JP2023024054A - Image display device and image display method - Google Patents

Abstract

To provide an image display device and image display method which allow a viewer to easily recognize the display contents even when an image that changes over the time is formed in the air.SOLUTION: An image display device comprises: a first image projection unit (20) which irradiates a first image; a second image projection unit (40) which irradiates a second image; a first image formation optical unit (30) which forms the first image at a first distance d1; a second image formation optical unit (50) which forms the second image at a second distance d2 different from the first distance d1; and an image control unit which controls the first image projection unit (20) and the second image projection unit (40). The image control unit includes an image delay section (60) that delays the display timing of the first image by the first delay time Δt1 to use it as the second image.SELECTED DRAWING: Figure 1

Description

The present invention relates to an image display device and an image display method, and more particularly to an image display device and an image display method for forming and displaying a plurality of images at different spatial positions.

2. Description of the Related Art Conventionally, as a device for displaying various types of information in a vehicle, a dashboard that displays icons by lighting has been used. In addition, as the amount of information to be displayed increases, it has been proposed to embed an image display device in the instrument panel or to configure the entire instrument panel with an image display device.

However, since the instrument panel is located below the windshield of the vehicle, it is not preferable for the driver to view the information displayed on the instrument panel by moving the line of sight downward during driving. Accordingly, a head-up display (hereinafter referred to as HUD) has also been proposed, which projects an image onto the windshield so that the driver can read information when looking ahead of the vehicle. A wearable HUD that is worn on the body has also been proposed as an image display device that projects light using a small optical device.

These HUDs have been proposed that reflect light emitted from a light source with a combiner, project the light onto the viewer's eyeball, and display an image superimposed on the background of the combiner. There has also been proposed a system in which light from a light source is imaged in the air by an imaging optical system, and a virtual image or a real image formed in the air is superimposed on a background and displayed. HUD devices have also been proposed that display images with a sense of depth by forming a plurality of images at different positions from viewpoints (see Patent Documents 1 to 3, for example).

JP 2021-047234 A JP 2021-089396 A JP 2021-096284 A

Such a HUD that forms a plurality of images in the air displays the plurality of images at different positions from the viewpoint, and therefore has the advantage that the viewer can easily separate and recognize the different images. However, since multiple images are formed on the same line of sight, the amount of information received by the viewer tends to be large. can become difficult to do.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and provides an image display apparatus and an image display method that enable a viewer to easily recognize display contents even when an image that changes with time is formed in the air. intended to provide

In order to solve the above problems, the image display device of the present invention includes a first image projection unit that projects a first image, a second image projection unit that projects a second image, and a projection of the first image by a first distance. a first imaging optical section that forms an image at d1; a second imaging optical section that forms an image of the second image at a second distance d2 different from the first distance d1; the first image projection section; a control unit for controlling a second image projection unit, wherein the control unit comprises an image delay unit for delaying the display timing of the first image by a first delay time Δt1 and using it as the second image. characterized by

In such an image display device of the present invention, after the first image is formed at the first distance d1 and the first delay time Δt1 has elapsed, the same content as the first image is used as the second image at the second distance d2. to form an image. As a result, the transition of the display contents over time can be visually recognized as if the position of the afterimage changes, and even when an image that changes over time is formed in the air, the viewer can easily recognize the display contents. can.

Further, in one aspect of the present invention, the control unit makes the brightness b2 of the second image lower than the brightness b1 of the first image.

Further, in one aspect of the present invention, a third image projection unit that projects a third image, and a third image projection unit that forms the third image at a third distance d3 different from the first distance d1 and the second distance d2. 3 imaging optical units, and the image delay unit delays the display timing of the third image by a second delay time Δt2 and uses it as the first image.

Further, in one aspect of the present invention, the control unit makes the brightness b3 of the third image lower than the brightness b1 of the first image.

In one aspect of the present invention, when the difference between the first distance d1 and the second distance d2 is Δd1 and the difference between the first distance d1 and the third distance d3 is Δd2, Δd1:Δd2=Δt1 : Δt2.

In one aspect of the present invention, the difference between the brightness b1 of the first image A1 and the brightness b2 of the second image A2 is Δb1, and the difference between the brightness b1 and the brightness b3 of the third image A3 is Δb2. , Δd1:Δd2=Δb2:Δb1.

Further, in one aspect of the present invention, the first image and the second image are superimposed and displayed on the same line-of-sight direction at the same viewpoint position.

Further, in one aspect of the present invention, the first image and the second image are displayed in different line-of-sight directions at the same viewpoint position.

Further, the image display method of the present invention includes a first image forming step of irradiating a first image and forming an image at a first distance d1, and a second image forming step of irradiating a second image and forming an image at a second distance different from the first distance d1. a second image forming step of forming an image at a distance d2; and a control step of controlling display of the first image and the second image, wherein the control step delays display timing of the first image by a first delay. It is characterized by comprising an image delay step of delaying the image by time Δt1 and using it as the second image.

INDUSTRIAL APPLICABILITY The present invention can provide an image display device and an image display method that allow a viewer to easily recognize display contents even when an image that changes over time is formed in the air.

1 is a block diagram showing the configuration of an image display device 100 according to a first embodiment; FIG. 1 is a schematic diagram showing a structural example of an image display device 100 and an image display method according to a first embodiment; FIG. 4 is a timing chart schematically showing display timings of a first image A1 and a second image A2 in the first embodiment; FIG. 3 is a schematic diagram showing the relationship between a first image A1 and a second image A2 visually recognized by a viewer in the first embodiment; 4 is a flowchart showing an image display method according to the first embodiment; FIG. 6A is a photograph showing a state in which images are formed at different positions using blue light (B) and green light (G) in the first embodiment, and FIG. 6A shows a state in which only green light is formed; 6(b) shows a state in which only blue light is formed, FIG. 6(c) shows a state in which both green light and blue light are formed, and FIG. 6(d) shows a state in which green light and blue light are formed. A state in which a background image is projected in addition to image formation is shown. FIG. 3 is a block diagram showing the configuration of an image display device 110 according to a second embodiment; FIG. FIG. 10 is a schematic diagram showing a structural example of an image display device 110 and an image display method according to a second embodiment; 9 is a timing chart schematically showing display timings of a first image A1, a second image A2, and a third image A3 in the second embodiment; FIG. 10 is a schematic diagram showing the relationship among a first image A1, a second image A2, and a third image A3 visually recognized by a viewer in the second embodiment;

(First embodiment)
BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent constituent elements, members, and processes shown in each drawing are denoted by the same reference numerals, and duplication of description will be omitted as appropriate. FIG. 1 is a block diagram showing the configuration of an image display device 100 according to this embodiment. As shown in FIG. 1, the image display device 100 includes a control unit 10, a first image projection unit 20, a first imaging optical unit 30, a second image projection unit 40, and a second imaging optical unit 50. , and an image delay unit 60 .

The control section 10 is a section that is connected to each section of the image display device 100 to control operations. Although the configuration of the control unit 10 is not limited, as an example, it includes a CPU (Central Processing Unit) for performing information processing, a memory device, a recording medium, an information communication device, etc., and controls the operation of each unit according to a predetermined program. do. Also, the control unit 10 sends information including the image to the first image projection unit 20 and the image delay unit 60 .

The first image projection unit 20 is a device that emits first light including a first image based on information including an image from the control unit 10 . The second image projection unit 40 is a device that emits second light containing a second image based on the information containing the image from the image delay unit 60 . The configurations of the first image projection unit 20 and the second image projection unit 40 are not limited, but conventionally known ones such as a liquid crystal display device, an organic EL display device, and a combination of a laser light source and an optical modulation element can be used. Examples of the light modulation element include a scanning mirror device (SMD) and a digital mirror device (DMD).

The first imaging optical section 30 is an optical member for forming an image in the air of the light including the first image emitted from the first image projection section 20 to reach the viewpoint of the viewer. The first imaging optical unit 30 forms a first image in the air at a first distance d1 from the reference position. The second imaging optical unit 50 is an optical member for forming an image in the air, including the second image, emitted from the second image projection unit 40 and reaching the viewpoint of the viewer. The second imaging optical unit 50 forms a first image in the air at a second distance d2 from the reference position, and causes the first light to reach the viewer's viewpoint position. The difference between the first distance d1 and the second distance d2 is Δd1. Here, the reference position may be the viewer's viewpoint, or may be the distance from any member of the image display device 100 .

The image delay unit 60 is a part that delays the information including the image sent from the control unit 10 by the first delay time Δt1 and transmits the information including the second image to the second image projection unit 40 . The configuration of the image delay unit 60 is not limited, and a delay circuit that delays and transmits an electrical signal may be used, or information including an image may be temporarily stored and transmitted after a predetermined time has elapsed. Further, although FIG. 1 shows an example in which the control unit 10 and the image delay unit 60 are separated into separate configurations, the functions of the image delay unit 60 may be included in a part of the control unit 10 and executed as software. .

Information including an image sent from the control unit 10 is the same as that for the first image projection unit 20 . Therefore, the content of the second image projected from the second image projection unit 40 is the same as that of the first image, and the display timing is delayed by the first delay time Δt1. A combination of the control unit 10 and the image delay unit 60 corresponds to the image control unit in the present invention.

FIG. 2 is a schematic diagram showing a structural example of the image display device 100 and an image display method according to this embodiment. As shown in FIG. 2 , information including the same image is transmitted from the control unit 10 to the first image projection unit 20 and the image delay unit 60 , and the second image projection unit 40 receives the first image from the image delay unit 60 . Information including an image is transmitted with a delay of Δt1.

The first light emitted by the first image projection unit 20 passes through the polarizing plate 31 , the lens 32 and the mirrors 33 and 34 and enters the diffraction grating unit 35 . Also, the second light emitted by the second image projection unit 40 passes through the polarizing plate 51 and the lens 52 and enters the diffraction grating unit 35 . The first light and the second light incident on the diffraction grating portion 35 at the first angle and the second angle, respectively, are diffracted by the diffraction grating portion 35 and enter the light guide plate portion 36 , and part of the light enters the light guide plate portion 36 . The light is repeatedly totally reflected inside the beam splitter 37 and reaches the partial reflection portion 38 provided at the end portion of the light guide plate portion 36 .

Part of the first light and the second light is reflected by the partial reflection section 38, returns to the beam splitter 37, is reflected by the beam splitter 37, is taken out of the light guide plate section 36, and reaches the position of the viewer's viewpoint e. direction. At this time, the first light and the second light reach the viewpoint e with different spread angles because the lenses 32 and 52 and the diffraction grating section 35 have different spread angles and optical path lengths. Therefore, at the viewpoint e, the first image A<b>1 and the second image A<b>2 appear to be formed at a position deeper than the light guide plate portion 36 .

The first light and the second light that have not been reflected by the partial reflection portion 38 are transmitted and reach the retroreflection portion 39 . Since the retroreflective portion 39 retroreflects the light in the direction in which the light is incident, the light whose light diameter has increased is reflected as light whose light diameter has decreased. Therefore, the first light and the second light retroreflected by the retroreflecting portion 39 are reflected by the beam splitter 37, and then imaged between the light guide plate portion 36 and the viewpoint e to reach the viewpoint e. Therefore, at the point of view e, the first image A1 and the second image A2 are viewed as if they were also formed at a position in front of the light guide plate portion 36 .

Here, the combination of the polarizing plate 31, the lens 32, the mirrors 33 and 34, the diffraction grating portion 35, the light guide plate portion 36, the beam splitter 37, the partial reflection portion 38 and the retroreflection portion 39 is the first imaging optical system of the present invention. It corresponds to section 30 . Also, the combination of the polarizing plate 51, the lens 52, the diffraction grating section 35, the light guide plate section 36, the beam splitter 37, the partial reflection section 38 and the retroreflection section 39 corresponds to the second imaging optical section 50 of the present invention. there is

As described above, in the image display device 100, the first image A1 and the second image A2 may be formed at a position farther from the light guide plate section 36 or at a position closer to the light guide plate section 36 as viewed from the viewpoint e. You can also Also, by appropriately setting the reflectance of the partial reflection portion 38, the contrast of the formed image can be determined. As an example, if the partial reflection portion 38 is not provided, only the retroreflected light with a reduced light diameter from the retroreflection portion 39 alone will be reflected. Two images A2 are formed. As another example, when the reflectance of the partial reflection portion 38 is close to 100% and the retroreflection portion 39 is not provided, the first image A1 and the second image A2 are displayed only at positions farther than the light guide plate portion 36. imaged.

Further, as shown in FIG. 2, an optical filter 53 and an optical shutter 54 are provided in a part of the light guide plate portion 36 so that the light that is not totally reflected and is extracted to the outside of the light guide plate portion 36 is selectively filtered by a rear screen 55 . may be irradiated.

FIG. 3 is a timing chart schematically showing display timings of the first image A1 and the second image A2 in this embodiment. FIG. 4 is a schematic diagram showing the relationship between the first image A1 and the second image A2 visually recognized by the viewer in this embodiment. Information including the first image A1 is transmitted from the control unit 10 to the first image projection unit 20 at the timing shown in FIG. As shown in FIG. 3(b), the second image projection unit 40 receives information including the second image A2 from the image delay unit 60 at a timing delayed by the first delay time Δt1 from that in FIG. 3(a). transmitted. Therefore, after the first delay time Δt1 elapses after the first image A1 is imaged and displayed at the first distance d1 at the viewer's viewpoint e, the second image A2 is imaged at the second distance d2. Is displayed.

At this time, since the first image A1 and the second image A2 have the same content, the viewer perceives the image formed at the first distance d1 as if it moved to the second distance d2 over time. . Information including images is constantly sent from the control unit 10 to the first image projection unit 20 and the image delay unit 60, and the first image A1 and the second image A2 are successively updated. Therefore, the contents of the first image A1 and the second image A2 imaged in the air at a certain moment may differ.

As shown in FIGS. 3(a) and 3(b), when the new content of the first image A1 is different from the content of the second image A2 delayed by the first delay time Δt1, the viewer will see FIG. And as shown in FIG. 4, a new first image A1 is viewed at a first distance d1, and a second image A2 having the same content as the slightly previous first image A1 is viewed at a second distance d2. In other words, the first image A1 and the second image A2 are superimposed and displayed on the same line-of-sight direction at the same viewpoint position. 2 Recognize as displayed at a distance d2. This allows the viewer to easily recognize the time-varying image formed in the air. In addition, by using the image display device 100, it is possible to provide a new viewing experience with a visual effect of visually recognizing the present and the past at the same time.

FIG. 5 is a flowchart showing an image display method according to this embodiment. Here, the process of controlling the display of the first image A1 and the second image A2 by the first image projection section 20 and the second image projection section 40 by the control section 10 corresponds to the control process in the present invention. First, in the first image preparation process of step S1, the control unit 10 sends information including an image, which is common content, to the first image projection unit 20 and the image delay unit 60. FIG. Next, in the first image forming step of step S2, the control unit 10 sets the image transmitted in the first image preparation step as the first image A1, and transmits the image from the first image projection unit 20 via the first imaging optical unit 30. to irradiate the first light containing the first image A1 to form the first image A1 at the first distance d1.

Next, in the image delay step of step S3, the image delay unit 60 delays the display timing of the image transmitted from the control unit 10 by the first delay time Δt1 to produce the second image A2. Next, in the second image forming step of step S4, the image delaying unit 60 sends information including the second image A2 to the second image projecting unit 40, and the second image projecting unit 40 transmits the second image forming optical unit. A second light containing a second image A2 is emitted via 50 to form a second image A2 at a second distance d2.

FIG. 6 is a photograph showing how images are formed at different positions using blue light (B) and green light (G) in this embodiment, and FIG. 6(b) shows a state where only blue light is imaged, FIG. 6(c) shows a state where both green light and blue light are imaged, and FIG. 6(d) shows a state where green light and blue light are imaged. It shows a state in which a background image is projected in addition to image formation with light. In FIG. 6, the camera is arranged at the viewpoint position e shown in FIG. In FIG. 6, the images formed in the air are indicated by A1(B) and A1(G), respectively, surrounded by white lines. Also, A1(B) and A1(G) are imaged at positions with different distances from the viewpoint position e, and correspond to the first image A1 and the second image A2 in the present invention, respectively.

When the image A1 (B) is focused and photographed as shown in FIG. 6A, the bolt and nut arranged for comparison on the left side of the photograph are also in focus. On the other hand, when the image A1(G) is focused and captured as shown in FIG. 6(b), the bolt and nut are out of focus. Further, as shown in FIG. 6C, the image A1(B) and the image A1(G) can be imaged at different positions at the same time and viewed. Further, as shown in FIG. 2, the background image V1B is projected onto the rear screen 55 via the optical filter 53 and the optical shutter 54, and the image A1(B) and the image A1(G) are projected as shown in FIG. 6(d). ) and the background image V1B can be viewed at the same time.

As described above, in the image display apparatus 100 of the present embodiment, after the first image is formed at the first distance d1 and the first delay time Δt1 has elapsed, the same content as the first image is used as the second image. 2. An image is formed at a distance d2. As a result, the transition of the display contents over time can be visually recognized as if the position of the afterimage changes, and even when an image that changes over time is formed in the air, the viewer can easily recognize the display contents. can. Here, it is preferable to set the first delay time Δt1 to less than 100 ms in order to allow the viewer to visually recognize the afterimage. Further, by setting the first delay time Δt1 to 100 ms or more, it is possible to give an impression of a footprint in which the first image and the second image are separated.

(Modification 1 of the first embodiment)
The image display device 100 may vary the brightness of the first image A1 projected from the first image projection unit 20 and the second image A2 projected from the second image projection unit 40 . As an example, the brightness b2 of the second image A2 is made lower than the brightness b1 of the first image A1. A method for differentiating the luminance is not limited, but one example is a method in which the control unit 10 controls the luminance of the first image projection unit 20 and the luminance of the second image projection unit 40 to be different. Also, a filter that attenuates light may be interposed in the second imaging optical section 50 .

Here, the imaging positions of the first image A1 and the second image A2 projected from the first image projection unit 20 or the second image projection unit 40 are changed, and the difference between the imaging positions of the two changes from Δd1 to Δd2. Suppose In this case, the difference in luminance between the luminance b1 and the luminance b2 of the first image A1 and the second image A2 may be changed from Δb1 to Δb2. Also, the change in luminance is inversely proportional to the change in imaging position, and Δd1:Δd2=Δb2:Δb1. Thereby, it is possible to enhance the relevance between the imaging position change and the luminance change.

In this modified example, the viewer perceives that the latest image is brightly displayed at the first distance d1 and the previous image is faded out and displayed at the second distance d2. This allows the viewer to easily recognize the time-varying image formed in the air. In addition, by using the image display device 100, it is possible to provide a new viewing experience with a visual effect such that an image that fades out from the present to the past is visually recognized at the same time.

(Modification 2 of the first embodiment)
2 to 5 show examples in which the first image A1 and the second image A2 are superimposed and displayed in the same line-of-sight direction, they may be displayed in different line-of-sight directions. In the example shown in FIG. 2, the first imaging optical section 30 and the second imaging optical section 50 share the diffraction grating section 35, the light guide plate section 36, the beam splitter 37, the partial reflection section 38, and the retroreflection section 39. and used. In this modified example, the first imaging optical unit 30 and the second imaging optical unit 50 are separated and configured separately, so that the first image A1 and the second image A2 reach the viewpoint e from different directions. As a result, the first image A1 and the second image A2 not only differ in the first distance d1 and the second distance d2, but are displayed in different fields of view. They can be distinguished and visually recognized.

2, even if the first imaging optical section 30 and the second imaging optical section 50 are partially shared, the display of the first image A1 and the second image A2 overlap. A similar effect can be obtained by separating the display areas in the air so that they do not match.

(Second embodiment)
Next, a second embodiment of the invention will be described with reference to FIGS. 7 to 10. FIG. The description of the content that overlaps with the first embodiment is omitted. FIG. 7 is a block diagram showing the configuration of the image display device 110 according to this embodiment. As shown in FIG. 7, the image display device 110 includes a control unit 10, a first image projection unit 20, a first imaging optical unit 30, a second image projection unit 40, and a second imaging optical unit 50. , an image delay unit 60 , a third image projection unit 70 and a third imaging optical unit 80 .

The control unit 10 sends information including images to the third image projection unit 70 and the image delay unit 60 . The third image projection unit 70 is a device that emits third light containing a third image based on information containing an image from the control unit 10 . The third imaging optical section 80 is an optical member for forming an image in the air of the light including the third image emitted from the third image projection section 70 and causing the light to reach the viewpoint of the viewer. The third imaging optical section 80 forms a third image in the air at a third distance d3 from the reference position. The difference between the first distance d1 and the second distance d2 is Δd1, and the difference between the first distance d1 and the third distance d3 is Δd2.

The image delay unit 60 delays the information including the image sent from the control unit 10 by a second delay time Δt2, transmits the information including the first image to the first image projection unit 20, and further delays the information including the first image. After a delay of time Δt1, the information including the second image is transmitted to the second image projection unit 40 . That is, in the image display device 110 of the present embodiment, an image having the same content is formed as the third image A3 at the third distance d3, and after the second delay time Δt2 has elapsed, is formed as the first image A1 at the first distance d1. After the lapse of the first delay time Δt1, the second image A2 is formed at the second distance d2.

FIG. 8 is a schematic diagram showing a structural example of the image display device 110 and an image display method according to this embodiment. The first light emitted by the first image projection section 20 passes through the polarizing plate 31 and the lens 32 and enters the diffraction grating section 35 . Also, the second light emitted by the second image projection unit 40 passes through the polarizing plate 51 , the lens 52 , and the mirrors 56 and 57 and enters the diffraction grating unit 35 . Also, the third light emitted by the third image projection unit 70 passes through the polarizing plate 71 , the lens 72 , and the mirrors 73 and 74 and enters the diffraction grating unit 35 . The first light, the second light, and the third light incident on the diffraction grating section 35 at the first angle, the second angle, and the third angle, respectively, are diffracted by the diffraction grating section 35 and enter the light guide plate section 36, A portion of the light is repeatedly totally reflected within the light guide plate portion 36 and passes through the beam splitter 37 to reach the partial reflection portion 38 provided at the end portion of the light guide plate portion 36 .

The light that has reached the beam splitter 37 is divided into the first image A1, the second image A2 and the first image A1, the second image A2 and the third distance d3 in the air at positions of the first distance d1, the second distance d2 and the third distance d3 in the same manner as described in the first embodiment. An image is formed as the third image A3.

Here, the combination of the polarizing plate 31, the lens 32, the diffraction grating section 35, the light guide plate section 36, the beam splitter 37, the partial reflection section 38 and the retroreflection section 39 corresponds to the first imaging optical section 30 in the present invention. ing. Also, the combination of the polarizing plate 51, the lens 52, the mirrors 56 and 57, the diffraction grating portion 35, the light guide plate portion 36, the beam splitter 37, the partial reflection portion 38 and the retroreflection portion 39 is the second imaging optical portion in the present invention. Equivalent to 50. The combination of the polarizing plate 71, the lens 72, the mirrors 73 and 74, the diffraction grating section 35, the light guide plate section 36, the beam splitter 37, the partial reflection section 38 and the retroreflection section 39 is the third imaging optical section in the present invention. Equivalent to 80.

FIG. 9 is a timing chart schematically showing display timings of the first image A1, the second image A2, and the third image A3 in this embodiment. FIG. 10 is a schematic diagram showing the relationship among the first image A1, the second image A2, and the third image A3 visually recognized by the viewer in this embodiment.

As shown in FIG. 9C, information including the third image A3 is transmitted from the control unit 10 to the third image projection unit 70 at a timing earlier than that in FIG. 9A by the second delay time Δt2. be. Information including the first image A1 is transmitted from the image delay unit 60 to the first image projection unit 20 at the timing shown in FIG. 9A. As shown in FIG. 9B, the second image projection unit 40 receives information including the second image A2 from the image delay unit 60 at a timing delayed by the first delay time Δt1 from that in FIG. 9A. transmitted.

Therefore, after the second delay time Δt2 elapses after the third image A3 is imaged and displayed at the third distance d3 at the viewer's viewpoint e, the first image A1 is imaged at the first distance d1. After the first delay time Δt1 has elapsed, the second image A2 is imaged and displayed at the second distance d2.

At this time, since the first image A1, the second image A2, and the third image A3 are images having the same content, the viewer sees the image formed at the third distance d3 as time elapses. 2 It is visually recognized as if it has moved to a distance d2. Information including images is constantly sent from the control unit 10 to the third image projection unit 70 and the image delay unit 60, and the third image A3, the first image A1, and the second image A2 are successively updated. . Therefore, the contents of the third image A3, the first image A1, and the second image A2 imaged in the air at a certain moment may differ.

As shown in FIGS. 10A to 10C, the new content of the third image A3, the first image A1 delayed by the second delay time Δt2, and the second image delayed by the first delay time Δt1 When the contents of A2 are different, the viewer visually recognizes a new third image A3 at a third distance d3, as shown in FIG. The first image A1 and the second image A2 having the same contents as the third image A3 slightly before are viewed as if they change with time. In other words, the third image A3, the first image A1, and the second image A2 are superimposed and displayed on the same line-of-sight direction at the same viewpoint position, and the viewer sees the latest image at the third distance d3, It is recognized as if the past images are displayed in order at the first distance d1 and the second distance d2. This allows the viewer to more easily recognize the time-varying image formed in the air. In addition, by using the image display device 100, it is possible to provide a new viewing experience with a visual effect of visually recognizing the present and the past at the same time.

7 to 10, the first image projection unit 20, the first imaging optical unit 30, the second image projection unit 40, the second imaging optical unit 50, the third image projection unit 70, the third imaging optical unit An example of delaying and forming an image at three positions with three combinations of 80 is shown. However, a larger number of image projection units and image forming optical units may be provided, the respective image forming positions may be made different, and the same content may be sequentially displayed by providing a delay time.

(Modification 1 of the second embodiment)
The image display device 110 displays a third image A3 projected from the third image projection unit 70, a first image A1 projected from the first image projection unit 20, and a second image projected from the second image projection unit 40. A2 may have different luminances. As an example, the brightness b2 of the third image A3 and the second image A2 is made lower than the brightness b1 of the first image A1.

In this modification, the viewer sees the latest image displayed dark at the third distance d3, the bright image faded-in displayed at the first distance d1, and the dark image faded-out displayed at the second distance d2. recognize as This allows the viewer to easily recognize the time-varying image formed in the air. In addition, by using the image display device 100, it is possible to provide a new viewing experience through visual effects such as fading in from the future to the present and fading out from the present to the past at the same time.

(Modification 2 of the second embodiment)
Further, in the image display device 110, when the difference between the first distance d1 and the second distance d2 is Δd1, and the difference between the first distance d1 and the third distance d3 is Δd2, the proportional relationship of Δd1:Δd2=Δt1:Δt2 is established. You can also set it to work. In this case, since the passage of time and the change in distance are associated, it is possible to provide an experience that expresses the passage of time using a three-dimensional space.

(Modification 3 of Second Embodiment)
Δd1 is the difference between the first distance d1 and the second distance d2, Δd2 is the difference between the first distance d1 and the third distance d3, and Δd2 is the difference between the luminance b1 of the first image A1 and the luminance b2 of the second image A2. Δb1, and the difference between the luminance b1 of the first image A1 and the luminance b3 of the third image A3 is Δb2. In this case, the image display device 110 can be set so that the relationship Δd1:Δd2=Δt1:Δt2=Δb2:Δb1 is established. In this case, since the passage of time is associated with the change in distance, it is possible to provide an experience that expresses the passage of time using a three-dimensional space.

(Third embodiment)
In the first and second embodiments, the image display devices 100 and 110 are provided with the diffraction grating portion 35 and the light guide plate portion 36, but different images can be formed at different positions in space. If there is, the configuration is not limited. As an example, a known image display device using a half mirror and a retroreflector can be used (for example, JP-A-2021-047234, JP-A-2021-089396, JP-A-2021-096284, etc. ).

The present invention is not limited to the above-described embodiments, but can be modified in various ways within the scope of the claims, and can be obtained by appropriately combining technical means disclosed in different embodiments. is also included in the technical scope of the present invention.

Reference Signs List 100, 110 Image display device 10 Control unit 20 First image projection unit 30 First imaging optical unit 40 Second image projection unit 50 Second imaging optical unit 60 Image delay unit 70 Third Image projection unit 80 Third imaging optical unit 35 Diffraction grating unit 36 Light guide plate unit 37 Beam splitter 38 Partial reflection unit 39 Retroreflection unit

Claims (9)

a first image projection unit that emits a first image;
a second image projection unit that emits a second image;
a first imaging optical unit that forms the first image at a first distance d1;
a second imaging optical unit that forms the second image at a second distance d2 different from the first distance d1;
An image control unit that controls the first image projection unit and the second image projection unit,
The image display device, wherein the image control unit includes an image delay unit that delays the display timing of the first image by a first delay time Δt1 and uses it as the second image. The image display device according to claim 1,
The image display device, wherein the image control section lowers the brightness b2 of the second image below the brightness b1 of the first image. The image display device according to claim 1 or 2,
a third image projection unit that emits a third image;
a third imaging optical unit that forms an image of the third image at a third distance d3 different from the first distance d1 and the second distance d2;
The image display device, wherein the image delay unit delays display timing of the third image by a second delay time Δt2 and uses the third image as the first image. The image display device according to claim 3,
The image display device, wherein the image control unit lowers the brightness b3 of the third image below the brightness b1 of the first image. The image display device according to claim 3 or 4,
When the difference between the first distance d1 and the second distance d2 is Δd1, and the difference between the first distance d1 and the third distance d3 is Δd2,
Δd1:Δd2=Δt1:Δt2
An image display device characterized by: The image display device according to claim 5,
When the difference between the brightness b1 of the first image A1 and the brightness b2 of the second image A2 is Δb1, and the difference between the brightness b1 and the brightness b3 of the third image A3 is Δb2,
Δd1: Δd2 = Δb2: Δb1
An image display device characterized by: The image display device according to any one of claims 1 to 6,
An image display device, wherein the first image and the second image are superimposed and displayed on the same line-of-sight direction at the same viewpoint position. The image display device according to any one of claims 1 to 6,
The image display device, wherein the first image and the second image are displayed in different line-of-sight directions at the same viewpoint position. a first image forming step of irradiating the first image and forming an image at the first distance d1;
a second image forming step of irradiating a second image and forming an image at a second distance d2 different from the first distance d1;
A control step of controlling display of the first image and the second image,
The image display method, wherein the control step includes an image delay step of delaying the display timing of the first image by a first delay time Δt1 and using it as the second image.

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