Aerial image display system and input system

Abstract

The purpose of the present invention is to provide: a thin aerial image display system capable of displaying an aerial image; and an input device enabling an aerially displayed image to be operated by touch, without touching a screen.　This aerial image display system (10a) includes: a half mirror (12); and a reflection member (14) selected from a group consisting of a recessed-surface mirror, a Fresnel mirror, and a retroreflection member. The reflection member (14) includes a reflective polarizer, and the reflective polarizer forms a reflective surface of the reflection member (14).

Description

Technical Field

[0001] The present invention relates to an aerial image display system and an input system using the aerial image display system.

Background Art

[0002] In recent years, an aerial image display device that displays an image in the air without a screen has been proposed, and it is expected to be used as a promotional display with a high eye-catching effect and an input device that can touch-operate a video displayed in the air without touching the screen.

[0003] An input device that can touch-operate a video displayed in the air is hygienically preferable because it does not touch the screen. Therefore, it is expected to be used as an input device that is touched by an unspecified number of people, an input device used in a medical field, etc. In addition, since an aerial image is difficult to view from other than the front, for example, in an automated teller machine (ATM), it is expected to have an effect of preventing peeping from the surroundings when entering a personal identification number.

[0004] For example, Patent Document 1 describes an optical imaging device for forming a real image of an object to be projected, which includes a polarizer that transmits P-polarized light with a polarization axis parallel to a reference direction and reflects S-polarized light with a polarization axis perpendicular to the reference direction, a first retardation element that converts S-polarized light into circularly polarized light or elliptically polarized light, a mirror that reflects the light that has passed through the first retardation element, a second retardation element that converts the P-polarized light that has passed through the mirror and passed through the first retardation element and transmitted through the polarizer into circularly polarized light or elliptically polarized light, and a retroreflector that retroreflects the light that has passed through the second retardation element.

[0005] The optical imaging device described in Patent Document 1 makes the light from the object to be projected (light projection means) S-polarized and incident on the polarizer, reflects the S-polarized light reflected by the polarizer with the mirror, converts the light into P-polarized light, transmits it through the polarizer, reflects it with the retroreflector, converts the light into S-polarized light, and reflects it to the viewing side by the polarizer, thereby displaying an image of the object to be projected in the air.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] In such an optical imaging device, it is necessary to arrange the polarizer non-parallel to the mirror and the retroreflector (see FIG. 2 etc. of Patent Document 1). Therefore, there is a problem that the device becomes large-sized.

[0008] An object of the present invention is to provide a thin air image display system capable of displaying an air image, and an input device capable of touch-operating an image displayed in the air without touching the screen.

Means for Solving the Problems

[0009] To solve this problem, the present invention has the following configuration. [1] A half mirror, and a reflecting member selected from the group consisting of a concave mirror, a Fresnel mirror, and a retroreflective member, An air image display system in which the reflecting member has a reflective polarizer, and the reflective polarizer constitutes the reflecting surface of the reflecting member. [2] Further, an image display device is provided, The air image display system according to [1], wherein the reflecting member and the half mirror are arranged on the viewing side of the image display device. [3] The air image display system according to [2], further comprising a polarization separation element having a function of separating incident light into polarized lights orthogonal to each other. [4] The aerial image display system according to [3], wherein the polarization separation element has any one of an active retardation layer capable of switching the direction of the slow axis or the magnitude of retardation, a patterned retardation layer having a plurality of two types of regions in which at least one of the direction of the slow axis and the magnitude of retardation is different, an active polarizer capable of switching the direction of the transmission axis or the absorption axis, and a patterned polarizer having a plurality of two types of regions in which the direction of the transmission axis or the absorption axis is different. [5] The reflective polarizer is a reflective circular polarizer, further having an absorption linear polarizer and a retardation plate, The aerial image display system according to [2], wherein an image display device, an absorption linear polarizer, a retardation plate, a reflection member, and a half mirror are arranged in this order. [6] The reflective polarizer is a reflective circular polarizer, further having an absorption linear polarizer and a retardation plate, The aerial image display system according to [2], wherein an image display device, an absorption linear polarizer, a retardation plate, a half mirror, and a reflection member are arranged in this order. [7] The aerial image display system according to [5] or [6], further having an absorption circular polarizer on the viewing side. [8] The reflective polarizer is a reflective circular polarizer, further having an absorption linear polarizer and a retardation plate, The aerial image display system according to [3] or [4], wherein an image display device, an absorption linear polarizer, a retardation plate, a reflection member, a half mirror, and a polarization separation element are arranged in this order. [9] The reflective polarizer is a reflective circular polarizer, The aerial image display system according to [3] or [4], wherein an image display device, a polarization separation element, a half mirror, and a reflection member are arranged in this order.

[10] The aerial image display system according to [9], further having an absorption circular polarizer on the viewing side of the reflection member.

[11] The reflection member has a support, The reflective polarizer is disposed on the surface of the support, On the surface of the reflective polarizer opposite to the support, a coating layer having the same refractive index as the support is disposed. The aerial image display system according to any one of [1] to

[10] , wherein the surface of the support opposite to the reflective polarizer and the surface of the coating layer opposite to the reflective polarizer are flat surfaces parallel to each other.

[12] The aerial image display system according to any one of [1] to

[11] , wherein the reflective polarizer includes a cholesteric liquid crystal layer.

[13] The aerial image display system according to any one of [1] to

[12] , and A non-contact touch sensor, and an input system having the same. [Advantages of the Invention]

[0010] According to the present invention, it is possible to provide a thin-type aerial image display system capable of displaying an aerial image, and an input device capable of touch-operating an image displayed in the air without touching the screen. [Brief Description of the Drawings]

[0011]

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Embodiments for Carrying Out the Invention

[0012] Hereinafter, the present invention will be described in detail. The description of the constituent elements described below may be based on typical embodiments of the present invention, but the present invention is not limited to such embodiments. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value. Also, with respect to angles, "orthogonal" and "parallel" mean a range of exact angles of ±10°, and with respect to angles, "identical" and "different" can be determined based on whether the difference is less than 5°.

[0013] In this specification, the "slow axis" means a direction in which the refractive index is maximum in the plane. Visible light refers to light within the electromagnetic waves that can be seen by the human eye, indicating light in the wavelength range of 380 to 780 nm.

[0014] <Aerial Image Display System> The aerial image display system of the present invention is a half mirror and a reflecting member selected from the group consisting of a concave mirror, a Fresnel mirror, and a retroreflective member, and has an aerial image display system in which the reflecting member has a reflective polarizer, and the reflective polarizer constitutes a reflecting surface of the reflecting member.

[0015] FIG. 1 is a diagram conceptually showing the aerial image display system of the present invention.

[0016] The aerial image display system 10a shown in FIG. 1 has a half mirror 12 and a reflecting member 14.

[0017] The half mirror 12 is a semi-reflective and semi-transmissive half mirror that reflects a part of the incident light and transmits the rest.

[0018] The reflecting member 14 is a reflecting member selected from the group consisting of a concave mirror, a Fresnel mirror, and a retroreflective member. Further, the reflecting member 14 has a reflective polarizer as a reflective layer, transmits light in one polarization state among the incident light, and reflects light polarized orthogonally to this polarization. That is, the reflecting member 14 is a semi-reflective and semi-transmissive reflecting member that reflects a part of the incident light and transmits the rest. Here, the polarizations orthogonal to each other are polarizations located on the back side of the Poincaré sphere with respect to each other, such as the north pole and the south pole on the Poincaré sphere. Specifically, the polarizations orthogonal to each other are, for example, right circular polarization and left circular polarization if they are circular polarizations, and linearly polarized lights orthogonal to each other if they are linearly polarized lights. The reflective polarizer included in the reflecting member 14 may be a reflective linear polarizer or a reflective circular polarizer.

[0019] The reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member. Since these reflecting surfaces are constituted by a reflective polarizer, the reflecting member 14 exhibits the effect of forming an image in the air of the reflected light. The configuration of the reflecting member 14 will be described in detail later.

[0020] The operation of such an aerial image display system 10a will be described. In the example shown in FIG. 1, the aerial image display system 10a is disposed between the object O and the user U with the reflecting member 14 side facing the object O. When the object O is irradiated with light, the light is reflected on the surface of the object O. At this time, as shown in FIG. 1, the light is emitted from each point on the object O so as to spread in various directions. A part of the light reflected by the object O passes through the reflecting member 14. When the reflective polarizer included in the reflecting member 14 is a reflective circular polarizer, among the incident light, the circularly polarized light component having the opposite turning direction to the circularly polarized light component reflected by the reflecting member 14 passes through the reflecting member 14. The light that has passed through the reflecting member 14 is incident on the half mirror 12. Since the reflection by the half mirror 12 is regular reflection, the light is reflected so as to spread further. At this time, the circularly polarized light reflected by the half mirror 12 is converted into circularly polarized light with the opposite turning direction.

[0021] The circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14 again. Since the circularly polarized light reflected by the half mirror 12 has been converted into circularly polarized light with the opposite turning direction, it is reflected by the reflecting member 14 (reflective polarizer). At this time, for example, when the reflecting member 14 is a retroreflective member, the traveling direction of the light reflected by the reflecting member 14 is the direction opposite to the direction parallel to the direction traveling from the half mirror 12 toward the reflecting member 14. Therefore, the light reflected by the reflecting member 14 is condensed. The light reflected by the reflecting member 14 is incident on the half mirror 12, and a part of it passes through the half mirror 12 and is condensed to form an image in the air.

[0022] In this way, light from an object O that is farther from the user U than the aerial image display system 10a forms an image in the space in front of the aerial image display system 10a by the aerial image display system 10a, thereby displaying an aerial image V1 of the object O in the space in front of the aerial image display system 10a. This can be done. Note that the aerial image V1 is a real image formed in the air.

[0023] In the example shown in FIG. 1, the aerial image display system 10a has a configuration in which the reflecting member 14 is arranged on the object O side and the half mirror 12 is arranged on the user U side. However, the present invention is not limited to this, and a configuration in which the half mirror 12 is arranged on the object O side and the reflecting member 14 is arranged on the user U side may also be used. In the case of such a configuration, the reflecting member 14 reflects one polarization component of the light transmitted through the half mirror 12 among the light from the object O. At this time, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, the reflected light is condensed. A part of the light reflected by the reflecting member 14 is reflected by the half mirror 12. At this time, the polarization state of the light reflected by the half mirror 12 is converted into orthogonal polarization. The light reflected by the half mirror 12 enters the reflecting member 14. Since the polarization state of the light reflected by the half mirror 12 is converted into orthogonal polarization, it passes through the reflecting member 14 (reflective polarizer). Since the light transmitted through the reflecting member 14 is condensed, light forms an image in the space in front of the aerial image display system 10a (on the user U side), and the aerial image V1 of the object O can be displayed.

[0024] Here, in the example shown in FIG. 1, the aerial image display system 10a is configured to display an aerial image V1 of an object O arranged behind the aerial image display system 10a. However, the present invention is not limited to this. No.

[0025] FIG. 2 shows another example of the aerial image display system of the present invention. The aerial image display system 10b shown in FIG. 2 includes an image display device 16, a reflecting member 14, and a half mirror 12 in this order.

[0026] The image display device 16 is a known image display device (display). Examples of the image display device include a liquid crystal display device, an organic electroluminescence display device, an LED (Light Emitting Diode) display device, a micro LED display device, and the like. Also, when the aerial image may be a still image, the image display device may be a photograph with a backlight, a printed matter, or the like. In the following description, the organic electroluminescence display device is also referred to as an OLED. OLED is an abbreviation of 'Organic Light Emitting Diode'.

[0027] The half mirror 12 and the reflecting member 14 are arranged on the viewing side of the image display device 16. The half mirror 12 and the reflecting member 14 are as described above.

[0028] The operation of such an aerial image display system 10b will be described. The image display device 16 irradiates light that forms an image. At this time, as shown in FIG. 2, the light is emitted from each point (each pixel) of the image display device so as to spread in various directions. Among the light irradiated by the image display device 16, the polarized light component transmitted by the reflective polarizer passes through the reflecting member 14. The light that has passed through the reflecting member 14 enters the half mirror 12, and a part of it is reflected by the half mirror 12. Since the reflection by the half mirror 12 is regular reflection, the light is reflected so as to spread further. At this time, the circularly polarized light reflected by the half mirror 12 is converted into circularly polarized light with the opposite rotation direction.

[0029] The circularly polarized light reflected by the half mirror 12 is incident on the reflection member 14 again. Since the circularly polarized light reflected by the half mirror 12 is converted into circularly polarized light with the reverse rotation direction, it is reflected by the reflection member 14. At this time, for example, when the reflection member 14 is a retroreflective member, the traveling direction of the light reflected by the reflection member 14 is in the opposite direction to the direction parallel to the direction traveling from the half mirror 12 toward the reflection member 14. Therefore, the light reflected by the reflection member 14 is condensed. The light reflected by the reflection member 14 is incident on the half mirror 12, and a part of it passes through the half mirror 12 and is condensed to form an image in the air.

[0030] In this way, in the aerial image display system 10b, the light irradiated from the image display device 16 forms an image in the space on the reflection member 14 side (downstream side) of the aerial image display system 10b, so that the aerial image V1 of the image displayed by the image display device 16 in the space on the downstream side of the aerial image display system 10b can be displayed. In the present invention, the downstream refers to the downstream in the optical path of the image displayed (irradiated) by the image display device 16.

[0031] Also, in the example shown in FIG. 2, among the light incident on the reflection member 14, the circularly polarized light component that is not reflected by the reflection member 14 and passes through the half mirror 12 is irradiated from the aerial image display system 10b without being reflected by the reflection member 14 and the half mirror 12. The image formed by this light is visually recognized by the user U as a real image that does not float in the air (hereinafter referred to as a "non-floating image").

[0032] That is, in the example shown in FIG. 2, the same image displayed by the image display device 16 is displayed as a non-floating image and an aerial image.

[0033] In the example shown in FIG. 2, the aerial image display system 10b is configured to be arranged in the order of the reflection member 14 and the half mirror 12 from the image display device 16 side, but it is not limited to this, and it may be configured to be arranged in the order of the half mirror 12 and the reflection member 14 from the image display device 16 side. In the case of such a configuration, the reflecting member 14 reflects one polarization component of the light transmitted through the half mirror 12 among the light emitted from the image display device 16. At this time, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, the reflected light is condensed. A part of the light reflected by the reflecting member 14 is reflected by the half mirror 12. At this time, the polarization state of the light reflected by the half mirror 12 is converted into orthogonal polarization. The light reflected by the half mirror 12 enters the reflecting member 14. Since the polarization state of the light reflected by the half mirror 12 is converted into orthogonal polarization, it passes through the reflecting member 14 (reflective polarizer). Since the light transmitted through the reflecting member 14 is condensed, an aerial image of the object O, V1, can be displayed by forming an image of light in the space on the front side (user U side) of the aerial image display system 10b.

[0034] Here, the aerial image display system of the present invention may further include a polarization separation element having a function of separating incident light into orthogonal polarizations. Fig. 3 shows a diagram conceptually showing another example of the aerial image display system of the present invention. The aerial image display system 10c shown in Fig. 3 includes an image display device 16, a reflecting member 14, a half mirror 12, and a polarization separation element 18 in this order.

[0035] The polarization separation element 18 is an element that separates at least a part of the incident light into orthogonal polarizations. Here, the orthogonal polarizations are polarizations located on the back side of each other on the Poincaré sphere, such as the north pole and the south pole on the Poincaré sphere. Specifically, for example, in the case of circular polarization, they are right circular polarization and left circular polarization, and in the case of linear polarization, they are linearly polarized lights orthogonal to each other.

[0036] The half mirror 12, the reflecting member 14, and the polarization separation element 18 are arranged on the viewing side of the image display device 16. The half mirror 12, the reflecting member 14, and the image display device 16 are as described above.

[0037] Such an aerial image display system 10c displays two types of images that are superimposed to form a multiplexed image. Of these two types of images, one image R passes through the half mirror 12, the reflection member 14, and the polarization beam splitter 18 without being reflected by the half mirror 12 and the reflection member 14, and is observed by the user U (see the dashed arrow in FIG. 3). That is, the image R is an image that the user U directly observes of the image displayed by the image display device 16. Hereinafter, for convenience, this image R is also referred to as a non-floating image R.

[0038] The other image V1 is selectively transmitted by the reflection member 14, reflected by the half mirror 12, selectively reflected by the reflection member 14, and is the image V1 observed by the user U. That is, the image V1 has an optical path that reciprocates between the half mirror 12 and the reflection member 14 (see the solid arrow in FIG. 3). Hereinafter, for convenience, this image V1 is also referred to as a virtual image V1. The optical path of the virtual image V1 in this virtual image display system 10c is the same as the optical path of the virtual image V1 of the virtual image display system 10b shown in FIG. 2. As will be described later, the non-floating image R and the virtual image V1 are separated in optical path by the separation of polarization by the polarization beam splitter 18. As will be described later, the non-floating image R and the virtual image V1 are separated in optical path by the separation of polarization by the polarization beam splitter 18. As will be described later, the non-floating image R and the virtual image V1 are separated in optical path by the separation of polarization by the polarization beam splitter 18.

[0039] FIGS. 4 to 6 show an example of an image displayed by the virtual image display system 10c. FIG. 4 is an example of the non-floating image R displayed by the virtual image display system 10c. FIG. 5 is an example of the virtual image V1 displayed by the virtual image display system 10c. FIG. 6 is an example of the superimposed image V2 displayed by the virtual image display system 10c. As shown in FIG. 6, the virtual image display system 10c displays the non-floating image R and the virtual image V1 superimposed. When the user U observes such a superimposed image V2, in the superimposed non-floating image R and virtual image V1, the virtual image V1 is observed to be located in front. In other words, in the superimposed image V2 observed by the user U, the virtual image V1 is observed as if it has risen from the non-floating image R. When the user U observes such a superimposed image V2, in the superimposed non-floating image R and virtual image V1, the virtual image V1 is observed to be located in front. In other words, in the superimposed image V2 observed by the user U, the virtual image V1 is observed as if it has risen from the non-floating image R. When the user U observes such a superimposed image V2, in the superimposed non-floating image R and virtual image V1, the virtual image V1 is observed to be located in front. In other words, in the superimposed image V2 observed by the user U, the virtual image V1 is observed as if it has risen from the non-floating image R. When the user U observes such a superimposed image V2, in the superimposed non-floating image R and virtual image V1, the virtual image V1 is observed to be located in front. In other words, in the superimposed image V2 observed by the user U, the virtual image V1 is observed as if it has risen from the non-floating image R.

[0040] As an example, such an aerial image display system of the present invention is used in a car navigation system. For example, as conceptually shown in FIGS. 4 to 6, a map image is displayed as a non-floating image R, and additional information such as position information, weather, and arrival time is displayed as an aerial image V1. At this time, to the user U, the additional information is visually recognized as floating in front of the map image. As a result, the user U can distinguish the map image and the additional information at a glance in the superimposed image to be observed, and can accurately and quickly find the information necessary for himself / herself.

[0041] Here, in the aerial image display system 10c, the image display device 16 alternately displays the image that becomes the non-floating image R and the image that becomes the aerial image V1 in a time-division manner. Or, the image display device 1 6 spatially divides the image that becomes the non-floating image R and the image that becomes the aerial image V1, for example, in a stripe pattern and alternately arranges and displays them. When the image display device 16 performs time-division display, the polarization separation element 18 separates the incident light into polarizations orthogonal to each other by alternately performing polarization conversion or absorption on the incident light temporally. When the image display device 16 performs spatial-division display, the polarization separation element 18 separates the incident light into polarizations orthogonal to each other by alternately performing polarization conversion or absorption on the incident light spatially, for example, in a stripe pattern.

[0042] When the aerial image display system 10c performs time-division display, at the timing of displaying the non-floating image R, the polarization separation element 18 operates so that the polarization that passes through the half mirror 12 and the reflection member 14 without being reflected by the half mirror 12 and the reflection member 14 is finally emitted to the viewing side, and the polarization that is reflected between the half mirror 12 and the reflection member 14 and makes a round trip is finally absorbed or reflected and not emitted to the viewing side. On the other hand, for the aerial image V1 At the timing to display, the polarization separation element 18 operates so that polarized light that has been reflected between the half mirror 12 and the reflecting member 14 and made one round trip is emitted to the viewing side, and polarized light that has passed through the half mirror 12 and the reflecting member 14 without being reflected by them is absorbed or reflected and does not emit to the viewing side.

[0043] Furthermore, when the aerial image display system 10c performs spatial division display, at the position where the non-floating image R is displayed, the polarization separation element 18 operates so that polarized light that has passed through the half mirror 12 and the reflecting member 14 without being reflected by them is ultimately emitted to the viewing side, and polarized light that has been reflected between the half mirror 12 and the reflecting member 14 and made a round trip is ultimately absorbed or reflected and not emitted to the viewing side. On the other hand, at the position where the aerial image V1 is displayed, the polarization separation element 18 operates so that polarized light that has passed through the half mirror 12 and the reflecting member 14 without being reflected by them is ultimately absorbed or reflected and not emitted to the viewing side. The polarized light reflected between the half mirror 12 and the reflecting member 14 and making one round trip is emitted to the viewing side, and the polarized light transmitted through the half mirror 12 and the reflecting member 14 without being reflected by them is absorbed or reflected and does not emit to the viewing side.

[0044] In this way, the aerial image display system 10c prevents an image that should be displayed as a non-floating image R from being displayed as an aerial image, and prevents an image that should be displayed as an aerial image V1 from being displayed as a non-floating image. The image that becomes the non-floating image R can be prevented from being displayed as a floating image V1. It is possible to display a superimposed image in which the resulting image can be properly viewed as an aerial image V1.

[0045] 3, the polarization separation element 18 is arranged on the viewing side of the reflecting member 14, but the present invention is not limited to this. The polarization separation element 18 may be arranged between the image display device 16 and the reflecting member 14. Alternatively, the polarization separation element 18 may be arranged between the reflecting member 14 and the half mirror 12.

[0046] Also, in the example shown in FIG. 3, the virtual image display system 10c is configured such that the reflection member 14 and the half mirror 12 are arranged in this order from the image display device 16 side. However, the present invention is not limited to this, and the configuration may be such that the half mirror 12 and the reflection member 14 are arranged in this order from the image display device 16 side.

[0047] Hereinafter, the specific configuration of the virtual image display system of the present invention will be described in more detail. First, a virtual image display system that displays a virtual image as shown in FIG. 2 will be described.

[0048] FIG. 7 shows a diagram conceptually showing another example of the virtual image display system of the present invention. The virtual image display system 10d shown in FIG. 7 includes an image display device 16, an absorption type linear polarizer 20, a retardation layer 22, a reflection member 14, and a half mirror 12. Further, the virtual image display system 10d preferably has an absorption type circular polarizer 32 on the viewing side rather than the half mirror 12. The absorption type circular polarizer 32 includes a retardation layer 24 and an absorption type linear polarizer 26. The reflection member 14 of the virtual image display system 10d has, as a reflection type polarizer, a reflection type circular polarizer that transmits circularly polarized light in one rotation direction and reflects circularly polarized light in the other rotation direction.

[0049] The absorption type linear polarizer 20 and the absorption type linear polarizer 26 are known absorption type linear polarizing plates. Also, the retardation layer 22 and the retardation layer 24 are known retardation layers. As shown below, since the retardation layer converts linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light, it is basically a quarter-wave plate.

[0050] The operation of such a virtual image display system 10d will be described. The image display device 16 irradiates light that forms an image (aerial image). At this time, as described above, light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 is transmitted through the absorption-type linear polarizer 20 and converted into linearly polarized light in a certain direction. In the illustrated example, as an example, the absorption-type linear polarizer 20 is assumed to transmit linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light is incident on the retardation layer 22. The retardation layer 22 converts the incident linearly polarized light into circularly polarized light. In the illustrated example, as an example, the retardation layer 22 is assumed to convert linearly polarized light in the vertical direction into right-circularly polarized light.

[0051] This right-circularly polarized light is incident on the reflecting member 14 having a reflective circular polarizer. In the illustrated example, since the reflecting member 14 (reflective circular polarizer) transmits right-polarized light, the right-polarized light incident on the reflecting member 14 is transmitted without being reflected and is incident on the half mirror 12.

[0052] This right-circularly polarized light is incident on the half mirror 12, and a part of it is transmitted. The right-circularly polarized light transmitted through the half mirror 12 is incident on the absorption-type circular polarizer 32. In the illustrated example, since the absorption-type circular polarizer 32 absorbs right-circularly polarized light, the right-circularly polarized light incident on the absorption-type circular polarizer 32 is absorbed. Specifically, the absorption-type circular polarizer 32 has a retardation layer 24 and an absorption-type linear polarizer 26, and the right-circularly polarized light transmitted through the half mirror 12 is converted into linearly polarized light in the vertical direction by the retardation layer 24. Since the absorption-type linear polarizer 26 absorbs linearly polarized light in the vertical direction, the linearly polarized light in the vertical direction is absorbed by the absorption-type linear polarizer 26.

[0053] On the other hand, the remaining light of the right-circularly polarized light incident on the half mirror 12 is reflected by the half mirror 12. At this time, the right-circularly polarized light is converted into left-circularly polarized light by reflection.

[0054] The left circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14. In the illustrated example, since the reflective circular polarizer of the reflecting member 14 transmits right circularly polarized light and reflects left circularly polarized light, the left circularly polarized light incident on the reflecting member 14 is reflected. Further, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, it reflects light so as to condense the light. The left circularly polarized light reflected by the reflecting member 14 is incident on the half mirror 12.

[0055] A part of the left circularly polarized light incident on the half mirror 12 is reflected and converted into right circularly polarized light, passes through the reflecting member 14, and is incident on the retardation layer 22 and converted into linearly polarized light in the vertical direction. This linearly polarized light passes through the absorption-type linear polarizer 20 and is absorbed on the surface of the image display device 16 or the like.

[0056] On the other hand, the remaining left circularly polarized light incident on the half mirror 12 passes through the half mirror 12. The left circularly polarized light that has passed through the half mirror 12 is incident on the absorption-type circular polarizer 32. Since the absorption-type circular polarizer 32 absorbs right circularly polarized light, the left circularly polarized light passes through. In the illustrated example, the absorption-type circular polarizer 32 has a retardation layer 24 and an absorption-type linear polarizer 26, and the left circularly polarized light that has passed through the half mirror 12 is converted into linearly polarized light in a direction perpendicular to the vertical direction (the direction perpendicular to the paper surface, shown as an arrow in the left-right direction for explanation in the illustrated example, and also referred to as linearly polarized light in the left-right direction in the following description) by the retardation layer 24. Since the absorption-type linear polarizer 26 absorbs linearly polarized light in the vertical direction, the linearly polarized light in the left-right direction passes through the absorption-type linear polarizer 26.

[0057] As described above, the aerial image display system 10d irradiates only the light in the optical path that forms the aerial image V1 to the user U side, preventing the image displayed by the image display device 16 from being visually recognized as a non-floating image. Thereby, the image displayed by the image display device 16 can be displayed as the aerial image V1. using the user U side, preventing the image displayed by the image display device 16 from being visually recognized as a non-floating image. Thereby, the image displayed by the image display device 16 can be displayed as the aerial image V1 can be.

[0058] In addition, as a preferred embodiment, the aerial image display system 10d has an absorption-type circular polarizer 32 on the viewing side of the half mirror 12. By having the absorption-type circular polarizer 32, stray light such as the right circular polarization component not reflected by the half mirror 12 can be absorbed by the absorption-type circular polarizer 32, and it is possible to more reliably suppress the visual recognition of unnecessary images caused by the stray light. Further, it is possible to prevent external light from being reflected on the surface of the aerial image display system 10d and becoming so-called glare.

[0059] In addition, as a preferred embodiment, the absorption axis of the absorption-type linear polarizer 20 and the absorption axis of the absorption-type linear polarizer 26 of the aerial image display system 10d are orthogonal to each other. With the above-described configuration, it is possible to further reduce stray light such as a polarization component that could not be completely reflected by the reflecting member 14, which is preferable. However, the configuration is not limited to the above, and for example, there may be a mode in which the absorption axes of the absorption-type linear polarizer 20 and the absorption-type linear polarizer 26 are parallel.

[0060] In addition, it is preferable that the retardation of the retardation layer 22 and the retardation of the retardation layer 24 of the aerial image display system 10d are the same. Also preferably, the wavelength dispersion of the retardation layer 22 and the wavelength dispersion of the retardation layer 24 are the same, and more preferably, both are inverse dispersion. Here, inverse dispersion means that as the wavelength increases, the retardation value at that wavelength increases. With the above-described configuration, it is possible to further reduce stray light such as a polarization component that could not be completely reflected by the reflecting member 14, which is preferable.

[0061] Also, in the aerial image display system 10d, it is preferable to bond each member so that there is no air layer between the members. This is because if an air layer exists, unnecessary reflections may occur at the air interfaces of the members, or in the case of a reflective polarizer, reflections of polarized light that should not be reflected originally may occur, which can cause stray light. For example, in the aerial image display system 10d, when the right circularly polarized light component that was not converted to left circularly polarized light when reflected by the half mirror 12 enters the second reflecting member 14, passes through the reflecting member 14, and heads towards the image display device 16, if this right circularly polarized light is reflected at the surface of the retardation layer 22, it is converted to left circularly polarized light, and then passes through the reflecting member 14, the half mirror 12, and the absorption-type circular polarizer 32, and may become an unnecessary image and be visually recognized by the user U. Also, for the same reason, in the aerial image display system 10d, when there is an air layer between the members, it is preferable to apply an antireflection treatment to the surfaces of the members on the air side. As the antireflection treatment, known methods such as a method of attaching an AR film in which thin films having specific refractive indices and film thicknesses are laminated, and a method of attaching a moth-eye film can be variously used. As described above, regarding reducing the reflection between the members, the same applies to each aspect after FIG. 8.

[0062] FIG. 8 shows a diagram conceptually representing another example of the aerial image display system of the present invention. The aerial image display system 10e shown in FIG. 8 includes an image display device 16, an absorption-type linear polarizer 20, a retardation layer 22, a half mirror 12, and a reflecting member 14. Further, as a preferred aspect, the aerial image display system 10e has an absorption-type circular polarizer 32 on the viewing side rather than the reflecting member 14. In the illustrated example, the absorption-type circular polarizer 32 includes a retardation layer 24 and an absorption-type linear polarizer 26. The reflecting member 14 of the aerial image display system 10e has, as a reflective polarizer, a reflective circular polarizer that transmits circularly polarized light in one rotation direction and reflects circularly polarized light in the other rotation direction.

[0063] The operation of such an aerial image display system 10e will be described. The image display device 16 irradiates light that forms an image (aerial image). At this time, as described above, light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 is transmitted through the absorption-type linear polarizer 20 and converted into linearly polarized light in a certain direction. In the illustrated example, as an example, the absorption-type linear polarizer 20 is assumed to transmit linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light is transmitted through the retardation layer 22 and converted into circularly polarized light. In the illustrated example, as an example, the retardation layer 22 is assumed to convert linearly polarized light in the vertical direction into right-circularly polarized light.

[0064] When this right-circularly polarized light is incident on the half mirror 12, part of the light is reflected and converted into left-circularly polarized light, and then is incident on the retardation layer 22 and converted into linearly polarized light in a direction perpendicular to the vertical direction (the direction perpendicular to the paper surface). Since this linearly polarized light is linearly polarized light in a direction that does not pass through the absorption-type linear polarizer 20, it is absorbed by the absorption-type linear polarizer 20. On the other hand, the remaining light of the right-circularly polarized light incident on the half mirror 12 passes through the half mirror 12 and is incident on the reflecting member 14. In the illustrated example, since the reflecting member 14 reflects right-circularly polarized light, the right-circularly polarized light incident on the reflecting member 14 is reflected and incident on the half mirror 12. Further, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, it reflects light so as to condense the light.

[0065] Part of the right-circularly polarized light incident on the half mirror 12 is reflected. At this time, the right-circularly polarized light is converted into left-circularly polarized light by reflection. On the other hand, the remaining light of the right-circularly polarized light incident on the half mirror 12 passes through the half mirror 12. The right-circularly polarized light that has passed through the half mirror 12 is converted into linearly polarized light by the retardation layer 22, passes through the absorption-type linear polarizer 20, and is absorbed on the surface of the image display device 16 or the like.

[0066] The left circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14. Since the reflective circular polarizer of the reflecting member 14 reflects right circularly polarized light, the left circularly polarized light is transmitted. The left circularly polarized light transmitted through the reflecting member 14 is incident on the absorption type circular polarizer 32. The absorption type circular polarizer 32 transmits while converting circularly polarized light having the same turning direction as the circularly polarized light transmitted through the reflecting member 14 into linearly polarized light. Therefore, in the illustrated example, the absorption type circular polarizer 32 transmits left circularly polarized light. Specifically, the left circularly polarized light transmitted through the reflecting member 14 is incident on the retardation layer 24. The retardation layer 24 converts the incident left circularly polarized light into linearly polarized light in the left-right direction. The linearly polarized light transmitted through the retardation layer 24 is incident on the absorption type linear polarizer 26. The absorption type linear polarizer 26 transmits linearly polarized light in the left-right direction. Thereby, the absorption type circular polarizer 32 transmits while converting circularly polarized light having the same turning direction as the circularly polarized light transmitted through the reflecting member 14 into linearly polarized light.

[0067] As described above, the aerial image display system 10e uses only the light in the optical path that becomes the aerial image V1 to irradiate the user U side, preventing the image displayed by the image display device 16 from being visually recognized as a non-floating image. Thereby, the image displayed by the image display device 16 can be displayed as the aerial image V1.

[0068] Further, as a preferred embodiment, the aerial image display system 10e has the absorption type circular polarizer 32 on the viewing side rather than the reflecting member 14. By having the absorption type circular polarizer 32, stray light such as a right circularly polarized light component that could not be completely reflected by the reflecting member 14 can be absorbed by the absorption type circular polarizer 32, and it is possible to more reliably suppress the visual recognition of unnecessary images caused by the stray light. In addition, it is possible to prevent external light from being reflected on the surface of the aerial image display system 10e and becoming so-called glare.

[0069] Further, in the aerial image display system 10e, the retardation layer 22 is preferably of inverse dispersion. When the retardation layer 22 is of inverse dispersion, the light incident on the reflecting member 14 becomes more ideal circularly polarized light, and stray light can be further reduced, which is preferable. ​For the same reason, the phase difference layer 24 is also preferably of reverse dispersibility.

[0070] Next, a specific configuration of an aerial image display system that displays a superimposed image of a non-floating image and an aerial image as shown in FIG. 3 will be described.

[0071] FIGS. 9 and 10 show diagrams conceptually representing another example of the aerial image display system of the present invention.

[0072] The aerial image display system 10f shown in FIGS. 9 and 10 includes an image display device 16, an absorption-type linear polarizer 20, a phase difference layer 22, a reflection member 14, a half mirror 12, and a polarization beam splitter 18. The reflection member 14 of the aerial image display system 10f has, as a reflection-type polarizer, a reflection-type circular polarizer that transmits circularly polarized light in one rotation direction and reflects circularly polarized light in the other rotation direction.

[0073] Also, in the illustrated example, the polarization beam splitter 18 includes an absorption-type linear polarizer 28 and a phase difference layer 30. As will be described in detail later, the polarization beam splitter 18 is either an active polarizer in which the absorption-type linear polarizer 28 can switch the direction of the transmission axis (absorption axis), or a pattern polarizer having a plurality of regions with different transmission axis (absorption axis) directions, and the phase difference layer 30 is a normal phase difference layer, or the phase difference layer 30 is an active phase difference layer in which the direction of the slow axis or the retardation can be switched, or a pattern phase difference layer having a plurality of regions with different slow axis directions or retardation magnitudes, and the absorption-type linear polarizer 28 is a normal absorption-type linear polarizer.

[0074] When the polarization beam splitter 18 has an active polarizer or an active phase difference layer, the polarization beam splitter 18 can switch between a state in which it transmits one polarization of the incident light and absorbs the polarization orthogonal thereto, and a state in which it transmits the orthogonal polarization and absorbs one polarization. Hereinafter, such a polarization beam splitter 18 is also referred to as a time-division polarization beam splitter 18.

[0075] When the polarization separation element 18 is a time-division polarization separation element 18, the image display device 16 time-divisionally separates the non-floating image R and the aerial image V1 in accordance with the switching operation of the polarization separation element 18. and alternately displays them.

[0076] In such an aerial image display system, when the image display device 16 displays the non-floating image R, the polarization separation element 18 operates so as to transmit only the polarization passing through the optical path for the non-floating image R and not to transmit the polarization passing through the optical path for the aerial image V1, thereby displaying only the non-floating image R. When the image display device 16 displays the aerial image V1, the polarization separation element 18 transmits only the polarization passing through the optical path for the aerial image V1 and does not transmit the polarization passing through the optical path for the non-floating image R, thereby displaying only the aerial image V1. The aerial image display system 10f displays a superimposed image V2 in which the non-floating image R and the aerial image V1 are superimposed by alternately displaying the non-floating image R and the aerial image V1.

[0077] When the polarization separation element 18 has a pattern polarizer or a pattern retardation layer, the polarization separation element 18 has a plurality of regions that transmit one polarization of the incident light and absorb the polarization orthogonal thereto, and regions that transmit the orthogonal polarization and absorb one polarization. Hereinafter, such a polarization separation element 18 is also referred to as a space-division polarization separation element 18.

[0078] When the polarization separation element 18 is a space-division polarization separation element 18, the image display device 16 spatially separates and displays the non-floating image R and the aerial image V1 in accordance with the region division configuration of the polarization separation element 18. For example, when the polarization separation element 18 alternately has regions that transmit one polarization and regions that transmit the other polarization in a stripe pattern, the image display device 16 spatially separates the non-floating image R and the aerial image V1 in a stripe pattern and alternately arranges and displays them.

[0079] In such an aerial image display system, in the area where the image display device 16 displays the non-floating image R, the polarization separation element 18 transmits only the polarized light passing through the optical path of the non-floating image R and does not transmit the polarized light passing through the optical path of the aerial image V1 so as to display only the non-floating image R. In the area where the image display device 16 displays the aerial image V1, the polarization separation element 18 transmits only the polarized light passing through the optical path of the aerial image V1 and does not transmit the polarized light passing through the optical path of the non-floating image R, thereby displaying only the aerial image V1. The aerial image display system 10f displays the superimposed image V2 in which the non-floating image R and the aerial image V1 are superimposed by displaying the non-floating image R and the aerial image V1 for each area.

[0080] The example shown in FIG. 9 shows the timing at which the aerial image V1 is displayed or the state of the area where the aerial image V1 is displayed in the aerial image display system 10f. The operation of the aerial image display system 10f in this state will be described.

[0081] The image display device 16 irradiates light that becomes an image (aerial image). At this time, as described above, the light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 is transmitted through the absorption type linear polarizer 20 and converted into linearly polarized light in a certain direction. In the illustrated example, as an example, the absorption type linear polarizer 20 transmits linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light is incident on the retardation layer 22. The retardation layer 22 converts the incident linearly polarized light into circularly polarized light. In the illustrated example, as an example, the retardation layer 22 converts linearly polarized light in the vertical direction into right circularly polarized light.

[0082] This right circularly polarized light is incident on the reflecting member 14. In the illustrated example, since the reflective circular polarizer of the reflecting member 14 transmits right circularly polarized light and reflects left circularly polarized light, the right polarized light incident on the reflecting member 14 is transmitted without being reflected and is incident on the half mirror 12.

[0083] This right circularly polarized light is incident on the half mirror 12, and a part of it is transmitted. The right circularly polarized light transmitted through the half mirror 12 is incident on the polarization separation element 18. In the illustrated example, since the polarization separation element 18 absorbs right circularly polarized light, the right circularly polarized light incident on the polarization separation element 18 is absorbed. Specifically, the polarization separation element 18 has a retardation layer 30 and an absorption type linear polarizer 28, and the right circularly polarized light transmitted through the half mirror 12 is converted into vertically polarized light by the retardation layer 30. Since the absorption type linear polarizer 28 absorbs vertically polarized light, the vertically polarized light is absorbed by the absorption type linear polarizer 28.

[0084] On the other hand, the remaining light of the right circularly polarized light incident on the half mirror 12 is reflected by the half mirror 12. At this time, the right circularly polarized light is converted into left circularly polarized light by reflection.

[0085] The left circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14. In the illustrated example, since the reflective circular polarizer of the reflecting member 14 reflects left circularly polarized light, the left circularly polarized light incident on the reflecting member 14 is reflected. Further, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, it reflects light so as to condense the light. The left circularly polarized light reflected by the reflecting member 14 is incident on the half mirror 12.

[0086] A part of the left circularly polarized light incident on the half mirror 12 is reflected and converted into right circularly polarized light, and is incident on the reflecting member 14. This right circularly polarized light passes through the reflecting member 14, is converted into linearly polarized light by the retardation layer 22, passes through the absorption type linear polarizer 20, and is absorbed on the surface of the image display device 16 or the like.

[0087] On the other hand, the remaining light of the left circularly polarized light incident on the half mirror 12 passes through the half mirror 12. The left circularly polarized light that has passed through the half mirror 12 is incident on the polarization separation element 18. Since the polarization separation element 18 absorbs right circularly polarized light, the left circularly polarized light passes through. In the illustrated example, the polarization separation element 18 has a retardation layer 30 and an absorption type linear polarizer 28, and the left circularly polarized light that has passed through the half mirror 12 is converted into linearly polarized light in the left-right direction by the retardation layer 30. Since the absorption type linear polarizer 28 absorbs linearly polarized light in the up-down direction, the linearly polarized light in the left-right direction passes through the absorption type linear polarizer 28.

[0088] As described above, the aerial image display system 10f uses only the light in the optical path that becomes the aerial image V1 and irradiates the user U side, preventing the image displayed by the image display device 16 from being visually recognized as a non-floating image. As a result, the image displayed by the image display device 16 can be displayed as the aerial image V1.

[0089] In the aerial image display system 10f, the retardation layer 22 preferably has inverse dispersion. When the retardation layer 22 has inverse dispersion, the light incident on the reflection member 14 becomes more ideal circularly polarized light, and stray light can be further reduced, which is preferable. Also, for the same reason, the retardation layer 30 preferably has inverse dispersion.

[0090] On the other hand, the example shown in FIG. 10 shows the timing of displaying the non-floating image R or the state of the area where the non-floating image R is displayed in the aerial image display system 10f. The operation of the aerial image display system 10f in this state will be described.

[0091] ​The image display device 16 irradiates light that forms an image (non-floating image). At this time, as described above, light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 passes through the absorption-type linear polarizer 20 and is converted into linearly polarized light in a certain direction. As described above, in the illustrated example, as an example, the absorption-type linear polarizer 20 transmits linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light enters the retardation layer 22. The retardation layer 22 converts the incident linearly polarized light into circularly polarized light. As described above, in the illustrated example, as an example, the retardation layer 22 converts linearly polarized light in the vertical direction into right-circularly polarized light.

[0092] This right-circularly polarized light enters the reflecting member 14. In the illustrated example, since the reflective circular polarizer of the reflecting member 14 transmits right-circularly polarized light and reflects left-circularly polarized light, the right-polarized light incident on the reflecting member 14 is transmitted without being reflected and enters the half mirror 12.

[0093] This right-circularly polarized light enters the half mirror 12, and a part of it is transmitted. The right-circularly polarized light transmitted through the half mirror 12 enters the polarization separation element 18. In the illustrated example, since the polarization separation element 18 transmits right-circularly polarized light, this right-circularly polarized light passes through the polarization separation element 18 and is emitted from the aerial image display system 10f. In the illustrated example, the right-circularly polarized light passes through the retardation layer 30 of the polarization separation element 18 and is converted into linearly polarized light in the horizontal direction. That is, in FIGS. 9 and 10, the retardation layer 30 is an active retardation layer or a patterned retardation layer, and in the state shown in FIG. 10, the direction of the slow axis of the retardation layer 30 is different from that in the state shown in FIG. 9, and the right-circularly polarized light transmitted through the retardation layer 30 is converted into linearly polarized light in the horizontal direction orthogonal to the state shown in FIG. 9. The linearly polarized light in the horizontal direction converted by the retardation layer 30 enters the absorption-type linear polarizer 28. Since the absorption-type linear polarizer 28 absorbs linearly polarized light in the vertical direction, the linearly polarized light in the horizontal direction passes through the absorption-type linear polarizer 28.

[0094] On the one hand, a part of the right circularly polarized light reflected by the half mirror 12 is converted into left circularly polarized light by reflection. The left circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14. Since the reflection-type circular polarizer of the reflecting member 14 transmits right circularly polarized light and reflects left circularly polarized light, this left circularly polarized light is reflected. The reflected left circularly polarized light is incident on the half mirror 12.

[0095] A part of the light incident on the half mirror 12 passes through the half mirror 12. The transmitted left circularly polarized light is incident on the polarization separation element 18. Since the polarization separation element 18 transmits right circularly polarized light, the left circularly polarized light is absorbed. Specifically, the left circularly polarized light passes through the retardation layer 30 of the polarization separation element 18 and is converted into vertically linearly polarized light, but since the absorption-type linear polarizer 28 absorbs vertically linearly polarized light, this vertically linearly polarized light is absorbed by the absorption-type linear polarizer 28.

[0096] On the other hand, the left circularly polarized light reflected by the half mirror 12 is converted into right circularly polarized light by reflection, passes through the reflecting member 14, is converted into linearly polarized light by the retardation layer 22, passes through the absorption-type linear polarizer 20, and is absorbed on the surface of the image display device 16 or the like.

[0097] As described above, at the timing when the aerial image display system 10f displays the non-floating image R, or in the area where the non-floating image R is displayed, only the light in the optical path that becomes the non-floating image R is irradiated to the user U side, preventing the image displayed by the image display device 16 from being visually recognized as an aerial image. Thereby, it is possible to prevent the image displayed by the image display device 16 as the non-floating image R from being displayed as an aerial image, and it can be displayed only as the non-floating image R.

[0098] In this way, in the aerial image display system 10f, at the timing or in the area where the image display device 16 displays the non-floating image R, the polarization separation element 18 transmits only the polarization passing through the optical path that becomes the non-floating image R and does not transmit the polarization passing through the optical path that becomes the aerial image V1, so that only the non-floating image R is displayed, and at the timing or in the area where the image display device 16 displays the aerial image V1, The polarization separation element 18 transmits only the polarized light passing through the optical path that becomes the aerial image V1, and does not transmit the polarized light passing through the optical path that becomes the non-floating image R, thereby displaying only the aerial image V1. Aerial image display By not transmitting the polarized light passing through the optical path that becomes the non-floating image R, only the aerial image V1 is displayed. Aerial image display The system 10f displays the non-floating image R and the aerial image V1 by time-division or spatial division, and displays a superimposed image V2 in which the non-floating image R and the aerial image V1 are superimposed.

[0099] The examples shown in FIGS. 9 to 10 are examples in which the polarization separation element 18 is disposed on the viewing side of the half mirror 12 and the reflective polarizer.

[0100] FIGS. 11 and 12 conceptually show another example of the aerial image display system of the present invention.

[0101] The aerial image display system 10g shown in FIGS. 11 and 12 includes an image display device 16, a polarization separation element 18, a half mirror 12, and a reflection member 14. Further, the aerial image display system 10g preferably has an absorption-type circular polarizer 32 on the viewing side of the reflection member 14.

[0102] The example shown in FIG. 11 shows the timing of displaying the aerial image V1 or the state of the area for displaying the aerial image V1 in the aerial image display system 10g. The operation of the aerial image display system 10g in this state will be described. The operation of the aerial image display system 10g in this state will be described.

[0103] The image display device 16 irradiates light that becomes an image (aerial image). At this time, as described above, the light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 passes through the absorption-type linear polarizer 28 of the polarization separation element 18 and is converted into linearly polarized light in a certain direction. In the illustrated example, as an example, the absorption-type linear polarizer 28 transmits linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light passes through the retardation layer 30 of the polarization separation element 18 and is converted into circularly polarized light. In the illustrated example, as an example, the retardation layer 30 converts linearly polarized light in the vertical direction into right-circularly polarized light.

[0104] When this right circularly polarized light is incident on the half mirror 12, part of the light is reflected and converted into left circularly polarized light, and is incident on the retardation layer 30 and converted into linearly polarized light in the left-right direction. Since this linearly polarized light is linearly polarized in a direction that does not pass through the absorption type linear polarizer 28, it is absorbed by the absorption type linear polarizer 28. On the other hand, the remaining light of the right circularly polarized light incident on the half mirror 12 passes through the half mirror 12 and is incident on the reflecting member 14. In the illustrated example, since the reflective circular polarizer of the reflecting member 14 reflects right circularly polarized light, the right circularly polarized light incident on the reflecting member 14 is reflected and incident on the half mirror 12. Further, since the reflecting member 14 is any one of a concave mirror, a Fresnel mirror, and a retroreflective member, it reflects light so as to condense the light.

[0105] Part of the light incident on the half mirror 12 is reflected. At that time, the right circularly polarized light is converted into left circularly polarized light by reflection. On the other hand, the remaining light of the right circularly polarized light incident on the half mirror 12 passes through the half mirror 12. The right circularly polarized light that has passed through the half mirror 12 is converted into linearly polarized light by the retardation layer 30, passes through the absorption type linear polarizer 28, and is absorbed on the surface of the image display device 16 or the like.

[0106] The left circularly polarized light reflected by the half mirror 12 is incident on the reflecting member 14. Since the reflective circular polarizer of the reflecting member 14 reflects right circularly polarized light, the left circularly polarized light passes through. The left circularly polarized light that has passed through the reflecting member 14 is incident on the absorption type circular polarizer 32. The absorption type circular polarizer 32 transmits while converting circularly polarized light in the same turning direction as the circularly polarized light transmitted by the reflecting member 14 into linearly polarized light. Therefore, in the illustrated example, the absorption type circular polarizer 32 transmits left circularly polarized light. Specifically, the left circularly polarized light that has passed through the reflecting member 14 is incident on the retardation layer 24. The retardation layer 24 converts the incident left circularly polarized light into linearly polarized light in the left-right direction. The linearly polarized light that has passed through the retardation layer 24 is incident on the absorption type linear polarizer 26. The absorption type linear polarizer 26 transmits linearly polarized light in the left-right direction. Thereby, the absorption type circular polarizer 32 transmits while converting circularly polarized light in the same turning direction as the circularly polarized light transmitted by the reflecting member 14 into linearly polarized light.

[0107] In this way, in the aerial image display system 10g, at the timing when the image display device 16 displays the aerial image V1, or in the area where the aerial image V1 is displayed, only the light on the optical path that becomes the aerial image V1 is irradiated to the user U side, preventing the image displayed by the image display device 16 from being visually recognized as a non-floating image. As a result, it is possible to prevent the image displayed by the image display device 16 as the aerial image V1 from being displayed as a non-floating image and to display it only as the aerial image V1. In addition, in a preferred embodiment, the aerial image display system 10g has an absorption-type circular polarizer 32 on the viewing side of the reflecting member 14. By having the absorption-type circular polarizer 32, stray light such as the right circular polarization component that could not be completely reflected by the reflecting member 14 can be absorbed by the absorption-type circular polarizer 32, more reliably suppressing the visual recognition of unnecessary images caused by the stray light. Also, it is possible to prevent external light from being reflected on the surface of the aerial image display system 10g and causing so-called glare. In addition, in the aerial image display system 10g, the retardation layer 30 preferably has inverse dispersion characteristics. When the retardation layer 30 has inverse dispersion characteristics, the light incident on the reflecting member 14 becomes more ideal circularly polarized light, and stray light can be further reduced, which is preferable. .

[0108] For the same reason, the retardation layer 24 also preferably has inverse dispersion characteristics.

[0109] On the other hand, the example shown in FIG. 12 shows the state of the aerial image display system 10g at the timing of displaying the non-floating image R or in the area where the non-floating image R is displayed. The operation of the aerial image display system 10g in this state will be described.

[0110]

[0111] ​​The image display device 16 irradiates light that forms an image (non-floating image). At this time, as described above, the light is emitted from each point (each pixel) of the image display device so as to spread in various directions. The light irradiated by the image display device 16 is transmitted through the absorption-type linear polarizer 28 of the polarization separation element 18 and converted into linearly polarized light in a certain direction. In the illustrated example, as an example, the absorption-type linear polarizer 28 transmits linearly polarized light in the vertical direction in the figure. Next, this linearly polarized light is transmitted through the retardation layer 30 of the polarization separation element 18 and converted into circularly polarized light. In the illustrated example, as an example, the retardation layer 30 converts linearly polarized light in the vertical direction into left-handed circularly polarized light. That is, in FIGS. 11 and 12, the retardation layer 30 is an active retardation layer or a patterned retardation layer, and in the state shown in FIG. 12, the direction of the slow axis of the retardation layer 30 is different from that in the state shown in FIG. 11, and the linearly polarized light in the vertical direction transmitted through the retardation layer 30 is converted into left-handed circularly polarized light opposite to that in the case of the state shown in FIG. 11.

[0112] When this left-handed circularly polarized light is incident on the half mirror 12, part of the light is reflected and converted into right-handed circularly polarized light, and is incident on the retardation layer 30 and converted into linearly polarized light in the left-right direction. Since this linearly polarized light is linearly polarized light in a direction that does not pass through the absorption-type linear polarizer 28, it is absorbed by the absorption-type linear polarizer 28. On the other hand, the remaining light of the left-handed circularly polarized light incident on the half mirror 12 passes through the half mirror 12 and is incident on the reflection member 14. However, since it is circularly polarized light with a rotation direction opposite to that of the circularly polarized light reflected by the reflection-type circular polarizer of the reflection member 14, it passes through the reflection member 14.

[0113] The left-handed circularly polarized light that has passed through the reflection member 14 is incident on the absorption-type circular polarizer 32. As described above, the absorption-type circular polarizer 32 converts the incident left-handed circularly polarized light into linearly polarized light in the left-right direction and transmits it.

[0114] As described above, at the timing when the aerial image display system 10g displays the non-floating image R, or in the area where the non-floating image R is displayed, only the light on the optical path that becomes the non-floating image R is irradiated to the user U side, preventing the image displayed by the image display device 16 from being visually recognized as an aerial image. Thereby, it is possible to prevent the image displayed by the image display device 16 as the non-floating image R from being displayed as an aerial image, and it can be displayed only as the non-floating image R.

[0115] In this way, in the aerial image display system 10g, at the timing or in the area where the image display device 16 displays the non-floating image R, the polarization beam splitter 18 transmits only the polarization passing through the optical path that becomes the non-floating image R and does not transmit the polarization passing through the optical path that becomes the aerial image V1, so that only the non-floating image R is displayed. At the timing or in the area where the image display device 16 displays the aerial image V1, the polarization beam splitter 18 transmits only the polarization passing through the optical path that becomes the aerial image V1 and does not transmit the polarization passing through the optical path that becomes the non-floating image R, so that only the aerial image V1 is displayed. The aerial image display system 10g displays the non-floating image R and the aerial image V1 in a time-division or space-division manner to display a superimposed image V2 in which the non-floating image R and the aerial image V1 are superimposed.

[0116] The example shown in FIGS. 11 to 12 is an example in which the polarization beam splitter 18 is arranged between the image display device 16 and the half mirror 12.

[0117] Also, in the examples shown in FIGS. 7 to 12, all the reflecting members 14 are configured to have reflective circular polarizers, but the present invention is not limited to this, and the reflecting member 14 may be configured to have a reflective linear polarizer. In the case where the reflecting member 14 has a reflective linear polarizer, the arrangement of a retardation layer or the like may be appropriately changed so that the light incident on the reflecting member 14 becomes linearly polarized light and the light incident on the half mirror 12 becomes circularly polarized light.

[0118] Next, the components of the aerial image display system will be described.

[0119] (Half mirror) The half mirror is a conventionally known half mirror that transmits about half of the incident light and reflects the remaining about half. The transmittance of the half mirror is preferably 50 ± 30%, more preferably 50 ± 10%, and most preferably 50%. The half mirror is composed of, for example, a resin having transparency such as polyethylene terephthalate (PET), cycloolefin polymer (COP), polymethyl methacrylate (PMMA), or a substrate made of glass or the like, and has a reflective layer made of a metal such as silver or aluminum. The reflective layer made of a metal such as silver or aluminum is formed on the surface of the substrate by vapor deposition or the like. The thickness of the reflective layer is preferably 1 to 20 nm, more preferably 2 to 10 nm, and even more preferably 3 to 6 nm.

[0120] (Reflection member) The reflection member has a reflective polarizer, and this reflective polarizer constitutes the reflection surface of the reflection member. Among the incident light, it transmits light in one polarization state and reflects light polarized orthogonally to this polarization. In addition, the reflection member has a configuration selected from the group consisting of a concave mirror, a Fresnel mirror, and a retroreflective member. Figs. 13 to 15 each show a diagram conceptually representing an example of the reflection member.

[0121] Fig. 13 is a diagram showing a cross section of an example of a reflection member that is a concave mirror. The reflection member 14a shown in Fig. 13 has a transparent support 40a having a concave surface, a reflective polarizer 42a formed on the concave surface of the support 40a, and a coating layer 44a laminated on the surface of the reflective polarizer 42a opposite to the support 40a.

[0122] The support 40a is made of glass, triacetyl cellulose (TAC), polyethylene terephthalate (PET), polycarbonate, polyvinyl chloride, acrylic, polyolefin, etc., and one surface (concave surface) has a concave portion obtained by cutting off a part of a spherical surface or a parabolic surface.

[0123] On the concave surface of the support 40a, a reflective polarizer 42a is laminated. The reflective polarizer 42a has a substantially constant thickness and is laminated along the recess of the support 40a. That is, the reflective polarizer 42a has a concave and curved shape. The reflecting member 14a transmits light in one polarization state through the reflective polarizer 42a, reflects light in a polarization orthogonal to this polarization, and the reflective polarizer 42a has a function of condensing the reflected light due to its concave shape.

[0124] There is no limitation on the reflective polarizer, and various known reflective polarizers can be used. The reflective polarizer is basically a reflective linear polarizer or a reflective circular polarizer.

[0125] A reflective linear polarizer is a polarizer that transmits linearly polarized light in a certain direction and reflects linearly polarized light in a direction orthogonal to this linearly polarized light. Examples of the reflective linear polarizer include a film obtained by stretching a dielectric multilayer film as described in JP-A-2011-053705 and a wire grid polarizer as described in JP-A-2015-028656. Also, commercially available products of reflective linear polarizers can be preferably used. Examples of commercially available reflective linear polarizers include the reflective polarizer (trade name: APF) manufactured by 3M and the wire grid polarizer (trade name: WGF) manufactured by AGC.

[0126] A reflective circular polarizer is a polarizer that transmits right circularly polarized light or left circularly polarized light and reflects circularly polarized light with a rotation direction opposite to that of the transmitted circularly polarized light. Examples of the reflective circular polarizer include a reflective circular polarizer having a cholesteric liquid crystal layer. The cholesteric liquid crystal layer is a liquid crystal phase formed by fixing a cholesterically oriented liquid crystal phase (cholesteric liquid crystal phase).

[0127] As is well known, a cholesteric liquid crystal layer has a helical structure in which liquid crystal compounds are spirally wound and stacked. The structure in which the liquid crystal compounds are spirally wound once (rotated 360°) and stacked is defined as one helical pitch (helical pitch). The liquid crystal compounds that are spirally wound have a structure in which a plurality of pitches are stacked. The cholesteric liquid crystal layer reflects right circularly polarized light or left circularly polarized light in a specific wavelength range and transmits other light, depending on the length of the helical pitch and the sense of the helix of the liquid crystal compound. Therefore, when the aerial image display system displays a color image, the reflective circular polarizer may have a plurality of cholesteric liquid crystal layers, such as a cholesteric liquid crystal layer having a central wavelength of selective reflection for red light, a cholesteric liquid crystal layer having a central wavelength of selective reflection for green light, and a cholesteric liquid crystal layer having a central wavelength of selective reflection for blue light.

[0128] Also, the cholesteric liquid crystal layer may be formed directly on the support 40a having a concave surface, or may be formed on a temporary support and then adhered onto the concave surface of the support 40a. Further, an alignment film for aligning the liquid crystal compounds in the cholesteric liquid crystal layer may be provided between the support 40a and the cholesteric liquid crystal layer.

[0129] The thickness of the reflective polarizer may be appropriately adjusted to a thickness that can sufficiently reflect the polarized light to be reflected and can sufficiently transmit the polarized light to be transmitted, depending on the type of the reflective polarizer and the like.

[0130] Also, the reflecting member 14a in the illustrated example preferably has a coating layer 44a laminated on the surface of the reflective polarizer 42a opposite to the support 40a. The coating layer 44a is preferably transparent. Further, it is preferably made of a material having substantially the same refractive index as the support 40a. Furthermore, the surface of the support 40a opposite to the reflective polarizer 42a and the surface of the coating layer 44a opposite to the reflective polarizer 42a are preferably flat surfaces parallel to each other.

[0131] When there is no coating layer 44a, the light transmitted through the reflecting member is bent by the influence of the concave surface of the support 40a. Therefore, the image of the light transmitted through the reflecting member is subjected to an enlarging or reducing effect. On the other hand, the reflecting member 14a has a coating layer 44a having substantially the same refractive index as the support 40a, and by making the surfaces of the support 40a and the coating layer 44a flat surfaces parallel to each other, it is possible to prevent the light transmitted through the reflecting member 14a from being bent by the influence of the concave surface of the support 40a, and it is possible to prevent the image of the light transmitted through the reflecting member 14a from being subjected to an enlarging or reducing effect. Thereby, in the aerial image display system of the present invention, it is possible to prevent a non-floating image and / or an aerial image from being enlarged, reduced, or distorted.

[0132] The refractive index of the support 40a and the refractive index of the coating layer 44a do not necessarily have to be exactly the same as long as the above effects are obtained, and there may be a difference within the range where the effects are exhibited. The difference between the refractive index of the support 40a and the refractive index of the coating layer 44a is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.01 or less.

[0133] FIG. 14 is a diagram showing a cross section of an example of a reflecting member that is a retroreflective member. The reflecting member 14b shown in FIG. 14 has a transparent support 40b having a corner cube array formed on its surface, a reflective polarizer 42b formed on the corner cube array of the support 40b, and a coating layer 44b laminated on the surface of the reflective polarizer 42b opposite to the support 40b.

[0134] FIG. 15 shows a plan view of an example of a corner cube array, and FIG. 16 shows a perspective view of an example of a corner cube array. As shown in FIGS. 15 and 16, the corner cube array has a structure in which a large number of three-sided mirrors (also called corner cube prisms) where three mirrors intersect at right angles to each other are arranged on a plane. From the viewpoint of improving the resolution of the aerial image, it is preferable that the size of one of the three-sided mirrors is less than 1 mm on each side. The light incident on one of the three-sided mirrors of the corner cube array is sequentially reflected by the mirror surfaces of the three sides and is emitted in the reverse direction parallel to the incident direction. That is, it is retroreflected.

[0135] The support 40b is made of glass, triacetyl cellulose (TAC), polyethylene terephthalate (PET), polycarbonate, polyvinyl chloride, acrylic, polyolefin, etc., and has a corner cube array known as a retroreflective member.

[0136] A reflective polarizer 42b is laminated on the corner cube array of the support 40b. The reflective polarizer 42b has a substantially constant thickness and is laminated along the surface shape of the corner cube array of the support 40b. That is, the reflective polarizer 42b functions as a reflective layer of the corner cube array. The reflective polarizer 42b is a conventionally known reflective circular polarizer or reflective linear polarizer, similar to the reflective polarizer 42a of the reflective member 14a except for having a different shape. The reflective member 14a has a function of transmitting light in one polarization state by the reflective polarizer 42a, reflecting light polarized orthogonally to this polarization, and retroreflecting the reflected light.

[0137] Also, as a preferred embodiment, the reflective member 14b in the illustrated example has a coating layer 44b laminated on the surface opposite to the support 40b of the reflective polarizer 42b. The surface of the support 40b opposite to the reflective polarizer 42b and the surface of the coating layer 44b opposite to the reflective polarizer 42b are flat surfaces parallel to each other. The coating layer 44b is preferably transparent, and the difference between the refractive index of the support 40b and the refractive index of the coating layer 44b is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.01 or less.

[0138] In the illustrated example, the reflecting member 14b is a retroreflective member composed of a corner cube array, but the present invention is not limited to this. In a retroreflective member of the glass bead type, the reflecting surface may be a reflective polarizer.

[0139] FIG. 17 is a cross-sectional view showing an example of a reflecting member of a Fresnel mirror. The reflecting member 14c shown in FIG. 17 includes a transparent support 40c having a groove in the shape of a Fresnel lens, a reflective polarizer 42c formed on the surface of the support 40c where the Fresnel lens is formed, and a coating layer 44c laminated on the surface of the reflective polarizer 42c opposite to the support 40c.

[0140] The support 40c is made of glass, triacetyl cellulose (TAC), polyethylene terephthalate (PET), polycarbonate, polyvinyl chloride, acrylic, polyolefin, etc., and has a known Fresnel lens shape on one surface.

[0141] The reflective polarizer 42c is laminated on the surface of the support 40c where the groove in the shape of a Fresnel lens is formed. The reflective polarizer 42c has a substantially constant thickness and is laminated along the Fresnel lens shape of the support 40a. That is, the reflective polarizer 42c has a Fresnel lens shape. The reflective polarizer 42c is a conventionally known reflective circular polarizer or reflective linear polarizer, similar to the reflective polarizer 42a of the reflecting member 14a except for the different shape. The reflecting member 14c transmits light in one polarization state through the reflective polarizer 42c and reflects light polarized orthogonally to this polarization. Further, since the reflective polarizer 42c has a Fresnel lens shape, it acts as a Fresnel mirror and has a function of condensing the reflected light by the same action as a concave mirror.

[0142] In addition, the reflecting member 14c in the illustrated example preferably has a coating layer 44c laminated on the surface opposite to the support 40c of the reflective polarizer 42c. The surface of the support 40c opposite to the reflective polarizer 42c and the surface of the coating layer 44c opposite to the reflective polarizer 42c are flat surfaces parallel to each other. The coating layer 44c is preferably transparent, and the difference between the refractive index of the support 40c and the refractive index of the coating layer 44c is preferably 0.1 or less, more preferably 0.05 or less, and even more preferably 0.01 or less.

[0143] (Polarization beam splitter element) The polarization beam splitter element has a function of separating at least a part of the incident light into polarizations orthogonal to each other. For example, the polarization beam splitter element separates the incident light into right circular polarization and left circular polarization, or separates it into linearly polarized lights orthogonal to each other. As described above, the polarization beam splitter element preferably has any one of an active retardation layer, a patterned retardation layer, an active polarizer, and a patterned polarizer.

[0144] The active retardation layer is a retardation layer capable of switching the direction of the slow axis or the magnitude of the retardation. As various known active retardation layers for switching the direction of the slow axis, for example, a liquid crystal cell acting as a quarter-wave plate can be used. By switching the applied voltage, an active retardation layer that switches the direction of the slow axis (the optical axis of the liquid crystal compound) to directions orthogonal to each other, such as in an active shutter type stereoscopic image display device, is exemplified. On the other hand, as various known active retardation layers for switching the magnitude of the retardation, for example, a liquid crystal cell such as a VA (Vertical Alignment) type can be used. By switching the applied voltage, an active retardation layer that switches, for example, between a state where the retardation is zero and a state where the retardation is a half wavelength is exemplified.

[0145] In the present invention, the quarter-wave plate (quarter-wave retardation plate) is a retardation plate having a retardation of approximately a quarter wavelength at any wavelength of visible light. As the quarter-wave plate, for example, a quarter-wave plate having a retardation of 120 nm to 150 nm at a wavelength of 550 nm is preferably exemplified, and a quarter-wave plate having a retardation of 130 nm to 140 nm is more preferably exemplified.

[0146] The pattern retardation layer has a plurality of regions in which the direction of the slow axis and / or the magnitude of the retardation are different. As an example of the pattern retardation layer having different slow axis directions, a quarter-wave plate in which regions are divided in a stripe shape and the slow axis directions are orthogonal to each other in adjacent regions is exemplified. Further, as an example of the pattern retardation layer having different retardations, a pattern retardation layer in which regions are similarly divided into stripe-shaped regions and regions having a retardation of a quarter wavelength and regions having a retardation of three-quarter wavelengths are alternately formed is exemplified. Such a pattern retardation layer may be produced by a known method, such as the method described in JP-A-2012-008170 and the method described in JP-A-2012-032661. Also, commercially available products can be used as the pattern retardation layer.

[0147] In the above examples, the active retardation layer that switches the direction of the slow axis and the pattern retardation layer having a plurality of regions with different slow axis directions were described as representative examples. However, the active retardation layer that switches the magnitude of the retardation and the pattern retardation layer having a plurality of regions with different magnitudes of retardation can also obtain the same effects.

[0148] The active polarizer is a polarizer capable of switching the direction of the transmission axis or the absorption axis. The active polarizer switches the direction of the absorption axis (transmission axis) between two orthogonal directions, for example. Such active polarizers are also available in various known types. As an example, as described in Japanese Patent Application Laid-Open No. 2019-70781, an active polarizer that sandwiches a guest-host type liquid crystal layer having a dichroic dye between a pair of opposing electrode layers and changes the alignment direction of the dichroic dye by applying a voltage is exemplified.

[0149] A pattern polarizer is a polarizer having a plurality of regions with different transmission axis or absorption axis directions. Examples of the pattern polarizer include a pattern retardation layer in which regions are divided in a stripe shape and the directions of the transmission axes (absorption axes) are orthogonal to each other in adjacent regions. Known pattern polarizers such as a patterned polarizer including two or more regions having different absorption axis directions as described in Japanese Patent Application Laid-Open No. 2009-193014 are available in various types.

[0150] In the pattern retardation layer and the pattern polarizer, the pattern of the region is not limited to a stripe shape. Examples of patterns applicable to the pattern retardation layer include not only stripe patterns but also checkerboard patterns.

[0151] As described above, in the aerial image display system of the present invention, when the polarization separation element has an active retardation layer or an active polarizer, the image display device alternately displays the non-floating image R (image of the non-floating image R) and the aerial image V1 (image of the aerial image V1) in a time-division manner. In other words, when the polarization separation element is an active retardation layer or an active polarizer, when the image display device displays the non-floating image R, the polarization separation element switches the direction of the slow axis or the transmission axis (absorption axis) so as to be the optical path of the non-floating image R. Also, when the image display device displays the aerial image V1, the polarization separation element switches the direction of the slow axis or the transmission axis so as to be the optical path of the aerial image V1.

[0152] When the polarization separation element is a patterned retardation layer or a patterned polarizer, the image display device divides (spatially divides) and arranges the non-floating image R (image of the non-floating image R) and the aerial image V1 (image of the aerial image V1) according to the pattern of the polarization separation element, and then displays them. For example, when the pattern of the polarization separation element is stripe-shaped and regions where the slow axis or the transmission axis is orthogonal are alternately arranged, the image display device divides (spatially divides) the image of the non-floating image R and the image of the aerial image V1 into stripes. Then, the image display device displays the divided non-floating image R corresponding to the region where the direction of the slow axis or the transmission axis of the polarization separation element 18 becomes the optical path of the non-floating image R, and the image display device displays the divided aerial image V1 corresponding to the region where the direction of the slow axis or the transmission axis of the polarization separation element 18 becomes the optical path of the aerial image V1.

[0153] Here, in FIGS. 7 to 10, the absorption-type linear polarizer 20 arranged adjacent to the image display device 16 may use the linear polarizer that the image display device has as the absorption-type linear polarizer 20 when the image display device 16 is a device having a linear polarizer, such as an OLED having an antireflection film including a liquid crystal display device and an absorption-type linear polarizer.

[0154] Also, in the examples shown in FIGS. 9 to 12, although the polarization separation element 18 has been described as a case where the absorption-type linear polarizer 28 is a normal linear polarizer and the retardation layer 30 is an active retardation layer or a patterned retardation layer, the retardation layer 30 may be a normal retardation layer and the absorption-type linear polarizer 28 may be an active polarizer or a patterned polarizer.

[0155] Similarly, in this configuration, in the timing or region where the image display device 16 displays the non-floating image R, the polarization separation element 18 transmits only the polarized light passing through the optical path of the non-floating image R and shields the polarized light passing through the optical path of the aerial image V1, thereby showing only the non-floating image R. In the timing or region where the image display device 16 displays the aerial image V1, the polarization separation The element 18 transmits only the polarized light passing through the optical path that forms the aerial image V1, and blocks the polarized light passing through the optical path that forms the non-floating image R, thereby displaying only the aerial image V1. The aerial image display system can display a superimposed image V2 in which the non-floating image R and the aerial image V1 are superimposed by displaying the non-floating image R and the aerial image V1 in a time-division or space-division manner. In a liquid crystal display device, usually, two linear polarizers are provided with a cross Nicol sandwiching a liquid crystal cell. Therefore, as in the examples shown in FIGS. 11 to 12, in a configuration where the polarization separation element 18 is disposed between the image display device 16 and the half mirror 12, when using a liquid crystal display device as the image display device and using an active polarizer or a patterned polarizer, not only the polarizer on the emission side but also the polarizer on the side where the backlight light is incident needs to be changed to an active polarizer or a patterned polarizer. Considering this point, the configuration using an active polarizer and the configuration using a patterned polarizer are more advantageous when using a display device other than a liquid crystal display device as the image display device, for example, when using an OLED as the image display device.

[0156] In the aerial image display system of the present invention, the position where the aerial image V1 is displayed, that is, the floating distance of the aerial image V1 can be adjusted by changing the separation distance between the image display device and the half mirror, the image display device and the reflective polarizer, or the half mirror and the reflective polarizer. Specifically, by increasing any of the above distances, the floating distance of the aerial image V1 can be increased. Also, as in the examples shown in FIGS. 9 to 10, when the polarization separation element and the image display device are separated with a half mirror in between, if a patterned retardation layer or a patterned polarizer is used as the polarization separation element, crosstalk of the image is likely to occur and the image quality is likely to deteriorate.

[0157] In the aerial image display system of the present invention, the position where the aerial image V1 is displayed, that is, the floating distance of the aerial image V1 can be adjusted by changing the separation distance between the image display device and the half mirror, the image display device and the reflective polarizer, or the half mirror and the reflective polarizer. Specifically, by increasing any of the above distances, the floating distance of the aerial image V1 can be increased. In the aerial image display system of the present invention, the position where the aerial image V1 is displayed, that is, the floating distance of the aerial image V1 can be adjusted by changing the separation distance between the image display device and the half mirror, the image display device and the reflective polarizer, or the half mirror and the reflective polarizer. Specifically, by increasing any of the above distances, the floating distance of the aerial image V1 can be increased. In the aerial image display system of the present invention, the position where the aerial image V1 is displayed, that is, the floating distance of the aerial image V1 can be adjusted by changing the separation distance between the image display device and the half mirror, the image display device and the reflective polarizer, or the half mirror and the reflective polarizer. Specifically, by increasing any of the above distances, the floating distance of the aerial image V1 can be increased. In the aerial image display system of the present invention, the position where the aerial image V1 is displayed, that is, the floating distance of the aerial image V1 can be adjusted by changing the separation distance between the image display device and the half mirror, the image display device and the reflective polarizer, or the half mirror and the reflective polarizer. Specifically, by increasing any of the above distances, the floating distance of the aerial image V1 can be increased.

[0158] Also, as in the examples shown in FIGS. 9 to 10, when the polarization separation element and the image display device are separated with a half mirror in between, if a patterned retardation layer or a patterned polarizer is used as the polarization separation element, crosstalk of the image is likely to occur and the image quality is likely to deteriorate. Therefore, in a configuration in which the image display device and the polarization separation element are separated from each other with a half mirror sandwiched therebetween, it is preferable to use an active retardation layer or an active polarizer as the polarization separation element 18.

[0159] [Input system] The aerial image display system of the present invention can be combined with a non-contact touch sensor to form an input system. Specifically, as shown in FIG. 18, an input system 50 includes an aerial image display system 10 and a non-contact touch sensor 52 disposed on the display surface side of the aerial image display system 10, and an aerial image V1 displayed by the aerial image display system 10 is input through the non-contact touch sensor 52. The aerial image V1 is displayed in the space where the force is judged. This allows the user to visually confirm the space where the input is judged by the aerial image V1 when touching the non-contact touch sensor 52 in the air. For example, when the aerial image V1 is displayed, the user U can By touching the space with a finger, a touch operation can be performed by the non-contact touch sensor 52.

[0160] When the aerial image display system is used for such an input system, an aerial image display system that displays only the aerial image V1 and does not display the non-floating image R, as shown in Figs. 7 and 8, is used. Alternatively, as shown in Figs. 9 to 12, aerial image V1 and non-floating image R, which are separate images, may be superimposed. Alternatively, an aerial image display system that displays the same image as a non-floating image and an aerial image, such as the example shown in FIG. 2, may be used.

[0161] As the non-contact touch sensor, an infrared type non-contact touch sensor that irradiates infrared rays and detects the reflected infrared rays to identify an object, a capacitance type non-contact touch sensor, a TOF (Time of flight) sensor, a LIDAR sensor, a non-contact touch sensor that captures a finger or the like with one or a plurality of cameras and detects a touch position, and other known non-contact touch sensors can be used.

[0162] In the example shown in FIG. 18, the non-contact touch sensor 52 is configured to be disposed on the display surface side of the aerial image display system 10. However, the present invention is not limited to this, and depending on the type of the non-contact touch sensor 52, it may be configured to be disposed on the peripheral (bezel) portion of the aerial image display system 10. For example, when using a capacitance type non-contact touch sensor or the like, it is preferable to be configured to be disposed on the display surface side of the aerial image display system 10. On the other hand, when using a TOF sensor, a LIDAR sensor, or the like, it is preferable to be configured to be disposed on the peripheral (bezel) portion of the aerial image display system 10.

[0163] As described above, the aerial image display system and the input system of the present invention have been described in detail. However, the present invention is not limited to the above-described examples, and various improvements and modifications can of course be made without departing from the gist of the present invention.

Industrial Applicability

[0164] It can be suitably used for a car navigation system, an input system, and the like.

Explanation of Reference Numerals

[0165] 10, 10a to 10g Aerial image display system 12 Half mirror 14, 14a to 14c Reflective polarizer 16 Image display device 18 Polarization separation element 20, 26 Absorptive linear polarizer 22, 24 Retardation plate 28 Absorptive linear polarizer 30 - phase difference plate 32 - absorption type circular polarizer 40a - 40c support 42a - 42c reflective polarizer 44a - 44c coating layer 52 - non - contact touch sensor R - non - floating image V1 - aerial image V2 - superimposed image U - user O - object

Claims

1. A half mirror, A reflecting member which is a retroreflective member, An image display device, and has, The reflecting member has a reflective polarizer, and the reflective polarizer constitutes a reflecting surface of the reflecting member, The reflecting member and the half mirror are disposed on the viewing side of the image display device, and in the emission direction of the image light emitted from the image display device, they are arranged in the order of the reflecting member and the half mirror, or in the order of the half mirror and the reflecting member. An aerial image display system.

2. Furthermore, a polarization separation element having a function of separating incident light into polarized lights orthogonal to each other is provided. The aerial image display system according to claim 1.

3. The polarization separation element is an active retardation layer capable of switching the direction of the slow axis or the magnitude of retardation, a pattern retardation layer having a plurality of two types of regions with at least one of the direction of the slow axis and the magnitude of retardation being different, an active polarizer capable of switching the direction of the transmission axis or the absorption axis, and any one of a pattern polarizer having a plurality of two types of regions with different directions of the transmission axis or the absorption axis. The aerial image display system according to claim 2.

4. The reflective polarizer is a reflective circular polarizer, Furthermore, an absorption linear polarizer and a retardation plate are provided, The image display device, the absorption linear polarizer, the retardation plate, the reflecting member, and the half mirror are arranged in this order. The aerial image display system according to claim 1.

5. The reflective polarizer is a reflective circular polarizer, Furthermore, an absorption linear polarizer and a retardation plate are provided, The image display device, the absorption linear polarizer, the retardation plate, the half mirror, and the reflecting member are arranged in this order. The aerial image display system according to claim 1.

6. Furthermore, an absorption circular polarizer is provided on the viewing side. The aerial image display system according to claim 4 or 5.

7. The reflective polarizer is a reflective circular polarizer, Furthermore, an absorption linear polarizer and a retardation plate are provided, The image display device, the absorption linear polarizer, the retardation plate, the reflecting member, the half mirror, and the polarization separation element are arranged in this order. The aerial image display system according to claim 2 or 3.

8. The reflective polarizer is a reflective circular polarizer, The aerial image display system according to claim 2 or 3, wherein the image display device, the polarization separation element, the half mirror, and the reflection member are arranged in this order.

9. The aerial image display system according to claim 8, further comprising an absorption-type circular polarizer on the viewing side of the reflection member.

10. The reflection member has a support, The reflective polarizer is disposed on the surface of the support, A coating layer having the same refractive index as the support is disposed on the surface of the reflective polarizer opposite to the support, The aerial image display system according to any one of claims 1 to 9, wherein the surface of the support opposite to the reflective polarizer and the surface of the coating layer opposite to the reflective polarizer are flat surfaces parallel to each other.

11. The aerial image display system according to any one of claims 1 to 10, wherein the reflective polarizer includes a cholesteric liquid crystal layer.

12. An input system having the aerial image display system according to any one of claims 1 to 11, and a non-contact touch sensor.

Images