Aerial image display device
Patent Information
- Application Number
- JP2021105395
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2021-06-25
- Publication Date
- 2025-04-25
- Estimated Expiration
- 2041-06-25
AI Technical Summary
Existing aerial image display devices face challenges in allowing observers to easily locate the optimal viewing position while preventing others from peeking into the displayed image.
Incorporating a first transmission light control sheet with two states (transmission and restriction) and a sensor to dynamically adjust light transmission based on observer position, ensuring the observer can see the entire image while others are restricted from peeking.
Facilitates easy identification of the viewing position and prevents unauthorized viewing by adjusting light transmission dynamically, enhancing privacy and visibility.
Smart Images
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Abstract
Description
[Technical Field]
[0001] The present application relates to an aerial image display device. [Background technology]
[0002] Aerial image display devices are known that can display images in the air without the need for special glasses or a screen such as fog. For example, aerial image display devices have been disclosed that use a beam splitter and a retroreflective sheet to focus an image displayed on an image display device in space at a position that is plane-symmetrical with respect to the beam splitter, thereby displaying the image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-25776 Summary of the Invention [Problem to be solved by the invention]
[0004] In the aerial image display device disclosed in Patent Document 1, there is an observation position from which the observer viewing the image displayed in the air (hereinafter referred to as the aerial image) can see the entire aerial image. A beam splitter and a retroreflective sheet are present beyond the viewpoint of the aerial image seen by the observer from the observation position. In contrast, at least one of the beam splitter and the retroreflective sheet is not present beyond the viewpoint of the aerial image seen by an observer from outside the observation position, and therefore the aerial image seen by an observer from outside the observation position has its edges cut off. An observer attempting to view the entire aerial image must move around while searching for an observation position.
[0005] An observer trying to view the entire aerial image will move around while searching for the observation position, so the wider the observation position, i.e., the larger the beam splitter and retroreflective sheet, the easier it is to find the position from which the aerial image can be viewed. On the other hand, for the observer operating the aerial image display device at the observation position, a wide observation position will make them vulnerable to peeking, so the narrower the observation position, i.e., the smaller the beam splitter and retroreflective sheet, the better. Therefore, there has been a problem in that it is difficult to realize an aerial image display device that makes it easy to find the position from which the aerial image can be viewed and that is also difficult for others to peeking at.
[0006] The present application has been made to solve the above-mentioned problems, and aims to provide an aerial image display device that makes it easy to see the position from which the aerial image can be seen and makes it difficult for others to peek at it. [Means for solving the problem]
[0007] The aerial image display device disclosed in the present application comprises an image display, a beam splitter that transmits or reflects light, a retroreflective sheet that retroreflects light emitted from the image display and reflected by the beam splitter, a first transmitted light control sheet provided on the surface of the retroreflective sheet and having two states for each region: a transparent state that transmits light and a restricted state that restricts the transmission of light, a sensor that detects the position of an observer, and a controller that switches each region of the first transmitted light control sheet to either the transparent state or the restricted state depending on the output of the sensor, each region of the first transmitted light control sheet being either a transparent region that transmits light that reaches the observer in the transparent state, or a controlled region that is an area of the first transmitted light control sheet excluding the transparent region, and the controller switches the controlled region of the first transmitted light control sheet to the restricted state depending on the output of the sensor when the observer is detected by the sensor, and switches all regions of the first transmitted light control sheet to the transparent state when the observer is not detected by the sensor. [Effects of the Invention]
[0008] The aerial image display device disclosed in the present application comprises an image display, a beam splitter that transmits or reflects light, a retroreflective sheet that retroreflects light emitted from the image display and reflected by the beam splitter, a first transmitted light control sheet provided on the surface of the retroreflective sheet and having two states for each region: a transparent state that transmits light and a restricted state that restricts light transmission, a sensor that detects the position of an observer, and a controller that switches each region of the first transmitted light control sheet to either the transparent state or the restricted state depending on the output of the sensor, each region of the first transmitted light control sheet being either a transparent region that transmits light that reaches the observer in the transparent state, or a controlled region that is an area of the first transmitted light control sheet excluding the transparent regions, and when the sensor detects an observer, the controller switches the controlled region of the first transmitted light control sheet to the restricted state depending on the output of the sensor, and when the sensor does not detect an observer, switches all regions of the first transmitted light control sheet to the transparent state, making it easy to see where the aerial image can be seen and making it difficult for others to spy on the image. [Brief explanation of the drawings]
[0009] [Figure 1] 1 is a schematic diagram of an aerial image display device in accordance with embodiment 1. FIG. [Figure 2] 3 is a diagram showing an example of a first transmitted light control sheet according to the first embodiment. FIG. [Figure 3] 3 is a diagram showing an example of a first transmitted light control sheet according to the first embodiment. FIG. [Figure 4] 3 is a diagram showing an example of a first transmitted light control sheet according to the first embodiment. FIG. [Figure 5] 5A and 5B are diagrams illustrating a method for setting a transmission region in the first transmitted light control sheet according to the first embodiment. [Figure 6] FIG. 10 is a schematic diagram of an aerial image display device in accordance with a second embodiment. DETAILED DESCRIPTION OF THE INVENTION
[0010] Hereinafter, an aerial image display device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the same reference numerals in the various drawings indicate the same or corresponding parts.
[0011] Embodiment 1 FIG. 1 is a schematic diagram of an aerial image display device 1 according to a first embodiment. The aerial image display device 1 includes a housing 2, an image display device 3 disposed within the housing 2, a beam splitter 4 provided at an opening of the housing 2, a retroreflective sheet 5 disposed within the housing 2, a first transmitted light control sheet 6 having two states, a transmitting state and a restricting state, a sensor 7 for detecting the position of an observer 11, and a controller 8 for controlling the first transmitted light control sheet 6 in accordance with the output of the sensor 7. The image display device 3 is, for example, a display. Light emitted from the image display device 3 is incident on the beam splitter 4, a portion of which is reflected, passes through the first transmitted light control sheet 6, and then enters the retroreflective sheet 5. The retroreflective sheet 5 has the property of reflecting the incident light back in the direction of incidence. The retroreflective sheet 5 reflects the light incident from the beam splitter 4 back toward the beam splitter 4. The light reflected from the retroreflective sheet 5 toward the beam splitter 4 passes through the first transmitted light control sheet 6 again, and a portion of the light passes through the beam splitter 4. In this way, the light emitted from image display 3 passes through beam splitter 4 and is imaged outside housing 2, becoming aerial image 10. Observer 11 can observe this aerial image 10.
[0012] Sensor 7 detects the position of the observer, and is, for example, a three-dimensional distance sensor that detects the position of an object in a spatial region. Examples of three-dimensional distance sensors that can be used include a Time of Flight (ToF) sensor and a stereo camera. Sensor 7 may, for example, detect the position of the eyes of observer 11. When multiple people are detected by sensor 7, the person whose eyes are closest to the line connecting the center of aerial image 10 and the center of beam splitter 4 may be determined as observer 11, the person whose eyes are closest to the line connecting the center of aerial image 10 and the center of retroreflective sheeting 5 may be determined as observer 11, or the person whose eyes are closest to aerial image 10. Sensor 7 may also detect the position of the hands or fingers of observer 11, for example. When the hands or fingers of observer 11 are within a predetermined area including aerial image 10, it can be determined that observer 11 is operating aerial image display device 1.
[0013] The first transmitted light control sheet 6 is provided on the surface of the retroreflective sheet 5. Each region has two states: a transmissive state that transmits light and a restricted state that restricts light transmission. The controller 8 controls the two states of each region of the first transmitted light control sheet 6 in response to the output of the sensor 7. In the first transmitted light control sheet 6, the region that transmits light reaching the observer 11 is designated as a transmissive region, and the region other than the transmissive region is designated as a controlled region. For example, when the sensor 7 detects the observer 11, the controller 8 switches the controlled region of the first transmitted light control sheet 6 to the restricted state in response to the output of the sensor 7. The restricted state of the first transmitted light control sheet 6 can be achieved, for example, by blocking light, scattering light, or reducing light transmittance. The first transmitted light control sheet 6 shown in Figure 1 is in the restricted state in the shaded area around the periphery. This allows the observer 11 to view the entire aerial image 10, while others 12a and 12b can only view a portion of the aerial image 10, preventing peeping.
[0014] In the restricted state, the first transmissive light control sheet 6 blocks light, so that other persons 12a and 12b cannot see anything except for a portion of the aerial image 10. In the restricted state, the first transmissive light control sheet 6 scatters light, so that other persons 12a and 12b cannot see the contents of the aerial image 10 in the area other than a portion of the aerial image 10, but can confirm that the aerial image 10 exists. In the restricted state, the first transmissive light control sheet 6 reduces the light transmittance and attenuates the transmitted light, so that the portion of the aerial image 10 visible to other persons 12a and 12b becomes dark, and they are unable to see all of the contents of the aerial image 10.
[0015] Furthermore, since the first transmitted light control sheet 6 is provided on the surface of the retroreflective sheet 5, the aerial image 10 that appears to other person 12a or other person 12b when light transmission is restricted in the first transmitted light control sheet 6 can be made smaller than if the first transmitted light control sheet 6 were provided at another position on the optical path from the image display 3 to the aerial image 10.
[0016] When no viewer is detected by the sensor 7, the entire area of the first transmitted light control sheet 6 is set to a transparent state, thereby transmitting all light traveling from the beam splitter 4 toward the retroreflective sheet 5. This increases the recognizability of the aerial image.
[0017] FIG. 2 is a diagram showing an example of the first transmitted light control sheet 6. The first transmitted light control sheet 61 shown in FIG. 2 has two regions, a transmitted region 61a and a controlled region 61b, with the controlled region 61b indicated by diagonal lines in FIG. 2. The transmitted region 61a is located at a predetermined position, for example, at the center of the first transmitted light control sheet 61. The transmitted region 61a is an area of the aerial image display device 1 shown in FIG. 1 that transmits the light necessary for observer 11 to see the entire aerial image 10, and it always transmits light. When sensor 7 detects observer 11 in a position where the entire aerial image 10 can be seen by the light transmitted through the transmitted region 61a, controller 8 places the controlled region 61b of the first transmitted light control sheet 61 in a restricted state, restricting the transmission of light through controlled region 61b. This allows observer 11 to see the entire aerial image 10, but others 12a and 12b can only see a portion of the aerial image 10, thereby preventing peeping. Note that first transmitted light control sheet 6 may have a shape as shown in controlled area 61b in FIG. 2 , with holes at positions through which light reaching observer 11 passes. In this case, the entire area of first transmitted light control sheet 6 is the controlled area. When sensor 7 does not detect observer 11 in a position where the entire aerial image 10 can be seen by light transmitted through transmissive area 61a, controller 8 sets controlled area 61b of first transmitted light control sheet 61 to the transmissive state. This allows the entire aerial image 10 to be viewed from a wide area when observer 11 is not in a predetermined position. In this way, by setting controlled area 61b of first transmitted light control sheet 61 to an area excluding the area that transmits light that reaches observer 11, peeping can be prevented simply by setting controlled area 61b of first transmitted light control sheet 61 to the restricted state.
[0018] When no observer is detected by sensor 7, controller 8 sets all areas of first transmitted light control sheet 61 to a transparent state. This allows all light traveling from beam splitter 4 toward retroreflective sheet 5 to be transmitted through first transmitted light control sheet 61, thereby increasing the recognizability of the presence of aerial image 10.
[0019] FIG. 3 is a diagram showing another example of the first transmitted light control sheet 6. The first transmitted light control sheet 62 shown in the upper diagram of FIG. 3 is formed by tiling transmitted light control elements 621, each of which has two states: a transmitting state in which light is transmitted and a restricting state in which light transmission is restricted. When the sensor 7 detects the position of the observer 11, the controller 8 sets two regions, a transmitting region 62a and a controlled region 62b, on the first transmitted light control sheet 62 based on the position information of the observer 11 detected by the sensor 7. The transmitting region 62a is a region of the aerial image display device 1 shown in FIG. 1 that transmits light that reaches the observer 11, and the controlled region 62b is a region of the first transmitted light control sheet 62 excluding the transmitting region 62a. The controller 8 sets the transmitted light control elements 621 in the transmitting region 62a to the transmitting state and the transmitted light control elements 621 in the controlled region 62b to the restricting state.
[0020] The middle diagram in FIG. 3 shows an example in which the transmissive region 62a is set in the center of the first transmitted light control sheet 62. In the middle diagram in FIG. 3, the blank region in the center of the first transmitted light control sheet 62 is the transmissive region 62a, and the shaded region is the controlled region 62b. The controller 8 sets the transmitted light control elements 621 in the transmissive region 62a to the transmitting state and the transmitted light control elements 621 in the controlled region 62b to the restricting state. Therefore, in the first transmitted light control sheet 62 shown in the middle diagram in FIG. 3, the blank transmitted light control elements 621 are in the transmitting state and the shaded transmitted light control elements 621 are in the restricting state. The bottom diagram in FIG. 3 shows an example in which the transmissive region 62a is set in the upper left. As shown in the middle and bottom diagrams of Figure 3, the controller 8 can move the transparent area 62a of the first transmitted light control sheet 62 according to the position of the observer 11 detected by the sensor 7, so that the observer 11 can always see the entire aerial image 10 even if the observer 11 moves.
[0021] Note that sensor 7 detects the position of the hand or finger of observer 11, and further sensor 7 detects the position of the eye of observer 11, and controller 8 determines that observer 11 is operating aerial image display device 1 when the hand or finger of observer 11 is in a predetermined area including aerial image 10, and sets an area that transmits light that reaches observer 11 when operation starts as the transparent area, and fixes the position of the transparent area when it is determined that operation by observer 11 is continuing.
[0022] When no viewer is detected by sensor 7, controller 8 sets all transmitted light control elements 621 of first transmitted light control sheet 62 to the transmitting state, thereby setting all areas of first transmitted light control sheet 62 to the transmitting state. This allows all light traveling from beam splitter 4 toward retroreflective sheet 5 to be transmitted through first transmitted light control sheet 62, making it easier to recognize that aerial image 10 is present.
[0023] FIG. 4 is a diagram showing another example of the first transmitted light control sheet 6. The middle diagram in FIG. 4 shows a first sheet layer 64. The first sheet layer 64 is made up of strip-shaped first strip sheets 641, which have two states: a transmissive state in which light transmits and a restrictive state in which light transmission is restricted, arranged with their long sides in contact with each other. The bottom diagram in FIG. 4 shows a second sheet layer 65. The second sheet layer 65 is made up of strip-shaped second strip sheets 651, which have two states: a transmissive state in which light transmits and a restrictive state in which light transmission is restricted, arranged with their long sides in contact with each other. The first sheet layer 64 and the second sheet layer 65 stacked together form the first transmitted light control sheet 63 shown in the top diagram in FIG. 4. In the first transmitted light control sheet 63 shown in Figure 4, the direction along the long side of the first strip sheet 641 of the first sheet layer 64 and the direction along the long side of the second strip sheet 651 of the second sheet layer 65 are stacked perpendicularly to each other, but it is sufficient that the direction along the long side of the first strip sheet 641 of the first sheet layer 64 and the direction along the long side of the second strip sheet 651 of the second sheet layer 65 are different directions.
[0024] FIG. 5 is a diagram illustrating a method for setting a transmission region in first transmitted light control sheet 63 shown in FIG. 4. When sensor 7 detects observer 11, controller 8 sets two regions, a first transmission region 64a and a first controlled region 64b, in first sheet layer 64 as shown in the middle diagram of FIG. 5 based on the position information of observer 11 detected by sensor 7. In the middle diagram of FIG. 5, the blank region in the center of first sheet layer 64 is first transmission region 64a, and the shaded region is first controlled region 64b. First transmission region 64a is a region that transmits light that reaches observer 11 in aerial image display device 1 shown in FIG. 1, and first controlled region 64b is a region of first sheet layer 64 excluding first transmission region 64a. Controller 8 sets first strip-shaped sheet 641 in first transmission region 64a to a transmission state and first strip-shaped sheet 641 in first controlled region 64b to a restricted state.
[0025] Similarly, when sensor 7 detects observer 11, controller 8 sets two regions, second transmissive region 65a and second controlled region 65b, on second sheet layer 65 as shown in the lower diagram of FIG. 5 based on the position information of observer 11 detected by sensor 7. In the lower diagram of FIG. 5, the blank region in the center of second sheet layer 65 is second transmissive region 65a, and the shaded region is second controlled region 65b. Second transmissive region 65a is a region that transmits light reaching observer 11 in aerial image display device 1 shown in FIG. 1, and second controlled region 65b is a region on second sheet layer 65 excluding second transmissive region 65a. Controller 8 sets second strip-shaped sheet 651 in second transmissive region 65a to the transmissive state, and second strip-shaped sheet 651 in second controlled region 65b to the restricted state.
[0026] As a result, as shown in the upper diagram of Figure 5, a transparent region 63a and a controlled region 63b are defined in first transmitted light control sheet 63, which is made up of first sheet layer 64 and second sheet layer 65 superimposed on top of each other. Controller 8 can move transparent region 63a of first transmitted light control sheet 63 in accordance with the position of observer 11 detected by sensor 7, allowing observer 11 to always see the entire aerial image 10 even when observer 11 moves. Furthermore, because the short sides of all first strip-shaped sheets 641 and second strip-shaped sheets 651 are located at the end of first transmitted light control sheet 63, connection between controller 8 and first strip-shaped sheet 641 and connection between controller 8 and second strip-shaped sheet 651 are easy.
[0027] Note that sensor 7 detects the position of the hand or finger of observer 11, and further sensor 7 detects the position of the eye of observer 11, and controller 8 determines that observer 11 is operating aerial image display device 1 when the hand or finger of observer 11 is in a predetermined area including aerial image 10, and sets an area that transmits light that reaches observer 11 when operation starts as the transparent area, and fixes the position of the transparent area when it is determined that operation by observer 11 is continuing.
[0028] When sensor 7 does not detect an observer within a predetermined area, controller 8 sets all areas of first sheet layer 64 and second sheet layer 65 to a transparent state. This allows all light traveling from beam splitter 4 toward retroreflective sheet 5 to be transmitted through first transmitted light control sheet 63, thereby increasing the recognizability of the presence of aerial image 10.
[0029] As described above, the aerial image display device 1 according to the first embodiment comprises the image display 3, the beam splitter 4 that transmits or reflects light, the retroreflective sheet 5 that retroreflects light emitted from the image display 3 and reflected by the beam splitter 4, the first transmitted light control sheet 6 that is provided on the surface of the retroreflective sheet 5 and has two states for each region: a transmission state that transmits light and a restriction state that restricts the transmission of light, the sensor 7 that detects the position of the observer 11, and the controller 8 that switches each region of the first transmitted light control sheet 6 to either the transmission state or the restriction state according to the output of the sensor 7. Each region of the first transmitted light control sheet 6 is either a transmissive region that transmits light that reaches the observer in a transmissive state, or a controlled region that is the region of the first transmitted light control sheet 6 excluding the transmissive region, and when an observer 11 is detected by a sensor 7, a controller 8 puts the controlled region of the first transmitted light control sheet 6 into a restricted state in accordance with the output of the sensor 7, and when an observer 11 is not detected by the sensor 7, puts all regions of the first transmitted light control sheet 6 into a transmissive state, making it easy to see the position where the aerial image can be seen and making it difficult for others to peek at it.
[0030] Embodiment 2 Fig. 6 is a schematic diagram of an aerial image display device 1a according to embodiment 2. Comparing the aerial image display device 1a according to embodiment 2 shown in Fig. 6 with the aerial image display device 1 according to embodiment 1 shown in Fig. 1, a second transmitted light control sheet 9 is provided instead of the first transmitted light control sheet 6, and controller 8 has become controller 8a. Other configurations of the aerial image display device 1a according to embodiment 2 are the same as those of the aerial image display device 1 according to embodiment 1.
[0031] The second transmitted light control sheet 9 has two states: an open state in which it allows light to pass through, and a limiting state in which it limits the transmission of light. The second transmitted light control sheet 9 is provided on the surface of the beam splitter 4 on the observer 11 side, i.e., the surface of the beam splitter 4 opposite to the surface facing the retroreflective sheet 5. If the beam splitter 4 is provided inside a transparent window provided in the housing 2, the second transmitted light control sheet 9 may be provided on the observer 11 side of the beam splitter 4, with the housing 2 in between. The controller 8a controls the second transmitted light control sheet 9 in accordance with the output of the sensor 7.
[0032] The structure and operation of the second transmitted light control sheet 9 are the same as those of the first transmitted light control sheet 6 according to embodiment 1, for example, those of any of the first transmitted light control sheets 6 shown in Figures 2 to 5, and the control of the second transmitted light control sheet 9 by the controller 8a is the same as the control of the first transmitted light control sheet 6 by the controller 8 according to embodiment 1. The difference is that while the first transmitted light control sheet 6 is provided on the surface of the retroreflective sheet 5, the second transmitted light control sheet 9 is provided on the surface of the beam splitter 4 on the observer 11 side.
[0033] In the aerial image display device 1a according to the second embodiment, as with the aerial image display device 1 according to the first embodiment, the position from which the aerial image can be viewed is easy to see, making it difficult for others to peek at the aerial image. In the aerial image display device 1 according to the first embodiment, when observer 11 views aerial image 10, they see light that has been transmitted twice through the transmissive region of first transmitted light control sheet 6. On the other hand, in the aerial image display device 1a according to the second embodiment, when observer 11 views aerial image 10, they see light that has been transmitted once through the transmissive region of second transmitted light control sheet 9. Therefore, if the amount of light is reduced when passing through the transmissive region, a brighter aerial image 10 can be viewed in the aerial image display device 1a according to the second embodiment compared to the aerial image display device 1 according to the first embodiment.
[0034] Although the present application describes various exemplary embodiments, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are conceivable within the scope of the technology disclosed in this application, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with a component of another embodiment. [Explanation of symbols]
[0035] 1, 1a Aerial image display device, 2 Housing, 3 Image display, 4 Beam splitter, 5 Retroreflective sheet, 6 First transmitted light control sheet, 7 Sensor, 8, 8a Controller, 9 Second transmitted light control sheet, 10 Aerial image, 11 Observer, 12a, 12b Other person, 61 First transmitted light control sheet, 61a Transmitting area, 61b Controlled area, 62 First transmitted light control sheet, 62a Transmitting area, 62b Controlled area, 63 First transmitted light control sheet, 63a Transmitting area, 63b Controlled area, 64 First sheet layer, 64a First transmitting area, 64b First controlled area, 65 Second sheet layer, 65a Second transmitting area, 65b Second controlled area, 621 Transmitted light control element, 641 First belt-shaped sheet, 651 Second belt-shaped sheet.
Claims
1. A video display; a beam splitter that transmits or reflects light; a retroreflective sheet that retroreflects light emitted from the image display and reflected by the beam splitter; a first transmitted light control sheet provided on the surface of the retroreflective sheet, the first transmitted light control sheet having two states for each region: a transmitting state in which light is transmitted and a limiting state in which light transmission is limited; a sensor for detecting the position of an observer; a controller that switches each region of the first transmitted light control sheet to either the transmitting state or the restricting state in response to an output of the sensor; each region of the first transmitted light control sheet is either a transmissive region that transmits light reaching the viewer in the transmitted state or a controlled region that is a region of the first transmitted light control sheet excluding the transmissive region, The controller When the viewer is detected by the sensor, the controlled area of the first transmitted light control sheet is brought into the restricted state in accordance with an output of the sensor; an aerial image display device, characterized in that when the viewer is not detected by the sensor, all areas of the first transmitted light control sheet are in the transmissive state;
2. the transmission region is located at a predetermined position on the first transmission light control sheet; The controller 2. The aerial image display device according to claim 1, wherein when the observer is detected by the sensor in a position where the entire aerial image can be seen by light transmitted through the transparent area, the controlled area of the first transmitted light control sheet is put into the restricted state.
3. the first transmitted light control sheet is a tile-like arrangement of transmitted light control elements having two states, the transmitting state and the restricting state, The controller Based on the position information of the viewer detected by the sensor, The aerial image display device described in claim 1, characterized in that the area of the first transmitted light control sheet that transmits light reaching the observer is set to the transmitted area, the area of the first transmitted light control sheet excluding the transmitted area is set to the controlled area, the transmitted light control elements in the transmitted area are set to the transmitted state, and the transmitted light control elements in the controlled area are set to the restricted state.
4. The first transmitted light control sheet is a first sheet layer in which first belt-shaped sheets, each having two states, a transmission state in which light is transmitted and a restriction state in which light transmission is restricted, are arranged with their long sides in contact with each other; a second sheet layer in which second strip-shaped sheets having two states, the transmitting state in which light is transmitted and the restricting state in which light transmission is restricted, are arranged with their long sides in contact with each other; The first belt-shaped sheet and the second belt-shaped sheet are stacked in different directions along the long sides thereof, The controller Based on the position information of the viewer detected by the sensor, a region of the first sheet layer that transmits light reaching the viewer is set as a first transmission region, a region of the first sheet layer excluding the first transmission region is set as a first controlled region, the first belt-shaped sheet in the first transmission region is set to the transmission state, and the first belt-shaped sheet in the first controlled region is set to the restricted state; The aerial image display device described in claim 1, characterized in that the area of the second sheet layer that transmits light reaching the observer is set to a second transparent area, the area of the second sheet layer excluding the second transparent area is set to a second controlled area, the second strip sheet in the second transparent area is set to the transparent state, and the second strip sheet in the second controlled area is set to the restricted state.
5. The aerial image display device according to any one of claims 1 to 4, wherein the first transmitted light control sheet blocks transmitted light in the restricted state.
6. The aerial image display device according to any one of claims 1 to 4, wherein the first transmitted light control sheet scatters light that is transmitted in the restricted state.
7. The aerial image display device according to any one of claims 1 to 4, wherein the first transmitted light control sheet attenuates transmitted light in the restricted state.
8. A video display; a beam splitter that transmits or reflects light; a retroreflective sheet that retroreflects light emitted from the image display and reflected by the beam splitter; a second transmitted light control sheet provided on a surface of the beam splitter opposite to the surface facing the retroreflective sheet, the second transmitted light control sheet having two states for each region: a transmitting state in which light is transmitted and a limiting state in which light transmission is limited; a sensor for detecting the position of an observer; a controller that switches each region of the second transmitted light control sheet to either the transmitting state or the restricting state in response to an output of the sensor; each region of the second transmitted light control sheet is either a transmission region that transmits light reaching the viewer in the transmission state or a controlled region that is a region of the second transmitted light control sheet excluding the transmission region, The controller When the viewer is detected by the sensor, the controlled area of the second transmitted light control sheet is brought into the restricted state in accordance with an output of the sensor; an aerial image display device, characterized in that when the observer is not detected by the sensor, the controlled area of the second transmitted light control sheet is set to the transmissive state;