JP7630375B2 - Aerial image display device - Google Patents

Description

This application relates to an aerial image display device.

Aerial image display devices are known that do not require special glasses and can display images in the air without using a screen such as fog. For example, an aerial image display device has been disclosed that uses 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).

JP 2009-25776 A

In the aerial image display device shown in Patent Document 1, there is an observation position where 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 at 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 at the viewpoint of the aerial image seen by an observer from outside the observation position, so the aerial image seen by an observer from outside the observation position has its edges cut off. An observer who wants to see the entire aerial image must move around while searching for an observation position.

An observer who wishes to view the entire aerial image will move around while searching for an observation position, so the wider the observation position, i.e., the larger the beam splitter and retroreflective sheet, the easier it is to see where the aerial image can be seen. On the other hand, for an observer operating the aerial image display device at an observation position, a wide observation position means that others will be peeking at them, so the narrower the observation position, i.e., the smaller the beam splitter and retroreflective sheet, the better. This has led to the problem that it is difficult to realize an aerial image display device that is easy to see where the aerial image can be seen and that is also difficult for others to peek at.

This 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 where the aerial image is visible and makes it difficult for others to peek at it.

The aerial image display device disclosed in this application is characterized by comprising 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 mirror that reflects light that travels from the beam splitter to the outside of the retroreflective sheet and directs it to the retroreflective sheet, a transmitted light control sheet that is provided on the surface of the mirror and has two states, a transmission state that transmits light and a restriction state that restricts the transmission of light, a sensor that detects the position of the observer, and a controller that switches the transmitted light control sheet to either the transmission state or the restriction state depending on the output of the sensor.

The aerial image display device disclosed in this application includes a mirror that reflects light that is directed from the beam splitter toward the outside of the retroreflective sheet and directs it to the retroreflective sheet, a transmitted light control sheet that is provided on the surface of the mirror and has two states, a transparent state that transmits light and a restricted state that restricts the transmission of light, a sensor that detects the position of the observer, and a controller that switches the transmitted light control sheet to either the transparent state or the restricted state depending on the output of the sensor, making it easy to see where the aerial image is visible and making it difficult for others to peek at it.

1 is a schematic diagram of an aerial image display device according to embodiment 1. FIG. 11 is a schematic diagram of an aerial image display device according to a second embodiment.

The following describes in detail an aerial image display device according to an embodiment of the present invention with reference to the drawings. Note that the same reference numerals in each drawing indicate the same or corresponding parts.

Embodiment 1.
Fig. 1 is a schematic diagram of an aerial image display device 1 according to embodiment 1. The upper diagram in Fig. 1 is a diagram of the aerial image display device 1 as viewed from the side, and the lower diagram in Fig. 1 is a diagram of the aerial image display device 1 as viewed from above. In Fig. 1, the x-axis is the left-right direction as viewed by an observer 11, the y-axis is the depth direction as viewed by the observer 11, and the z-axis is the up-down direction as viewed by the observer 11. The x-axis, y-axis, and z-axis are each perpendicular to each other.

The aerial image display device 1 includes a housing 2, an image display 3 arranged inside the housing 2, a beam splitter 4 provided at the opening of the housing 2, a retroreflective sheet 5 arranged inside the housing 2, a mirror 6 arranged inside the housing 2, a transmitted light control sheet 7 installed on the surface of the mirror 6 and having two states, a transmission state and a restricted state, a sensor 8 that detects the position of the observer 11, and a controller 9 that controls the transmitted light control sheet 7 according to the output of the sensor 8. The sensor 8 and the controller 9 are not shown in the lower diagram of FIG. 1. For example, a liquid crystal display, an organic EL display, or a display in which LED elements are arranged can be used as the image display 3. For example, a half mirror or a reflective polarizing plate can be used as the beam splitter 4. For example, a glass bead type sheet in which spherical transparent glass beads are arranged, or a microprism type sheet in which transparent triangular pyramids are arranged can be used as the retroreflective sheet 5. The light emitted from the image display 3 enters the beam splitter 4, and a part of it is reflected and enters the retroreflective sheet 5. The retroreflective sheet 5 has the property of reflecting incident light in the direction of incidence. The retroreflective sheet 5 reflects the light incident from the beam splitter 4 toward the beam splitter 4. A portion of the light reflected from the retroreflective sheet 5 toward the beam splitter 4 passes through the beam splitter 4. In this way, the light emitted from the image display 3 passes through the beam splitter 4 and is imaged outside the housing 2, becoming an aerial image 10. An observer 11 can observe this aerial image 10.

As seen by the observer 11, each of the mirrors 6, one on each side of the retroreflective sheet 5, is fully reflective and flat, and reflects the light traveling from the beam splitter 4 to the outside of the retroreflective sheet 5 and guides it to the retroreflective sheet 5. In the aerial image display device 1 shown in Figure 1, the left-right direction as seen by the observer 11 is the direction along a line that intersects at right angles with both a line that intersects at right angles with the plane that is the display surface of the image display 3 and a line that intersects at right angles with the plane that is the reflective surface of the beam splitter 4, i.e., the direction along the x-axis.

In the lower diagram of FIG. 1, an example of light traveling from the beam splitter 4 toward the outside of the retroreflective sheet 5 is shown by an arrow. In the lower diagram of FIG. 1, light emitted from the image display 3 and reflected by the beam splitter 4 travels toward the outside of the retroreflective sheet 5. Here, we will explain the light traveling from the beam splitter 4 toward the outside of the retroreflective sheet 5 when the transmitted light control sheet 7 is in a transmitting state. The light that is emitted from the image display 3, reflected by the beam splitter 4, and traveling from the beam splitter 4 toward the outside of the retroreflective sheet 5 passes through the transmitted light control sheet 7 and is reflected by the mirror 6. The light reflected by the mirror 6 passes through the transmitted light control sheet 7 again and is guided to the retroreflective sheet 5. The light that passes through the transmitted light control sheet 7 and is guided to the retroreflective sheet 5 is reflected by the retroreflective sheet 5 in the direction of the mirror 6. The light reflected in the direction of the mirror 6 passes through the transmitted light control sheet 7, is reflected by the mirror 6, passes through the transmitted light control sheet 7 again, and part of it passes through the beam splitter 4 to become part of the aerial image 10.

In the lower diagram of FIG. 1, the observer 11 can see the retroreflective sheet 5 reflected by the mirror 6 as a virtual retroreflective sheet 12. In the aerial image display device 1 according to embodiment 1, by installing the mirror 6 around each of the left and right ends of the retroreflective sheet 5 as seen by the observer 11, it is possible to widen the horizontal viewing angle as seen by the observer 11 by the same amount as when the retroreflective sheet 5 is expanded to the position of the virtual retroreflective sheet 12. By widening the horizontal viewing angle as seen by the observer 11, it becomes easier for the observer 11 approaching the aerial image display device 1 from the left or right to see the entire aerial image 10.

In addition, because the end of the mirror 6 comes into contact with the surface of the retroreflective sheet 5, even if some of the light seen as the aerial image 10 is reflected by the mirror 6 and some is not, the aerial image 10 can be viewed as a continuous image.

In the aerial image display device 1 shown in FIG. 1, the mirror 6 is a flat surface, and the flat reflective surface of the mirror 6 is perpendicular to the flat reflective surface of the beam splitter 4 and the flat surface of the retroreflective sheet 5. However, any surface can be used as long as it reflects the light from the beam splitter 4 toward the outside of the retroreflective sheet 5 and guides it to the retroreflective sheet 5. However, since the retroreflective sheet 5 has a lower retroreflective performance as the angle of incidence of light increases, by making the mirror 6 a flat surface and making the flat reflective surface of the mirror 6 perpendicular to the flat reflective surface of the beam splitter 4 and the flat surface of the retroreflective sheet 5, it is possible to realize an aerial image display device 1 with a large viewing angle in a small housing while maintaining the retroreflective performance of the retroreflective sheet 5. In addition, by making the plane that is the reflective surface of the mirror 6 perpendicular to the plane that is the reflective surface of the beam splitter 4 and the plane that is the surface of the retroreflective sheet 5, and by locating the mirror 6 in a position that reflects the light that travels from the beam splitter 4 to the outside of the retroreflective sheet 5 and directs it to the retroreflective sheet 5, the mirror 6 is positioned to the left and right as seen by the observer 11, widening the viewing angle in the left and right directions as seen by the observer 11, making it easier for the observer 11 approaching from the left and right directions of the aerial image display device 1 to see the entire aerial image 10.

The sensor 8 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. As the three-dimensional distance sensor, for example, a ToF sensor (Time of Flight Sensor), a stereo camera, or the like can be used. The sensor 8 may detect, for example, the eye position of the observer 11. When multiple people are detected by the sensor 8, for example, the person whose eye position is closest to the line connecting the center of the aerial image 10 and the center of the beam splitter 4 may be the observer 11, the person whose eye position is closest to the line connecting the center of the aerial image 10 and the center of the retroreflective sheet 5 may be the observer 11, or the person whose eye position is closest to the aerial image 10 may be the observer 11. The sensor 8 may also detect, for example, the position of the hand or finger of the observer 11. If the hand or finger of the observer 11 is in a predetermined area including the aerial image 10, it can be determined that the observer 11 is operating the aerial image display device 1.

The transmitted light control sheet 7 is provided on the surface of the mirror 6 and has two states: a transmitting state in which light is transmitted, and a restricting state in which light transmission is restricted. The controller 9 switches the transmitted light control sheet 7 between the transmitting state and the restricting state according to the output of the sensor 8. For example, when the sensor 8 detects an observer 11 in a predetermined area, the controller 9 switches the transmitted light control sheet 7 to the restricting state and restricts the transmission of light from the transmitted light control sheet 7. For example, when the eyes of the observer 11 are detected in a position where the entire aerial image 10 can be observed only from the light directly directed from the beam splitter 4 to the retroreflective sheet 5, the controller 9 switches the transmitted light control sheet 7 to the restricting state and restricts the transmission of light from the transmitted light control sheet 7. As a result, the observer 11 can see the entire aerial image 10, but the light reflected by the mirror 6 is restricted by the transmitted light control sheet 7, narrowing the viewing angle of the aerial image display device 1, and people other than the observer 11 can only see a part of the aerial image 10, thereby suppressing peeking by others.

In addition, by blocking the transmitted light in the restricted state of the transmitted light control sheet 7, others cannot see the aerial image 10 at all except for a part of it. In addition, by scattering the transmitted light in the restricted state of the transmitted light control sheet 7, others cannot see the contents of the aerial image 10 in the area other than a part of the aerial image 10, but they can confirm that the aerial image 10 exists. When the sensor 8 does not detect an observer within the predetermined area, the controller 9 sets the transmitted light control sheet 7 to a transmitting state and transmits the light reflected by the mirror 6. This increases the awareness that an aerial image exists.

For example, when the controller 9 detects the observer's hand or finger within a predetermined area including the aerial image 10, the controller 9 may set the transmitted light control sheet 7 to a restricted state. As a result, for example, the observer 11 who is operating a button displayed on the aerial image 10 to input a PIN number can see the entire aerial image 10, but the transmitted light control sheet 7 restricts the transmission of light, narrowing the viewing angle of the aerial image display device 1, so that others other than the observer 11 can see only a part of the aerial image 10, thereby suppressing peeking by others. When the sensor 8 does not detect the observer's hand or finger within the predetermined area, the controller 9 sets the transmitted light control sheet 7 to a transparent state, thereby increasing the recognition that there is an aerial image. Alternatively, the controller 9 may determine the operation by the observer 11 based on the content displayed on the aerial image 10 and the position of the observer's hand or finger detected by the sensor 8, and set the transmitted light control sheet 7 to a transparent state when the operation by the observer 11 is completed, or when a predetermined time has elapsed since the operation by the observer 11 was completed. Additionally, the controller 9 may set the transmitted light control sheet 7 to a transparent state when the display of predetermined content, such as a PIN entry operation menu, on the aerial image 10 is completed.

As described above, the aerial image display device 1 according to embodiment 1 includes an image display 3, a beam splitter 4 that transmits or reflects light, a retroreflective sheet 5 that retroreflects light emitted from the image display 3 and reflected by the beam splitter 4, a mirror 6 that reflects light that travels from the beam splitter 4 to the outside of the retroreflective sheet 5 and directs it to the retroreflective sheet 5, a transmitted light control sheet 7 that is provided on the surface of the mirror 6 and has two states, a transmitting state that transmits light and a restricting state that restricts the transmission of light, a sensor 8 that detects the position of the observer 11, and a controller 9 that switches the transmitted light control sheet 7 to either the transmitting state or the restricting state depending on the output of the sensor 8. This makes it easy to see where the aerial image is visible, and makes it difficult for others to peek at it.

Embodiment 2.
Fig. 2 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. 2 with the aerial image display device 1 according to embodiment 1 shown in Fig. 1, the mirror 6 has become a mirror 6a, and the transmitted light control sheet 7 has become a transmitted light control sheet 7a. The 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.

The mirrors 6a, one on each side as seen by the observer 11, are in contact with the retroreflective sheet 5 and also with the beam splitter 4. Installing them in this manner provides the same effect as the aerial image display device 1 according to embodiment 1, while also making the virtual retroreflective sheet 12a in the housing 2 the largest possible, thereby widening the viewing angle to the greatest extent. Note that it does not matter whether the end of the mirror 6a is in contact with the beam splitter 4, or whether the ends of the beam splitter 4 on the left and right sides as seen by the observer 11 are in contact with the mirrors 6a.

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 modifications not exemplified are assumed within the scope of the technology disclosed in the present application, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.

1, 1a Aerial image display device, 2 Housing, 3 Image display, 4 Beam splitter, 5 Retroreflective sheet, 6, 6a Mirror, 7, 7a Transmitted light control sheet, 8 Sensor, 9 Controller, 10 Aerial image, 11 Observer, 12, 12a Virtual retroreflective sheet.

Claims (8)

A video display device;
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 mirror that reflects light emitted from the beam splitter toward the outside of the retroreflective sheet and guides the light to the retroreflective sheet;
a transmitted light control sheet provided on a surface of the mirror and having two states, 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;
and a controller that switches the transmitted light control sheet to either the transmitting state or the restricting state depending on the output of the sensor. When the sensor detects the viewer within a predetermined area, the controller places the transmitted light control sheet in the limiting state;
2. The aerial image display device according to claim 1, wherein the controller puts the transmitted light control sheet into the transmitting state when the sensor does not detect the observer within a predetermined area. The controller includes:
When the sensor detects the hand or finger of the viewer within a predetermined area, the transmitted light control sheet is put into the restricted state;
determining an operation by the observer based on the content displayed in the aerial image and the position of the observer's hand or finger detected by the sensor;
The aerial image display device according to claim 1, characterized in that the transmitted light control sheet is put into the transparent state when the operation by the observer is completed, when a predetermined time has elapsed since the operation by the observer was completed, or when the display of predetermined content on the aerial image is completed. The aerial image display device according to any one of claims 1 to 3, wherein the transmitted light control sheet blocks light in the restricted state. The aerial image display device according to claim 1 , wherein the transmitted light control sheet scatters light in the restricted state. An aerial image display device according to any one of claims 1 to 5, characterized in that the plane that is the reflective surface of the mirror is perpendicular to the plane that is the reflective surface of the beam splitter and the plane that is the surface of the retroreflective sheet. The aerial image display device according to any one of claims 1 to 6, characterized in that the mirror is in contact with the retroreflective sheet. The aerial image display device according to claim 7, characterized in that the mirror is in contact with the beam splitter.

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