | positioned so that it may mutually oppose. Among these, it is preferable that the first display D1, the first polarization branching unit 25, the first wave plate 21, the first retroreflective unit 2A, and the second wave plate 22 are very close to each other and in contact with each other. It may be integrated.
The first polarization branching unit 25 is configured to be able to transmit P-polarized light and reflect S-polarized light, and is, for example, a reflective polarization beam splitter.

  In the display device 1B of the second embodiment, among the first light L1 emitted from the first light source S, only the P-polarized first light L1 is transmitted through the first polarization branching portion 25 and along the emission direction E1. The light passes through the first wave plate 21, the first retroreflective portion 2, and the second wave plate 22 in this order, and becomes S-polarized first light L 1 and is emitted. A part of the S-polarized first light L1 emitted from the second wave plate 22 is reflected by the first light branching section 4 as the first reflected light L2. The S-polarized first reflected light L2 passes through the second wave plate 22, enters the second retroreflecting unit 6, is reflected by the second retroreflecting unit 6 in the same direction as the incident direction, and is again the second wave plate. 22 and enters the first light branching section 4 as the P-polarized reflected light L3 and is transmitted through the first light branching section 4 to the plate surface (that is, the reflecting surface) of the first light branching section 4. Thus, an aerial image I is formed at a 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 opposite to the first light source S1 with respect to the first light branching portion 4. Accordingly, the angle θ1B at which the aerial image I can be seen in the display device 1B of the second embodiment extends over the entire region of the first light source S1 arranged in the first display D1, and the angle θ1B can be increased. . As can be seen from FIG. 4, the formation of the aerial image I is performed on 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 on the first display D1. Can contribute.

  Moreover, 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 is provided. 4 is a reflective polarizing film, a polarizing plate or a half mirror provided with a polarizing film, etc., so that the first light branching unit 4 blocks the transmitted light directly. The display D1 (ie directly transmitted light) is not visible. Accordingly, it is possible to prevent a reduction in the visibility of the aerial image I due to the mixture of the aerial image I and the first light source S1.

  In addition, according to the display device 1B of the second embodiment, the second retroreflecting unit 6 is omitted, and the first light source S1, the first polarization branching unit 25, and the first are arranged along the emission direction E1 of the first light L1. The wave plate 21, the first retroreflecting unit 2 </ b> A, the second wave plate 22, and the first light branching unit 4 can be arranged, and the entire device can be made compact and space-saving.

(Third embodiment)
Next, a display device 1C according to a third embodiment of the present invention will be described. In addition, in the components of the display device 1C of the third embodiment shown in FIG. 5, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As shown in FIG. 5, the display device 1 </ b> C includes a first light source S <b> 1, a first retroreflecting unit 2 </ b> A, a first light branching unit 4, a first wavelength plate 21, a second wavelength plate 22, A polarization splitter 25, a second light source S2, a second retroreflector 7, a second light splitter 5, a third wavelength plate 23, a fourth wavelength plate 24, a second polarization splitter 26, It has.

  The second light source S2 is, for example, an LED like the first light source S1, but is not particularly limited. In addition, 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 with the light emission directions aligned with each other. The number of 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 a direction E3 (hereinafter, referred to as an emission direction E3) opposite to the emission direction E2 of the first reflected light L2.

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

  The second light branching unit 5 transmits a part of the second light L21 that has passed through the second retroreflective unit 7, and transmits at least a part of the second light L21 that has passed through the second retroreflective unit 7 as a second reflected light. Reflected as L22.

The third wave plate 23 is disposed between the second light source S2 and the second retroreflecting unit 7 on the third emission axis J3. The fourth wavelength plate 24 is disposed at a position in the emission direction E3 of the second light L21 with reference to the second retroreflecting portion 7 on the third emission axis J3.
Similarly 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. This is a so-called λ / 4 plate.

The second polarization branching unit 26 is disposed between the second light source S2 and the third wave plate 23 on the third emission axis J3. 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 unit 26, the third wavelength plate 23, the second retroreflecting unit 7, The fourth wavelength plate 24 and the second light branching portion 5 are appropriately arranged. Among these, it is preferable that the second display D2, the second polarization branching portion 26, the third wavelength plate 23, the second retroreflecting portion 7, and the fourth wavelength plate 24 are very close to each other, and are in contact with each other. It may be integrated.
The second polarization branching unit 26 is configured to reflect P-polarized light and transmit S-polarized light, and is, for example, a reflective polarization beam splitter.

  As can be seen from FIG. 5, the display device 1 </ b> C of the third embodiment is the same as the display device 1 </ b> B of the second embodiment, in which the first display D <b> 1 including the first light source S <b> 1, the first polarization branching unit 25, the first wavelength. The configuration including the plate 21, the first retroreflective portion 2 </ b> A and the second wave plate 22, and the relative position of the first light branching portion 4, the first display D <b> 1 and the first retroreflective in the display device 1 </ b> A of the first embodiment In the same manner as the relative position between the portion 2A and the first light branching portion 4, the same configuration is arranged so as to face these configurations.

  In the display device 1 </ b> C of the third embodiment, only the P-polarized first light L <b> 1 out of the first light L <b> 1 emitted from the first light source S <b> 1 passes through the first polarization branching portion 25 and extends along the emission direction E <b> 1. The light passes through the first wave plate 21, the first retroreflective portion 2, and the second wave plate 22 in this order, and becomes S-polarized first light L 1 and is emitted. A part of the S-polarized first light L1 emitted from the second wave plate 22 is reflected by the first light branching section 4 as the first reflected light L2. The S-polarized first reflected light L2 passes through the second wave plate 22, enters the second retroreflecting unit 6, is reflected by the second retroreflecting unit 6 in the same direction as the incident direction, and is again the second wave plate. 22 and enters the first light branching section 4 as the P-polarized reflected light L3 and is transmitted through the first light branching section 4 to the plate surface (that is, the reflecting surface) of the first light branching section 4. Thus, an aerial image I1 is formed at a position Q1 symmetrical to the first light source S1.

  On the other hand, out of the second light L21 emitted from the second light source S2, only the S-polarized second light L21 is transmitted through the second polarization branching portion 26 and emitted along the emission direction E3. Then, the light passes through the second retroreflecting unit 7 and the fourth wavelength plate 24 in this order, and becomes P-polarized first light L21 to be emitted. A part of the P-polarized first light L1 emitted from the fourth wavelength plate 24 is reflected by the second light branching unit 5 as the first reflected light L2. The P-polarized first reflected light L2 passes through the fourth wavelength plate 24, enters the second retroreflecting unit 7, is reflected by the second retroreflecting unit 7 in the same direction as the incident direction, and again becomes the fourth wavelength plate. 24 passes through the second light branching portion 5 as S-polarized reflected light L3, and passes through the second light branching portion 5 to the plate surface (that is, the reflecting surface) of the second light branching portion 5. Thus, 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 view the aerial image I1 (for example, a character image) from the observation direction E0 opposite to the first light source S1 with respect to the first light branching unit 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 opposite to the second light source S2 with respect to the second light branching unit 5. As described above, according to the display device 1C of the third embodiment, the aerial images I1 and I2 can be multi-viewed.
In the arrangement in which the polarization directions of the transmitted light in the first light branching section 4 and the second light branching section 5 described above are orthogonal, 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 branching section 4, and the first light source S1 and the first display D1 (that is, the directly transmitted light) are branched from the observation direction E10 behind the aerial image I10. It can be observed through part 5. That is, the two-layer multiview of the aerial image and the directly transmitted light as the background is made.
On the other hand, when the first light branching unit 4 and the second light branching unit 5 are arranged so that the polarization directions of the transmitted light are parallel, for example, the second light branching unit 5 is arranged to transmit only the P-polarized component. Accordingly, when the second polarization branching unit 26 is arranged so as to transmit only the P-polarized light component, the first light source S1, the first display D1 (that is, the directly transmitted light), and the second light source. S2 and the second display D2 (that is, directly 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. .
Although FIG. 5 shows multi-viewing in two directions, multi-viewing in three or more directions is possible by installing the display device 1B so as to face each other in each observation direction.
The angle at which the aerial images I1 and I2 are visible extends over the entire region of the first light source S1 disposed on the first display D1 and the entire region of the second light source S2 disposed on the second display D2. Can be bigger. Further, regardless of the position of the first light source S1 on the first display D1 and the position of the second light source S2 on the second display D2, the first light L1 and the second light source S2 of P-polarized light 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.

  In addition, according to the display device 1C of the third embodiment, the first light branching section 4 and the second light branching section 5 may be a reflective polarizing film, a polarizing plate or a half mirror provided with a polarizing film, and the like. Since the directly transmitted light is blocked by the first light branching section 4 and the second light branching section 5, the user cannot see the first light source S and the first display D1 (that is, the directly transmitted light). Accordingly, it is possible to prevent a reduction 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 a display device 1D that 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, the first of the display device 1C. The structure including the wave plate 21 and the second wave plate 22, the first polarization branching unit 25, the second light source S2, the second retroreflecting unit 7, the third wave plate 23, the fourth wave plate 24, and the second The configuration including the polarization branching unit 26 and the configuration in which they are close to each other are provided. Therefore, in the display device 1D, the second light branching unit 5 is omitted.

  According to the display device 1D that is a modified example of the third embodiment, the angle at which the aerial image I can be seen is the second light source disposed on the first light source S1 or the second display D2 disposed on the first display D1. This extends over the entire region S2, and can be increased. In addition, by installing the first polarization branching unit 25 so that the direct light of the first display D1 is transmitted through the first light branching unit 4, the user can connect the second light source S2 to the first light branching unit 4. From a certain direction E0 on the opposite side, a background (for example, the character image “U”) by 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, the aerial image I and the direct image can be double-layered.

(Fourth embodiment)
Next, a display device 1E according to a fourth embodiment of the invention will be described. In addition, in the components of the display device 1E of the fourth embodiment shown in FIG. 7, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As illustrated in FIG. 7, the display device 1E includes a first light source S1, a first retroreflecting unit 2, a first light branching unit 4, a second light source S2, and a second retroreflecting unit 7. ing. In the configuration of the display device 1A, the display device 1E is configured such that the second retroreflective portion 7 is provided at the position of the second retroreflective portion 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 by the first light branching unit 4 as the first reflected light L2. The first reflected light L2 enters the second retroreflecting unit 6, is reflected by the second retroreflecting unit 6 in the same direction as the incident direction, enters the first light branching unit 4 as reflected light L3, and the first An aerial image I1 is formed at a position Q1 that is transmitted through the light branching portion 4 and symmetrical to the first light source S1 with respect to the plate surface (that is, the reflection 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 unit 4. The first reflected light L2 enters the second retroreflecting unit 6, is reflected by the second retroreflecting unit 6 in the same direction as the incident direction, enters the first light branching unit 4 as reflected light L3, and the first An aerial image I2 is formed at a position Q10 that is transmitted through the light branching portion 4 and symmetrical to the second light source S2 with respect to the plate surface (that is, the reflection surface) of the first light branching 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 the direction E0 opposite to the first light source S1 with respect to the first light branching unit 4. Both second light sources S2 (ie directly transmitted light) can be seen. On the other hand, the user views both the aerial image I2 and the first light source S1 (that is, directly transmitted light) of the display D1 from the observation direction E10 opposite to the second light source S2 with respect to the second light branching unit 5. Can see. As described above, according to the display device 1C of the third embodiment, it is possible to achieve multi-view 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 area of the first light sources S1 and S2 arranged in the first displays D1 and D2, respectively, and becomes larger. Also, the first light L1 emitted from the first light source S1 and the second light source S2 are emitted regardless of the position of the first light source S1 on the first display D1 and the position of the second light source S2 on the second display D2. Almost all of the second light L21 can contribute to the formation of the aerial images I1 and I2.

(Fifth embodiment)
Next, a display device 1F according to a fifth embodiment of the invention will be described. In addition, in the components of the display device 1F of the fifth embodiment shown in FIG. 8, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As shown in FIG. 8, the display device 1 </ b> F includes a first light source S <b> 1, a first retroreflecting unit 2 </ b> B, a first light branching unit 4, and a second retroreflecting unit 6.

In the display device 1F, the first retroreflective portion 2B is opposite to the emission direction E1 with reference 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. Arranged on the side.
The 2nd retroreflection part 6 is arrange | positioned so that the outer periphery of the 1st retroreflection part 2B and the outer periphery of the 1st light branching part 4 may be connected.
However, since it is not necessary to transmit the first light L1 and the first reflected light L2 in the first retroreflective portion 2B, for example, when the retroreflective structures 3A and 3B are adopted, the surface 3b side, that is, the reflective surfaces 12a and 12c is used. Examples of the reflective material provided include aluminum, gold, silver and the like in addition to the above-described dielectric material. That is, the 1st retroreflection part 2B and the 2nd retroreflection part 6 may be provided with the same retroreflection structure.

In the above arrangement, the first light source S <b> 1 is arranged in the space X surrounded by the first retroreflecting unit 2 </ b> B, the first light branching unit 4, and the second retroreflecting unit 6.
In the third display D3 having the first light source S1, that is, the position PS1 of the first light source S1, the non-arranged portion NS of the first light source S1 can transmit the first light and the first reflected light L2. As such a third display D3, for example, what is called a transparent display or a see-through display can be cited. Specifically, for example, a liquid crystal display with a transparent pixel without a color filter or a part of the display can be made transparent with an organic EL. Examples include a panel in which the non-arranged portion NS can be seen through, or a panel (a so-called ribbon LED or the like) composed of a plurality of LEDs arranged in a striped manner at intervals.

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 unit 4. The first reflected light L2 enters the first retroreflecting part 2B, is reflected in the same direction as the incident direction by the first retroreflecting part 2B, partially passes through the non-arranged part NS of the third display D3, The light enters the first light branching section 4, transmits the first light branching section 4, and is in the air at a position Q1 symmetrical to the first light source S1 with respect to the plate surface (that is, the reflecting surface) of the first light branching section 4 Image I is formed.
Moreover, after the 1st light L18 which injected into the 1st light branch part 4 with the comparatively small incident angle among the 1st light L1 is reflected by the 1st light branch part 4, reflected light L28 (1st reflected light) L2) is incident on the second retroreflecting unit 6, reflected by the second retroreflecting unit 6 in the same direction as the incident direction, transmitted through the first light branching unit 4, and the plate surface of the first light branching unit 4 (that is, , The aerial image I is formed at a 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 opposite to the first light source S1 with respect to the first light branching unit 4. The angle at which the aerial image I can be seen on the display device 1 </ b> F covers substantially the entire plate surface of the first light branching portion 4, and can be made larger than that of a conventional display device or the like. As can be seen from 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, the brightness of the aerial image I can be improved.

(Sixth embodiment)
Next, a display device 1G according to a sixth embodiment of the present invention will be described. In the constituent elements of the display device 1G of the sixth embodiment shown in FIG. 9, the same constituent elements as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

As illustrated in FIG. 9, the display device 1G includes a fourth display D4 including a first light source S1 and a first retroreflecting unit 2C, a first light branching unit 4, and a second retroreflecting unit 6. I have.
Further, the display device 1G is configured such that the first reflected light L2 enters the first retroreflective portion 2C.

In the display device 1G, the fourth display D4 includes a first light source S1 and a first light source S1 arranged on the surface 35a of the substrate 35 so as to be spaced apart from each other (that is, the first light source S1 is not disposed). The first retroreflective portion 2C is disposed in the portion NS). With such a configuration, the first retroreflective portion 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. That is, at the same positions PS1 and P2, as shown in FIG. 10, the plurality of light sources S1 and the first retroreflective portion 2C are arranged in a space division.
In addition, since it is not necessary to transmit the 1st light L1 and the 1st reflected light L2 in the 1st retroreflection part 2C, when the retroreflection structure 3A, 3B is employ | adopted, for example, the surface 3b side, ie, reflection surface 12a, 12c, is used. Examples of the reflective material provided include aluminum, gold, silver and the like in addition to the above-described dielectric material.

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 branching section 4. . The first reflected light L2 incident on the first retroreflective portion 2C is reflected in the same direction as the incident direction by the first retroreflective portion 2C, passes through the first light branching portion 4, and is a plate of the first light branching portion 4. An aerial image I is formed at a position Q1 symmetrical to the first light source S1 with respect to the surface (that is, the reflection surface).
Moreover, after the 1st light L18 which injected into the 1st light branch part 4 with the comparatively small incident angle among the 1st light L1 is reflected by the 1st light branch part 4, reflected light L28 (1st reflected light) L2) is incident on the second retroreflecting unit 6, reflected by the second retroreflecting unit 6 in the same direction as the incident direction, transmitted through the first light branching unit 4, and the plate surface of the first light branching unit 4 (that is, , The aerial image I is formed at a 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 opposite to the first light source S1 with respect to the first light branching unit 4. 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 light branching section 4, and can be made larger than that of a conventional display device or the like. As can be seen from 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, the brightness of the aerial image I can be improved.

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

According to the display device 1H which is the first modified example of the sixth embodiment, it is possible to obtain the same function 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 a substantially orthogonal direction.
The angle formed by the surfaces of the first light branching section 4 and the fourth display D4 is not limited to approximately 45 °, and can be set to an arbitrary angle. The aerial image I is positioned at a position corresponding to the angle. It is formed.

  A 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, as shown in FIG. However, the first retroreflective portion 2C maintains the relative relationship of being 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 disposed between the first light source S1 on the first emission axis J1 and the first retroreflective portion 2C.

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

According to the display device 1K that is the second modification of the sixth embodiment, the same operational effects as those of the display device 1G that is the first modification of the sixth embodiment can be obtained. Moreover, according to the display device 1K which is the second modification of the sixth embodiment, the polarizing plate 40 is provided, and the polarizing film is provided on the reflective polarizing film, the polarizing plate, and the half mirror as the first light branching portion 4. Since the direct light is blocked by the first light branching unit 4 by using an object or the like, the first light source S1 (that is, the direct transmitted light) and the fourth display D4 are not visible to the user. Accordingly, it is possible to prevent a reduction in the visibility of the aerial image I due to the mixture of the aerial image I and the first light source S1.
In the display device 1G of the sixth embodiment shown in FIG. 9 as well, the first retroreflective portion 2C is positioned at 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. If the polarizing plate 40 is disposed between the first light source S1 on the first emission axis J1 and the first retroreflective portion 2C, the transmitted light is directly blocked as described above, and only the aerial image I is present. Observed.

(Seventh embodiment)
Next, a display device 1V according to a seventh embodiment of the invention will be described. In addition, in the components of the display device 1V of the seventh embodiment shown in FIG. 13, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As illustrated in FIG. 13, the display device 1 </ b> V includes a first display D <b> 1 that includes the first light source S <b> 1, a first light branching unit 4, and a first retroreflecting unit 2 </ b> A.

In the display device 1V, the first retroreflective portion 2A is disposed at a position on the second reflection axis J2 indicating the emission direction E2 of the first reflected light L2.
Moreover, the 1st light branching part 4 protrudes on the opposite side to the side where the 1st light source S1 and the 1st retroreflection part 2A are arrange | positioned with respect to the 1st light branching part 4 as it goes to a center from an outer periphery. Is curved.

  According to the display device 1V of the seventh embodiment described above, as in the display device 1A of the first embodiment, the user is in the space A (that is, the space where the user is located with respect to the first light branching section 4). An 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 retroreflecting unit 6, and the configuration of the device can be simplified as compared with the display device 1A of the first embodiment. Furthermore, in the display device 1 </ b> V according to the seventh embodiment, the aerial image I can be easily disposed at a substantially right angle with respect to a tangent line passing through the apex of the first light branching portion 4 that curves. Accordingly, when the first light source S1 and the first retroreflecting unit 2A are removed from the observation direction E0 and the aerial image I is viewed from the observation direction E0, the first light source S1 and the virtual image of the first light source S1 are not seen. Thus, the aerial image I can be easily viewed.

(Eighth embodiment)
Next, a display device 1W according to an eighth embodiment of the present invention will be described. In addition, in the components of the display device 1W of the eighth embodiment shown in FIG. 14, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As illustrated in FIG. 14, the display device 1W includes a first display D1 including a first light source S1, a first wavelength plate 21, a first retroreflecting unit 2A, a first reflecting plate 50A, and a first light. The branch part 4 and the 2nd reflecting plate 50B are provided.

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

  The second reflecting plate 50B extends in the same direction as the extending direction of the first reflecting plate 50A from the front end e4 of the first reflecting plate 50A with the first light branching portion 4 interposed therebetween. Is the same. Further, the second reflecting plate 50B reflects at least a part of the first reflected light L2 reflected by the first retroreflecting unit 2A and transmits the other part. The second reflecting plate 50B corresponds to, for example, a known half mirror, but is not particularly limited as long as it can reflect the first reflected light L2. The second reflecting plate 50B may be a total reflection mirror that reflects all of the first reflected light L2 reflected by the first retroreflecting unit 2A. The second reflecting plate 50B only needs to reflect at least part of the first reflected light L2, and may be a transparent plate (glass desk mat or the like). For example, when a desk mat is used as the second reflecting plate 50B, an aerial image I appears to float on the desk while seeing something like the grain of the desk.

  In the display device 1W according to the eighth embodiment described above, among the first light L1 emitted from the first light sources S1 of the first display D1, the light directed toward the first reflecting plate 50A is the first reflecting plate 50A. And is reflected toward the first wave plate 21 by the first light branching portion 4 made of a reflective polarizing plate or the like. One of the P-polarized light and the 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 that has passed through the first light branching portion 4 is reflected as retroreflected light (reflected light) L13 by the second reflecting plate 50B and is directly irradiated from the first retroreflecting portion 2A. At the same time, an aerial image I is formed. As shown in FIG. 14, a virtual image of the first display D1 is generated on the opposite side of the first display D1 across the first reflectors 50A and 50B.

  Therefore, according to the display device 1W of the eighth embodiment, similarly to the display device 1A of the first embodiment, the user is in the space A (that is, the space where the user is located with respect to the first light splitting unit 4). An aerial image I can be observed. For example, when the first reflecting plate 50A and the second reflecting plate 50B are installed on a table such as a table, an aerial image I rising substantially vertically from the above-described table can be obtained, and the aerial image I can be easily observed. If a half mirror is used as the second reflector 50B and a transparent base is used, a virtual image can be observed simultaneously with the aerial image I.

(Ninth embodiment)
Next, a display device 1P according to a ninth embodiment of the present invention will be described. In addition, in the components of the display device 1P of the ninth embodiment shown in FIG. 15, the same components as those of the display device 1A of the first embodiment shown in FIG. The description is omitted.

  As illustrated 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 light branching unit 4A and the second light branching unit 4B are arranged to face each other with the first light source S1 interposed therebetween. In other words, the first light source S1 is disposed between the first light branching portion 4A and the second light branching portion 4B that are disposed to face each other. The emission part (not shown) of the first light source S1 is directed to the space formed between the first light branching part 4A and the second light branching part 4B. The first light branching portion 4A and the second light branching 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. In the second light branching portion (one light branching portion) 4B, the first retroreflecting portion 2A is provided on the surface opposite to the surface (side) facing the first light branching 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 branching portion 4A and the second light branching portion 4B, and the first light branching is performed. It hits the part 4A or the second light branching part 4B and is transmitted. When the first light L1 is applied to the first retroreflective portion 2A, it is returned to the first light source S1 as the retroreflected light 13 in the direction along the surface of the second light branching portion 4B. Thereby, a plurality of aerial images I are formed in a direction substantially orthogonal to the surface of the first light branching portion 1A at a position facing the first light source S1 across the first light branching portion 1A.

  In addition, a virtual image is formed on the virtual line L113 which extended the light L111 reflected by the 2nd light branching part 4B to the 1st retroreflection part 2A side. That is, a plurality of virtual images are formed at positions facing the first light source S1 across the second light branching portion 1B.

  Therefore, according to the display device 1P of the ninth embodiment, similarly to the display device 1A of the first embodiment, the user is provided with the first light source S1 for the space A (that is, the first light branching section 4). A plurality of aerial images I can be observed in the space on the opposite side to the side where the light is present. Thereby, the multistage aerial image I can be easily formed 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 that is a first modification of the display device 1P of the ninth embodiment. In the display device 1P, the second light source S2 is arranged in the space formed between the first light branching portion 4A and the second light branching portion 4B in the display device 1P with a space from the first light source S1. It is. The emission part (not shown) of the second light source S2 is directed to the space formed between the first light branching part 4A and the second light branching part 4B, and the direction in which the emission part of the second light source S2 is directed. 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 reversing the direction orthogonal to the surfaces of the first light branching portion 4A and the second light branching 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, the aerial image I is generated from each light source by using the first light source S1 and the second light source S2, and the aerial image I The number can be easily increased. If the virtual images of the respective light sources are also utilized, the number of aerial images I can be further increased.

  In the display device 1P, the first retroreflective portion 2A is in contact with the second light branching portion 4B. However, like the display device 1P ′ shown in FIG. 17, the first retroreflective portion 2A is the second light branching portion 4B. May be arranged with a predetermined interval. As described above, the display device 1 </ b> P has a degree of freedom in arrangement of components. Further, in the display device 1P, both surfaces of a single transparent acrylic plate or transparent glass plate can be used as 4A and 4B. For example, if an LED is arranged on a sash of a glass window and a curtain of a retroreflective sheet is attached to the glass window, the aerial image I multiplexed from the outside can be observed. Furthermore, by arranging another retroreflective portion at a position where the observation of the aerial image I is not hindered on the first light branching portion 4A side, the aerial image I can be formed also for the light ray L111.

  FIG. 18 shows a display device 1R that is a second modification of the display device 1P of the ninth embodiment. In the display device 1R, the surface of the first light branching portion 4A of the display device 1N is inclined with respect to the direction along the surface of the second light branching portion 4B. In the configuration example shown in FIG. 18, the first light branching portion 4A is separated from the second light branching portion 4B as it proceeds from the left side to the right side of the drawing.

  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 formed on the respective surfaces of the first light branching portion 4A and the second light branching portion 4B. It is formed on a virtual circumference centered on a virtual intersection where the extension lines intersect. Although the display device 1R is an example, the position of the aerial image I, that is, a plurality of the first light sources S1, is adjusted by adjusting the opposing arrangement and the angle between the first light branching portion 4A and the second light branching portion 4B in this way. The positions where the real and virtual images are formed can be easily changed. Note that the display device 1P of the ninth embodiment may be provided with an adjustment unit capable of adjusting the arrangement and angle of the first light branching unit 4A and the second light branching unit 4B.

  Further, although not shown, the display device 1P and the display devices 1Q, 1P ′, 1R of the modifications thereof use a light source (for example, a point light source, an LED, etc.) that can emit the spot-like 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 a plurality of people, it has been necessary to enlarge the kaleidoscope itself so that a plurality of people can look at it simultaneously. However, by arranging the aerial image I like a pattern that can be seen with a kaleidoscope using the display device 1P or the like, a kaleidoscope pattern can be formed in the air and can be observed simultaneously by a plurality of people.

(Tenth embodiment)
Next, a display device 1T according to a tenth embodiment of the present invention will be described. In addition, in the constituent elements of the display device 1T according to the tenth embodiment shown in FIGS. 20 to 23, the same constituent elements as those of the display device 1A according to the first embodiment shown in FIG. A description thereof will be omitted.
FIG. 19 shows a known display device CT.

  The display device 1T according to the tenth embodiment includes a backlight 55 including a plurality of first light sources S1, a first liquid crystal panel 51, a first polarizing plate 40A, a first light branching unit 4, and a first retroreflective unit. 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 the rear of the first emission axis J1 indicating the emission direction E1 of the first light L1. In the backlight 55, the first light source S1 is arranged with the emitting portion facing the first polarizing plate 40A side. 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 disposed at a position on the first emission axis J1. The first polarizing plate 40A is disposed between the first display D1 and the first liquid crystal panel 51 on the first emission axis J1.

  The first light branching section 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 part 2A. The first retroreflective portion 2A is disposed 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-described configuration, a second liquid crystal panel 52 is disposed 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 light 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 (or a multilayer liquid crystal). A half mirror can be used for the first light branching section 4.

  In the display device CT, among 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 is transmitted through the first polarizing plate 40A, and the first liquid crystal is displayed. 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 by the first light branching section 4 as the first reflected light L2. The first reflected light L2 is retroreflected as retroreflected light L13 by the first retroreflecting portion 2A, passes through the first light branching portion 4, and forms an aerial image I with the first light branching portion 4 interposed therebetween.

  As shown in FIG. 20, in the display device 1T (2) of the tenth embodiment, the first recursion on the second emission axis J2 in the configuration of the display device 1T (2) as shown in FIG. A first wave plate 21 is disposed 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 direction of the reflective polarizing plate forming the first light branching portion 4 is parallel to the direction of the first polarizing plate 40A. That is, the first light branching portion 4 and the first polarizing plate 40B are arranged so as to have a parallel Nicols (or parallel Nicols) relationship. With such an arrangement, the first light L1 emitted from the second polarizing plate 40B has a crossed Nicols relationship with the first light branching portion 4, and hardly transmits through the first light branching portion 4, The light is reflected as the first reflected light L2 by the one light branching section 4. After passing through the first wave plate 21 and entering the first retroreflecting unit 2A, the retroreflected light L13 reflected by the first retroreflecting unit 2A has a parallel Nicol relationship with the first optical branching unit 4. Thus, the aerial image I is formed through the first light branching portion 4.

  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 from the configuration of the above-described display device 1T (1), and the first wavelength plate The optical axis 21 is arranged so as to be parallel to the width direction of the backlight 55 including the first light source S1, that is, along the direction forming 45 degrees with respect to the polarization direction of the first polarizing plate 40A. Yes. Therefore, in the display device 1T (2), the first light branching portion 4 and the first polarizing plate 40A are arranged so as to have a parallel Nicol (or parallel Nicol) relationship. The first light L1 emitted from the first liquid crystal panel 51 maintains a parallel Nicol relationship with respect to the first light branching unit 4. The first reflected light L2 reflected by the first light branching portion 4 passes through the first wave plate 21 and enters the first retroreflecting portion 2A. Thereafter, the retroreflected light L13 reflected by the first retroreflective portion 2A is in a parallel Nicol relationship again with respect to the first light branching portion 4, passes through the first light branching portion 4, and forms an aerial image I. To do.

  As shown in FIG. 22, in the display device 1T (3) which is another example of the tenth embodiment, the second polarizing plate 40B on the first emission axis J1 is used in the configuration of the display device 1T (1) described above. A first wave plate 21 is disposed in front. A second wave plate 22 is disposed behind the first retroreflective portion 2A on the second emission axis J2. In the configuration example of FIG. 22, the first wavelength plate 21 is disposed in the vicinity of the surface of the second polarizing plate 40 </ b> B on the first light branching portion 4 side, and the second wavelength plate 22 is the first light branching portion 4. It arrange | positions in the vicinity of the surface by the side of the 1st retroreflection part 2A. Furthermore, the direction of the reflective polarizing plate forming the first light branching portion 4 is orthogonal to the direction of the first polarizing plate 40A. That is, the first light branching portion 4 and the first polarizing plate 40A are arranged so as to form a crossed Nicols (or vertical Nicols) relationship. That is, the optical axes of the first wave plate 21 and the second wave plate 22 are arranged at 45 degrees with respect to the polarization direction of the second polarizing plate 40B.

  Accordingly, 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 wavelength plate 21, and the second wavelength plate 22, respectively, and the first light branching. A crossed Nicol relationship is established with respect to part 4. The first reflected light L2 reflected by the first light branching portion 4 passes through the second wave plate 22 and enters the first retroreflecting portion 2A. Thereafter, the retroreflected light L13 reflected by the first retroreflective portion 2A passes through the second wavelength plate 22 again, and is in a parallel Nicol relationship with the first optical branching portion 4, so that the first optical branching portion 4 And an aerial image I is formed.

  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 axis is obtained. The first wave plate 21 is disposed in front of the first liquid crystal panel 51 on J1. The direction of the reflective polarizing plate forming the first light branching portion 4 is orthogonal to the direction of the first polarizing plate 40A, and the first light branching portion 4 and the first polarizing plate 40A are crossed Nicols (or vertical). Nicole) is arranged. 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 are 45 degrees with respect to the optical axis of the first liquid crystal panel 51. Yes.

  Accordingly, 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 branching unit 4. Make a Nicole relationship. The first reflected light L2 reflected by the first light branching portion 4 passes through the second wave plate 22 and enters the first retroreflecting portion 2A. Thereafter, the retroreflected light L13 reflected by the first retroreflective portion 2A passes through the second wavelength plate 22 again, and is in a parallel Nicol relationship with the first optical branching portion 4, so that the first optical branching portion 4 And an aerial image I is formed.

  According to the display device 1T of the tenth embodiment described above, as in the display device 1A of the first embodiment, the user is in the space A (that is, the space where the user is located with respect to the first light splitting unit 4). An aerial image I can be observed. Moreover, 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 the normal liquid crystal display is deleted. 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. Therefore, the user can easily see the aerial image I, and the user can easily see the aerial image and the secure aerial display and multilayer display Can be realized.

The aerial image display method to which the present invention is applied emits the first light L1 from the first light source S, and transmits the first light L1 from the first retroreflecting unit 2 at a position on the first emission axis J1. A step of reflecting at least a part of the first light L1 transmitted through the first retroreflecting unit 2 by the first light branching unit 4 as the first reflected light L2 toward the first retroreflecting unit 2; Transmitting at least part of the first reflected light L2 retroreflected by the retroreflecting unit 2 from the first light branching unit 4.
According to the aerial image display method described above, the aerial image I can be observed from a wider angle.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific embodiments, and various modifications are possible within the scope of the gist of the present invention described in the claims. Deformation / change is possible.

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

  The surface of the fifth display D5 is partitioned into an S wave light emitting unit SS1 that emits S wave polarized first light L1 and a P wave light emitting unit SP1 that emits P wave polarized first light L1. For example, a combination of an LED light source and a polarizing plate capable of emitting S-polarized light can be used as the S-wave light emitting unit SS1, but it is not particularly limited. The P-wave light emitting unit SP1 may be, for example, a combination of an LED light source and a polarizing plate that can emit 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 above-described display device 1M, the polarization of the first light L1 is adjusted by the S wave or the P wave for each predetermined region in the plane of the fifth display D5, and as shown in FIG. In addition to the aerial image I by P or the aerial image I by P wave polarization, a direct image by P wave polarization or S wave polarization on the fifth display D5 can be seen. Since the aerial image and the direct image are separated for each pixel, two layers of images can be displayed independently while using a single display D5. Therefore, the display device 1M can be applied to DFD (Depth-fused 3D) display in which the depth is perceived at a position corresponding to the luminance ratio of each of the S wave light emitting unit SS1 and the P wave light emitting unit SP1.

  As a modification of the display device 1M, a display device 1N shown in FIG. 25 is given. The display device 1N omits the first wave plate 21 and the second wave plate 22 from the configuration of the display device 1M, and instead uses the fifth display D5 (first light source S1) and the first light on the first emission axis J1. A 3D film 44 is disposed between the retroreflective portion 2A. Examples of the 3D film 44 include a parallax barrier, a parallax barrier, a lenticular lens, and the like.

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

  In the display device according to the present invention, an imaging element may be disposed between the first light source S1 and the first retroreflective portion 2 on the first emission axis J1. Examples of the imaging element include a lenticular lens and a fly-eye lens. A three-dimensional display may be used as a display including the first light source S1 and the second light source S2.

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 1 </ b> B according to the present invention is accommodated in the housing 30. Specifically, the first light source S <b> 1, the first display D <b> 1, the first retroreflecting unit 2, and the first wave plate 21 of the display device 1 </ b> B 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. On the upper surface of the housing 30, a reflective polarizing plate (or a reflective polarizing sheet or the like) is provided as the first light branching portion 4.
One of the P-polarized light and the S-polarized light of the first light L1 emitted from the first light source S1 is reflected by the first light branching unit 4, passes through the first wave plate 21, and recursively by the first retroreflecting unit 2. Reflected and transmitted through the first wave plate 21 again. At this time, the polarization of the first light L <b> 1 is changed, and the first light L <b> 1 is incident on and transmitted through the first light branching unit 4 as the other of the P-polarized light and the S-polarized light to form an aerial image I. Therefore, the user can observe the aerial image I from a certain direction E0. Such a display device can be carried, can flexibly cope with the location and installation conditions, and can show the aerial image I to the user.

  In the display device according to the present invention, a prism sheet may be disposed in front of the first light source S1 on the first emission axis J1 or a display equipped with the above-described light source. Here, the prism sheet not shown is a prism sheet in which a plurality of prism structures having a triangular cross section are arranged in a predetermined direction of a base (base material). Examples of the prism structure include a right-angled triangular cross-section where the right-angled portion contacts the base material side, a right-angled triangular cross-section where the long side contacts the base material, and an isosceles triangular shape. There is no particular limitation as long as it can be obtained. Such a prism sheet can be provided in the first light source S1, the second light source S2, the 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 a display equipped with the above-described 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 no prism sheet is provided. be able to. In addition, the edge portion of the aerial image I may be blurred due to light scattering or diffraction. However, the edge of the aerial image I can be sharpened by using a prism sheet.

  Further, in front of the first light source S1 on the first emission axis J1 or a display equipped with the above-described light source, a plurality of layers having the same type and the same pitch of the prism structure or different ones may be provided. Good. Thereby, the refraction direction of the first light L1 can be set finely.

  In addition, the display device according to the present invention can be configured such that the housing 30 is omitted from the display device shown in FIG. 26 as illustrated in FIG. If there exists f) in FIG. 24, it can utilize as a contact determination apparatus based on many scattered light being detected. Conventionally, when scattered light is to be detected, the camera CC is placed at the position indicated by the broken line in FIG. 24 and shooting is performed. However, by placing the camera CC at the position indicated by the solid line in FIG. Any object contact with the image I can be detected and determined sensitively.

  Next, examples carried out to support the effects of the display device according to each embodiment of the present invention will be described. In addition, this invention is not limited to a following example.

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

(Example 2)
In order to configure the display device 1E shown in FIG. 7, two first displays D1 similar to those in Example 1 were used. For the second retroreflective portion 6, the same retroreflective sheet as that of the first retroreflective portion 2 was used.
In the constructed display device 1E, when, for example, the letter “A” is displayed on the first display D1, and the letter “B” is displayed on the first display D1, as viewed in the observation direction E0, as shown in FIG. In this case, the aerial image I of the letter “A” and “B” by the second light source S2 of the second display D2 are visible, and when viewed from the observation direction E10, the aerial image I of the letter “B” and the first image 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 portion 2C, a corner cube type retroreflective sheet (product name: retroreflective sheet QR-1 with retardation film, manufacturer: SN Partners Inc.) provided with the retroreflective structure 3A 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”, for example, is displayed on the fourth display D4, it is confirmed that the first light source S1 and the aerial image I of the character “T” are observed as shown in FIG. did.

Further, instead of the retroreflective sheet having the retroreflective structure 3A, a bead type retroreflective sheet (product name: ultra-high brightness reflective sheet 7610, manufacturer: 3M Co., Ltd.) having the retroreflective structure 3B is used to display 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 light branching section 4 is inclined with respect to the surface of the fourth display D4 (that is, the first light source S1 and the first retroreflecting section 2C) at approximately 45 °. By arranging, the display device 1H shown in FIG. 11 was configured.
In the constructed display device 1H, for example, when the character “T” is displayed on the fourth display D4, it is confirmed that the first light source S1 and the aerial image I of the character “T” are observed as shown in FIG. did.

(Example 5)
In the display device 1H of Example 4, the first retroreflective portion 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. The display device 1H illustrated in FIG. 11 is configured by disposing the polarizing plate 40 between the first light source S1 and the first retroreflective portion 2C. For the polarizing plate 40, a polarizing film (product name: polarizing film HN42, manufacturer: Polaroid) was used.
In the constructed display device 1H, for example, when the character “T” is displayed on the fourth display D4, the first light source S1 of the character “T” is displayed by the first light branching unit 4 and the polarizing plate 40 as shown in FIG. 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. Three LED tapes were used in which three LEDs were arranged at intervals in the width direction, and a plurality of LEDs were arranged at predetermined intervals in the length direction. For the first retroreflective portion 2C, a corner cube type retroreflective sheet (product name: Nikkalite Crystal Grade, manufacturer: Nippon Carbide Industries, Ltd.) having the retroreflective structure 3A was used. 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.
In the constructed display device 1P, as shown in FIG. 34, 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.

  Furthermore, as shown in FIG. 16, in order to constitute the display device 1Q provided with the first light source S1 and the second light source S2, an LED tape having LEDs arranged on both sides was used. Such a double-sided LED tape corresponds to the one in which the first light source S1 and the second light source S2 shown in FIG. 16 are spaced apart from each other by the thickness dimension of the tape substrate. 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.

(Comparative Example 1, Example 7)
In order to configure the display device 1T shown in FIGS. 20 to 23, a special color display (first liquid crystal display 51 and second display 52) provided with a plurality of LEDs emitting visible light was 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-intensity LED panel (pitch 4 mm, surface mount package type, product name: P4-LED panel, distributor: WAN Color) A TFT TFT liquid crystal panel (product name: LTM10C348S, manufacturer: Toshiba Corporation) was used. For the first retroreflective portion 2A, a retroreflective sheet (product name: Nikkalite Crystal Grade, manufacturer: Nippon Carbide Industries Co., Ltd.) having a size of the unit structure 10 of about 180 μm and made of a transparent plastic was used. . A commercially available half mirror (both reflectance and transmittance is about 50%) or a reflective polarizing film (product name: SHM-2, manufacturer: SN Partners Co., Ltd.) is pasted on the transparent acrylic plate for the first light branching section 4 I used what I put on. For the first polarizing plate 40A and the second polarizing plate 40B, a polarizing plate obtained by disassembling the above-mentioned polysilicon TFT liquid crystal panel or a polarizing plate commercially available as a single unit (product name: HN42, manufacturer: Polaroid) is used. used. Commercially available λ / 4 plates were used for the first wave plate 21 and the second wave plate 22.

The display device CT shown in FIG. 19 and the display device 1T shown in FIGS. 20 to 23 are constructed using the above-described components, respectively, and formed from the color image shown in FIG. 36 displayed on the special color display. Each aerial image I is taken by an imaging 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: Corporation). The image was taken using a camera equipped with Nikon). The F value of the imaging camera was 4.8, and the shutter speed during imaging was 1/10 (ISO: 400).
Note that both FIG. 36 and FIG. 41 are 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 captured using a half mirror as the first light branching unit 4 as shown in FIG.

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

  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 substituted for the first polarizing plate 40A. And by not using the 2nd polarizing plate 40B, the loss of the 1st light L1 was suppressed and as shown in FIG. 39, the aerial image I clearer than FIG. 38 was imaged.

Moreover, 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 captured.
Furthermore, in the constructed display device 1T (4), the above-described reflective polarizing film is used as the first polarizing plate 40A, and the first wave plate 21 and the second wave plate 22 are not used without using the second polarizing plate 40B. As shown in FIG. 41, the aerial image I which is brighter than the aerial image I of the display device 1T (3) shown in FIG.

(Example 8)
In the display device 1T (2) constructed in the seventh embodiment, the first liquid crystal panel 51 displays an image of the letter “F” composed of a single color, and the second liquid crystal panel 52 displays “B” composed of a single color. An aerial image I was displayed when an image of the character of was displayed. The F value of the imaging camera was changed to 3.5, and the shutter speed during imaging was kept 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. The aerial image I taken from the front direction is the brightest and clearest, but it is confirmed that the aerial image I can clearly read the letters "F" and "B" even when taken from the left and right directions. did. From the left and right, parallax corresponding to the distance between the two layers was observed, and it was confirmed that a deep aerial image I was formed.

  In the above-described configuration, instead of the characters “F” and “B”, a band-shaped single-color dot pattern (drawing) in which the density continuously changes in the horizontal 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 respective aerial images I shown in FIGS. 45, 46, and 47 were formed. The monochromatic dot pattern was observed to have a depth in the oblique 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 disposed between the first liquid crystal panel 51 and the second liquid crystal panel 52 on the first emission axis J1. Thus, a color tone correction test was conducted. 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 incident light.

  FIG. 49 shows a photograph of an 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 disposed between the first liquid crystal panel 51 and the second liquid crystal panel 52 on the first emission axis J 1, and the optical axis of the wave plate 53 is the width direction of the backlight 55. The aerial image I when the wave plate 53 is arranged so as to be along a direction of 45 degrees with respect to is shown. As can be seen from FIG. 50, when the wave plate 53 is arranged, the coloring phenomenon due to wavelength dispersion is eliminated, and the color of the portion where the red aerial image I was formed before the wave plate 53 is arranged is Disappeared. That is, FIG. 49 and FIG. 50 are both shown as grayscale images, but the “colored portion” shown in FIG. 50 is darker than the “colored portion” shown in FIG. It is possible to confirm the elimination of the above-mentioned coloring phenomenon.

  As can be understood from the embodiments described above, according to the display device to which the present invention is applied, it is understood that the aerial image I can be observed from a wider angle, and the operational effects 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 wave plate 22 ... second wave plate 23 ... 3rd wavelength plate 24 ... 4th wavelength plate 50A ... 1st reflecting plate 50B ... 2nd reflecting plate E1, E2 ... Outgoing direction L1 ... 1st light L2 ... 1st reflected light L21 ... 2nd light S1 ... 1st light source S2 ... Second light source

Claims (20)

A first light source;
A first retroreflecting portion disposed at a position on the first emission axis indicating the emission direction of the first light emitted from the first light source;
First reflecting at least a part of the first light emitted from the first light source as a first reflected light and transmitting at least a part of the first reflected light retroreflected by the first retroreflective portion. An optical branch,
A display device comprising:   2. The display device according to claim 1, wherein the first retroreflective portion is disposed in an emission direction of the first light with respect to the first light source on the first emission axis, and is capable of transmitting the first light. . The first retroreflective portion is disposed on the opposite side of the first light emission direction with respect to the first light source on the first emission axis,
2. The non-arranged portion of the first light source is capable of transmitting the first light and the first reflected light at a position where the first light source is disposed on the first emission axis. Display device.   The display device according to claim 1, wherein the first retroreflective portion is disposed at a position where the first light source is disposed on the first emission axis.   The display device according to claim 1, wherein the first reflected light is incident on the first retroreflective portion. The first reflected light is incident on the first retroreflecting portion;
A first wave plate disposed between the first light source and the first retroreflective portion on the first emission axis;
A second wave plate disposed in the emission direction of the first light with reference to the first retroreflecting portion on the first emission axis;
A first polarization branching unit disposed between the first light source on the first output axis and the first wave plate, and capable of transmitting a specific polarization;
With
The display device according to claim 5, wherein the first wave plate and the second wave plate give a phase difference of (π / 2) in an electric field vibration direction of light incident on each of the first wave plate and the second wave plate.   6. The device according to claim 1, further comprising a second retroreflective portion disposed at a position on the second emission axis indicating an emission direction of the first reflected light reflected by the first light branching portion. The display device described in 1. A first wave plate disposed between the first light source and the first retroreflective portion on the first emission axis;
A second wave plate disposed in the emission direction of the first light with reference to the first retroreflecting portion on the first emission axis;
A first polarization branching unit disposed between the first light source on the first output axis and the first wave plate, and capable of transmitting a specific polarization;
A second light source that emits second light to the opposite side of the emission direction of the first reflected light reflected by the first light branching portion;
A second retroreflective portion that is disposed at a position on the third emission axis indicating the emission direction of the second light, and capable of retroreflecting the first reflected light and transmitting the second light;
Reflecting at least part of the second light transmitted through the second retroreflecting part as second reflected light and transmitting at least part of the second reflected light retroreflected by the second retroreflective part. A two-light branch,
A third wave plate disposed between the second light source on the third emission axis and the second retroreflective portion;
A fourth wavelength plate disposed in the emission direction of the second light with reference to the second retroreflective portion on the third emission axis;
A second polarization branching unit that is disposed between the second light source on the third emission axis and the third wave plate and is capable of transmitting polarized light orthogonal to the specific polarized light;
With
The said 1st wave plate, said 2nd wave plate, said 3rd wave plate, and said 4th wave plate give the phase difference of ((pi) / 2) to the electric field vibration direction of the light which injects into each. Display device. A second light source that emits second light to the opposite side of the emission direction of the first reflected light reflected by the first light branching portion;
2. A second retroreflective portion that is disposed at a position on a third emission axis that indicates an emission direction of the second light, and that can retroreflect the first reflected light and transmit the second light. The display device described in 1.   The display device according to claim 2, wherein an imaging element is disposed between the first light source on the first emission axis and the first retroreflective portion. Emitting the first light from the first light source, and transmitting the first light from the first retroreflective portion at a position on the first emission axis indicating the emission direction of the first light;
Reflecting at least a part of the first light transmitted through the first retroreflecting portion toward the first retroreflecting portion as first reflected light by the first light branching portion;
Transmitting at least part of the first reflected light retroreflected by the first retroreflective portion from the first light branching portion;
An aerial image display method comprising: A first light source;
A first light branching portion that reflects at least a part of the first light emitted from the first light source as first reflected light;
A first retroreflecting portion disposed at a position on the second reflection axis indicating the emission direction of the first reflected light reflected by the first light branching portion;
With
The first light branching portion is convex on the opposite side of the first light branching portion from the side where the first light source and the first retroreflective portion are disposed as it goes from the outer periphery to the center. A curved display device. A first light source;
A first wave plate extending from a first side of the first light source along a first emission axis indicating an emission direction of the first light emitted from the first light source;
A first retroreflective portion provided on the side opposite to the side facing the first light source in the first wave plate;
A first reflector extending along the first emission axis from the other side of the first light source;
A first light branching portion provided between the tip of the first wave plate and the tip of the first reflector;
A second reflecting plate extending in the same direction as the extending direction of the first reflecting plate from the tip portion of the first reflecting plate across the first light branching portion;
With
The first wavelength plate is a display device that gives a phase difference of (π / 2) in the electric field oscillation direction of light incident on each of the first wave plates. A first light source;
A first light branching portion arranged to face each other across the first light source, and a second light branching portion,
The emission part of the first light source is directed to a space formed between the first light branching part and the second light branching part,
The first light branching unit and the second light branching unit reflect at least part of the first light emitted from the first light source as first reflected light and at least part of the first reflected light. Reflect
A display device in which a first retroreflective portion is provided on a side opposite to a side facing the other light branching portion in one of the first light branching portion and the second light branching portion. A first light source;
A first liquid crystal panel disposed at a position on the first emission axis indicating the emission direction of the first light emitted from the first light source;
A first polarizing plate disposed between the first light source on the first emission axis and the first liquid crystal panel;
First reflecting at least a part of the first light emitted from the first light source as a first reflected light and transmitting at least a part of the first reflected light retroreflected by the first retroreflective portion. An optical branch,
A first retroreflecting portion disposed at a position on the second emission axis indicating the emission direction of the first reflected light;
A display device comprising: A second liquid crystal panel is disposed between the first polarizing plate and the first liquid crystal panel on the first emission axis;
A second polarizing plate is disposed in front of the first liquid crystal panel on the first emission axis;
A first wave plate is disposed behind the first retroreflective portion on the second emission axis,
The first wave plate gives a phase difference of (π / 2) in the electric field vibration direction of incident light,
The first light branching portion is a reflective polarizing plate,
The display device according to claim 15, wherein the polarization direction of the reflective polarizing plate is parallel to the polarization direction of the first polarizing plate. A second liquid crystal panel is disposed between the first polarizing plate and the first liquid crystal panel on the first emission axis;
A first wave plate is disposed behind the first retroreflective portion on the second emission axis,
The first wave plate gives a phase difference of (π / 2) in the electric field vibration direction of incident light,
The first light branching portion is a reflective polarizing plate,
The direction of polarization of the reflective polarizing plate is parallel to the direction of polarization of the first polarizing plate,
The display device according to claim 15, wherein an optical axis of the first wave plate is arranged in parallel to a width direction of the first light source. A second liquid crystal panel is disposed between the first polarizing plate and the first liquid crystal panel on the first emission axis;
A second polarizing plate and a first wave plate are disposed in front of the first liquid crystal panel on the first emission axis;
A second wave plate is disposed behind the first retroreflective portion on the second emission axis,
The direction of polarization of the reflective polarizing plate is orthogonal to the direction of polarization of the first polarizing plate 4,
The display device according to claim 15, wherein the optical axes of the first wave plate and the second wave plate are arranged perpendicular to the width direction of the first light source. A second liquid crystal panel is disposed between the first polarizing plate and the first liquid crystal panel on the first emission axis;
A first wave plate is disposed in front of the first liquid crystal panel on the first emission axis;
A second wave plate is disposed behind the first retroreflective portion on the second emission axis,
The direction of polarization of the reflective polarizing plate is orthogonal to the direction of polarization of the first polarizing plate 4,
The display device according to claim 15, wherein optical axes of the first wave plate and the second wave plate are arranged in parallel to a width direction of the first light source.   The prism sheet having a plurality of prisms in a direction perpendicular to the first emission axis is disposed in front of the first light source on the first emission axis. 20. The display device according to any one of 19.