Image display device

Abstract

The beam splitter (BS2) reflects a portion of the light emitted from the first image projection unit (S1) toward the first direction, and transmits another portion of the light toward the second direction. The first retro-reflection unit (RR1) retro-reflects the light reflected toward the first direction toward the beam splitter (BS2). The second retro-reflection unit (RR2) retro-reflects the light transmitted toward the second direction toward the beam splitter (BS2). The beam splitter (BS2) transmits the light retro-reflected by the first retro-reflection unit (RR1) toward the imaging optical unit (DM), and reflects the light retro-reflected by the second retro-reflection unit (RR2) toward the imaging optical unit (DM).

Description

Technical Field

[0001] The present invention relates to an image display device that displays a projected image in a manner that appears to overlap with a background. Background Art

[0002] As an example of the above-mentioned image display device, Patent Document 1 discloses a head-mounted head-up display (hereinafter referred to as HUD: Head-Up Display).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2018-528446 Summary of the invention

[0006] Technical problem that the invention aims to solve

[0007] There is a need to improve the convenience of the above-mentioned image display device that displays a projected image so that it appears to overlap with a background.

[0008] Technical solutions to the problem

[0009] As a solution for addressing the above-mentioned needs, an image display device is provided, comprising: a first image projection unit, which emits light corresponding to a first image projected toward a user's eye; a beam splitter, which reflects a portion of the light emitted from the first image projection unit toward a first direction, and transmits another portion of the light toward a second direction; a first retroreflection unit, which retroreflects the light reflected in the first direction toward the beam splitter; a second retroreflection unit, which retroreflects the light transmitted in the second direction toward the beam splitter; and an imaging optical unit, which images the incident light in a space arranged between the user's eye and a background, and the beam splitter transmits the light retroreflected by the first retroreflection unit toward the imaging optical unit, and reflects the light retroreflected by the second retroreflection unit toward the imaging optical unit.

[0010] According to the above structure, since both the light reflected by the beam splitter and the light transmitted through the beam splitter are used for imaging by the imaging optical unit, the brightness of the image formed in the space between the user's eyes and the background is suppressed from decreasing, and the visibility of the image is improved. Therefore, the convenience of the image display device that displays the projected image in a manner that appears to overlap the background can be improved.

[0011] As a solution for meeting the above-mentioned needs, an image display device is provided, comprising: a first image projection unit, which is driven by a signal input from an image signal input unit and emits light corresponding to a first image projected toward a user's eye; a second image projection unit, which is driven by a signal input from the image signal input unit and emits light corresponding to a second image projected toward the user's eye; an imaging optical unit, which forms an image corresponding to the incident light in a space arranged between the user's eye and a background; and a beam splitter, which reflects light from the first image projection unit that is incident on a first surface toward the imaging optical unit, and transmits light from the second image projection unit that is incident on a second surface toward the imaging optical unit.

[0012] According to the above structure, the first image projection unit and the second image projection unit for imaging multiple images in the space between the user's eyes and the background operate according to the signal input from the common image signal input unit. As a result, compared with a structure in which a separate image projection device is allocated to each of the multiple images to be imaged and the drive control is performed through a separate wiring, it is possible to suppress an increase in the number of components, an increase in the size and weight of the device, and a complication of the device structure. Therefore, it is possible to improve the convenience of the image display device that displays the projected image in a manner that appears to overlap the background.

[0013] As a solution for meeting the above-mentioned needs, an image display device is provided, comprising: a light source unit, which emits a laser corresponding to an image projected onto a user's eye; a first imaging optical unit, which forms an image corresponding to the incident light at a first position in a space arranged between the user's eye and a background; a second imaging optical unit, which forms an image corresponding to the incident light at a second position in the space that is different from the first position; and a first beam splitter, which reflects a portion of the laser light toward one of the first imaging optical unit and the second imaging optical unit, and transmits another portion of the laser light toward the other of the first imaging optical unit and the second imaging optical unit.

[0014] According to the above structure, even if a single light source unit is used, the image projected to the user's eyes can be formed at multiple positions different in the depth direction. In addition, since the laser light emitted from the light source unit and then transmitted through the first beam splitter and the laser light emitted from the light source unit and then reflected by the first beam splitter are respectively provided to different imaging optical systems for imaging, the degree of freedom related to the adjustment of the imaging position can be increased. Therefore, the convenience of the image display device that displays the projected image in a manner that appears to overlap with the background can be improved.

[0015] As a solution for addressing the above-mentioned needs, an image display device is provided, comprising: a first image projection unit, which emits light corresponding to a first image projected toward a user's eye; a second image projection unit, which emits light corresponding to a second image projected toward the user's eye; an imaging optical unit, which images the first image at a first position in a space between the user's eye and a background, and images the second image at a second position in the space that is different from the first position; and a control unit, which controls the first image projection unit and the second image projection unit so that a balance between the brightness of the first image and the brightness of the second image changes over time.

[0016] According to the above configuration, the user can visually recognize a three-dimensional illusion image in front of the background. Therefore, the convenience of the image display device that displays the projected image so that it appears to overlap with the background can be improved.

[0017] It should be noted that the expression "toward the (nth) imaging optical section" used in this specification is not limited to a description of a structure in which a certain optical component directly transmits or reflects light toward the (nth) imaging optical section. This expression means that if the light that has transmitted through the optical component or the light that has been reflected finally reaches the (nth) imaging optical section, other optical components may be interposed between the optical component and the (nth) imaging optical section. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The structure of the image display device according to the first embodiment is exemplified.

[0019] Figure 2 Shown is the Figure 1 A comparative example is provided to illustrate the advantages of the second retro-reflective portion.

[0020] Figure 3 It is used to illustrate Figure 1 A diagram illustrating the advantages of an exemplary second retro-reflective portion.

[0021] Figure 4 It is used to illustrate Figure 1 A diagram illustrating the advantages of an exemplary second retro-reflective portion.

[0022] Figure 5 Shows Figure 1 Another structural example of the image display device of the example.

[0023] Figure 6 Shows Figure 1 Another structural example of the image display device of the example.

[0024] Figure 7 It is used to illustrate Figure 6 A diagram illustrating the operation of an exemplary image display device.

[0025] Figure 8 Shows Figure 1 Another structural example of the image display device of the example.

[0026] Fig. 9 It is used to illustrate Figure 8 A diagram illustrating the operation of an exemplary image display device.

[0027] Fig.10 The structure of the image display device according to the second embodiment is exemplified.

[0028] Fig.11 Shows Fig.10 Another structural example of the image display device of the example.

[0029] Fig.12 Shows Fig.10 Another structural example of the image display device of the example.

[0030] Fig.13 The structure of the image display device according to the third embodiment is exemplified.

[0031] Fig.14 Example Fig.13 Operation of a portion of an exemplary image display device.

[0032] Fig.15 Example Fig.13 The exemplary image shows the operation of another part of the device.

[0033] Fig.16 Example through Fig.13 An example of an image display device showing a real aerial scene.

[0034] Fig.17 Shows Fig.13 Other structural examples of the exemplary image display device.

[0035] Fig.18 Example through Fig.17 An example of an image display device showing a real aerial scene.

[0036] Fig.19 The structure of the image display device according to the fourth embodiment is exemplified.

[0037] Fig. 20 Example Fig.19 Functional structure of an exemplary image display device.

[0038] Fig.21 Shows Fig.19An example of the operation of the exemplary image display device.

[0039] Fig. 22 Shows Fig.19 Another example of the operation of the exemplary image display device.

[0040] Fig.23 Shows Fig.19 Another example of the operation of the exemplary image display device. DETAILED DESCRIPTION

[0041] Hereinafter, the embodiment examples will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in the respective drawings are denoted by the same reference numerals, and duplicate descriptions are omitted as appropriate.

[0042] Figure 1 The configuration of the image display device 100 according to the first embodiment is exemplified. The image display device 100 includes a first beam splitter BS1, a first image projection unit S1, a second image projection unit S2, and a head mounted display HMD.

[0043] By using the image display device 100, the user visually recognizes the first image A1 projected from the first image projection unit S1, the second image A2 projected from the second image projection unit S2, and the third image H projected from the head mounted display HMD as different positions in the depth direction. In the following description, the direction in which the first image A1, the second image A2, and the third image H are arranged is referred to as the depth direction. Figure 1 The direction corresponding to the up-down direction is defined as the up-down direction. The direction orthogonal to the depth direction and the up-down direction is defined as the left-right direction. The expressions of these directions are used for convenience of explanation and are not intended to limit the posture of the image display device 100 when it is actually used.

[0044] The first beam splitter BS1 is a component that transmits a portion of the incident light and reflects a portion. As the first beam splitter BS1, a partial reflection plate having a film formed on the surface to adjust the reflectivity can be used. The first beam splitter BS1 is configured to form an angle of 45 degrees with the vertical direction and the depth direction. The first beam splitter BS1 is configured to form an angle of 45 degrees with the optical axes of the light emitted from the first image projection unit S1 and the second image projection unit S2, respectively.

[0045] The image display device 100 includes a first retro-reflective portion RR1, a second retro-reflective portion RR2, and a second beam splitter BS2. The first retro-reflective portion RR1 and the second retro-reflective portion RR2 are optical components that reflect incident light relative to the incident direction in a state of maintaining light-convergence. As each of the first retro-reflective portion RR1 and the second retro-reflective portion RR2, a structure in which tiny glass beads are laid on the surface side of a reflective film or a structure using a prism can be used. The first retro-reflective portion RR1 is arranged below the second beam splitter BS2. The first retro-reflective portion RR1 is arranged in a manner such that the main surface faces the up-and-down direction. The second retro-reflective portion RR2 is arranged in a manner such that it is arranged in the depth direction with the first beam splitter BS1 and the second beam splitter BS2. The second retro-reflective portion RR2 is arranged in a manner such that the main surface faces the depth direction. The expression "main surface" used in this specification refers to the surface with the largest area in a plate-like member.

[0046] The second beam splitter BS2 is a component that transmits a part of the incident light and reflects a part of the incident light. As the second beam splitter BS2, a partial reflection plate with a film formed on the surface to adjust the reflectivity can be used. The second beam splitter BS2 is configured in a manner that forms an angle of 45 degrees with the up-down direction and the depth direction. The second beam splitter BS2 is configured in a manner that forms an angle of 45 degrees with the optical axis of the light emitted from the first image projection unit S1 and the second image projection unit S2 respectively. The second beam splitter BS2 is tilted in the opposite direction to the first beam splitter BS1. The first beam splitter BS1 and the second beam splitter BS2 are configured in a manner that is opposite to each other in the depth direction.

[0047] For each of the first beam splitter BS1 and the second beam splitter BS2, the transmittance and reflectance of light can be selected to be an arbitrary balance. For example, the transmittance and reflectance can be 50% respectively. The inclination angles of the first beam splitter BS1 and the second beam splitter BS2 relative to the optical axis of the light emitted from the first image projection unit S1 and the optical axis of the light emitted from the second image projection unit S2 are not limited to 45 degrees. Each inclination angle can be appropriately determined according to the relationship between the position of the first image projection unit S1, the position of the second image projection unit S2, and the imaging position of the image.

[0048] The image display device 100 includes a dichroic mirror DM. The dichroic mirror DM is an optical component that reflects light of a specific wavelength and allows light of other wavelengths to pass through. The dichroic mirror DM is arranged above the first retro-reflective portion RR1 and the second beam splitter BS2. The dichroic mirror DM is arranged in a manner that forms an angle of 45 degrees with the depth direction. The dichroic mirror DM is configured to reflect the wavelengths of visible light emitted from the first image projection portion S1 and the second image projection portion S2 respectively, and allow other wavelengths of visible light to pass through. The dichroic mirror DM is an example of an imaging optical portion.

[0049] At least one imaging lens may be disposed between the second beam splitter BS2 and the dichroic mirror DM. The imaging lens is an optical component for imaging the light transmitted through the second beam splitter BS2 at a predetermined position in space.

[0050] The head mounted display HMD is a device that forms an image of the third image H in a space between the user's eyes and the background. The head mounted display HMD is an example of a third image projection unit. As the head mounted display HMD, the following well-known structures can be used: a head mounted display using a light guide plate and a diffraction grating, a head mounted display using a light guide plate and an optical element, etc.

[0051] The first image projection unit S1, the second image projection unit S2 and the head mounted display HMD are devices that emit light constituting an image. The first image projection unit S1, the second image projection unit S2 and the head mounted display HMD form images at positions at different distances from the user's eyes. The first image projection unit S1 is arranged below the first beam splitter BS1. The first image projection unit S1 emits light to the surface of the first beam splitter BS1 that is opposite to the second beam splitter BS2. The second image projection unit S2 is arranged in a manner that is arranged in the depth direction with the first beam splitter BS1, the second beam splitter BS2 and the second retro-reflective unit RR2. The second image projection unit S2 emits light to the surface of the first beam splitter BS1 that is not opposite to the second beam splitter BS2. The head mounted display HMD is arranged to be located between the user's eyes and the dichroic mirror DM.

[0052] As the first image projection unit S1 and the second image projection unit S2, a liquid crystal display device with a backlight, a self-luminous organic EL display device, a projector device using a light source and a modulation element, etc. can be used. The images projected by the first image projection unit S1, the second image projection unit S2, and the head-mounted display HMD can be still images or dynamic images. The projected images can be the same or different from each other. The first image projection unit S1, the second image projection unit S2, and the head-mounted display HMD can each be appropriately equipped with optical components such as lenses.

[0053] The dashed line indicates the path of light emitted from the first image projection unit S1 to project the first image A1. The dotted line indicates the path of light emitted from the second image projection unit S2 to project the second image A2. The double-dashed line indicates the path of light emitted from the head mounted display HMD to project the third image H.

[0054] A portion of the light emitted from the first image projection unit S1 is reflected by the first beam splitter BS1 and is incident on the second beam splitter BS2. A portion of the light is reflected by the second beam splitter BS2 and is incident on the first retro-reflection unit RR1. The light is retro-reflected by the first retro-reflection unit RR1 and is incident on the second beam splitter BS2 again. A portion of the light that is incident on the second beam splitter BS2 again passes through the second beam splitter BS2 and is reflected by the dichroic mirror DM. The light reflected by the dichroic mirror DM is imaged as a first image A1 at a position at a first distance from the dichroic mirror DM. The light imaged as the first image A1 passes through the head-mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the first image A1 through the head-mounted display HMD.

[0055] A portion of the light emitted from the second image projection unit S2 passes through the first beam splitter BS1 and is incident on the second beam splitter BS2. A portion of the light is reflected by the second beam splitter BS2 and is incident on the first retro-reflection unit RR1. The light is retro-reflected by the first retro-reflection unit RR1 and is incident on the second beam splitter BS2 again. A portion of the light that is incident on the second beam splitter BS2 again passes through the second beam splitter BS2 and is reflected by the dichroic mirror DM. The light reflected by the dichroic mirror DM is imaged as a second image A2 at a position a second distance from the dichroic mirror DM. The second distance is longer than the first distance. The light imaged as the second image A2 passes through the head-mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the second image A2 in front of the first image A1 through the head-mounted display HMD.

[0056] The light emitted from the head mounted display HMD is imaged as a third image H at a position of a third distance from the head mounted display. The third distance is determined by the optical system of the head mounted display HMD. The third distance is determined so that the distance from the dichroic mirror DM is different from both the first distance and the second distance. The third distance is determined so that the imaging position of the third image H is located on the side opposite to the imaging position of the first image A1 and the imaging position of the second image A2 with respect to the dichroic mirror DM. Therefore, the user visually recognizes the third image H behind the first image A1 and the second image A2 through the head mounted display HMD.

[0057] At the same time, light from the background passes through the dichroic mirror DM and the head mounted display HMD to reach the user's eyes. Therefore, the user visually recognizes the first image A1, the second image A2, and the third image H at different positions in the depth direction as a real aerial scene overlapping the background.

[0058] The image display device 100 includes a second retro-reflective portion RR2. Figure 2 and Figure 3 , the advantages of the second retro-reflective portion RR2 are explained.

[0059] Figure 2A comparative example in which the second retro-reflection unit RR2 is not used is shown. In this case, the light emitted from the first image projection unit S1 and imaged as the first image A1' is only the light that reaches the dichroic mirror DM after being retro-reflected by the first retro-reflection unit RR1 and passing through the second beam splitter BS2. Therefore, the light that initially passes through the second beam splitter BS2 among the light reflected by the first beam splitter BS1 is not used for imaging the first image A1'.

[0060] On the other hand, Figure 3 As shown in the example, when the first retro-reflection unit RR1 and the second retro-reflection unit RR2 are used, the light reflected by the first beam splitter BS1 and initially passed through the second beam splitter BS2 is incident on the second retro-reflection unit RR2. As a result, the light retro-reflected by the second retro-reflection unit RR2 is also reflected by the second beam splitter BS2 and reaches the dichroic mirror DM. Therefore, the light reflected by the first beam splitter BS1 and initially passed through the second beam splitter BS2 is also used for imaging the first image A1, so that the light amount reduction of the first image A1 can be suppressed.

[0061] At this time, the light retroreflected by the first retroreflection unit RR1 and the light retroreflected by the second retroreflection unit RR2 correspond to the same projection image, and therefore need to arrive at the same position in the dichroic mirror DM at the same time. Therefore, when the optical characteristics of the first retroreflection unit RR1 and the second retroreflection unit RR2 are the same, it is preferred to make the distance from the first retroreflection unit RR1 to the second beam splitter BS2 and the distance from the second retroreflection unit RR2 to the second beam splitter BS2 equal.

[0062] Figure 4 Example through Figure 2 The observation result of the first image A1' projected by the structure of the example, and the ... Figure 3 Observation results of the first image A1 projected from the example structure. Figure 4 The observation results of the position dependence of the light amount of the first image A1' at a specific position in the Y direction along the X direction and the position dependence of the light amount of the first image A1 along the X direction are also illustrated. The observation results involving the first image A1' are indicated by solid lines. The observation results involving the first image A1 are indicated by dotted lines.

[0063] It can be seen that the light amount of A1 imaged using both the first re-reflection unit RR1 and the second re-reflection unit RR2 is higher than the light amount of the first image A1' imaged using only the first re-reflection unit RR1. That is, the light reflected by the first beam splitter BS1 and initially transmitted through the second beam splitter BS2 is also used to image the first image A1, thereby confirming that the reduction in light amount is suppressed.

[0064] For the same reason, the second image A2 projected from the second image projection unit S2 can also suppress the reduction in light quantity. In other words, since the reduction in light quantity of the plurality of images formed in a manner arranged in the depth direction is suppressed, the visibility of the image displayed by the image display device 100 can be improved. Therefore, the convenience of the image display device that displays the projected image in a manner that appears to overlap the background can be improved.

[0065] In addition, if Figure 5 As an example, in the image display device 100 , the head mounted display HMD may be omitted.

[0066] like Figure 6 As an example, the image display device 100 may include a first drive unit D1. The first drive unit D1 is a device that mechanically changes the position and angle of the first image projection unit S1, and is configured to change the relative position with the second beam splitter BS2 by moving the first image projection unit S1.

[0067] As the first drive unit D1, a known motor or actuator can be used. When the first drive unit D1 moves the first image projection unit S1 in the direction of the arrow along the depth direction, the imaging position of the first image A1 changes in the direction of the arrow along the vertical direction. Although not shown in the figure, when the first drive unit D1 moves the first image projection unit S1 in the left-right direction, the imaging position of the first image A1 also changes in the left-right direction. When the first drive unit D1 moves the first image projection unit S1 in the vertical direction, the imaging position of the first image A1 changes in the depth direction.

[0068] Figure 7 The symbol I in the example is Figure 6 Observation results of the first image A1 and the second image A2 projected by the exemplary structure Symbol II illustrates the observation results of the first image A1 and the second image A2 projected in a state where the first image projection unit S1 is moved by the first driving unit D1. Figure 7 The observation results of the position dependence of the light amount of the first image A1 and the position dependence of the light amount of the second image A2 along the X direction at a specific position in the Y direction are also illustrated. The observation results related to the state of symbol I are indicated by a dotted line. The observation results related to the state of symbol II are indicated by a solid line.

[0069] It can be confirmed that the image formation position of the first image A1 changes by moving the first image projection unit S1 by the first drive unit D1. In this example, since the position of the second image projection unit S2 does not change, the image formation position of the second image A2 does not change.

[0070] That is, according to Figure 6In the exemplary configuration, the position of the first image A1 relative to the second image A2 can be changed by changing the relative position of the first image projector S1 and the second beam splitter BS2 while the first image A1 and the second image A2 are projected to be aligned in the depth direction.

[0071] like Figure 8 As shown in the example, the image display device 100 may include a second drive unit D2 that mechanically changes the position and angle of the second image projection unit S2 and is configured to change the relative position between the second image projection unit S2 and the second beam splitter BS2 by moving the second image projection unit S2.

[0072] As the second drive unit D2, a known motor or actuator can be used. When the second drive unit D2 moves the second image projection unit S2 in the direction of the arrow along the up-down direction, the imaging position of the second image A2 changes in the direction of the arrow along the up-down direction. Although not shown in the figure, when the second drive unit D2 moves the second image projection unit S2 in the left-right direction, the imaging position of the second image A2 also changes in the left-right direction. When the second drive unit D2 moves the second image projection unit S2 in the depth direction, the imaging position of the second image A2 also changes in the depth direction.

[0073] Fig. 9 The symbol I in the example is Figure 8 Observation results of the first image A1 and the second image A2 projected by the exemplary structure Symbol II illustrates the observation results of the first image A1 and the second image A2 projected in a state where the first image projection unit S1 is moved by the first driving unit D1. Fig. 9 The observation results of the position dependence of the light amount of the first image A1 and the position dependence of the light amount of the second image A2 along the X direction at a specific position in the Y direction are also illustrated. The observation results related to the state of symbol I are indicated by a dotted line. The observation results related to the state of symbol II are indicated by a solid line.

[0074] It can be confirmed that the imaging position of the second image A2 changes by moving the second image projection unit S2 using the second drive unit D2. In this example, since the position of the first image projection unit S1 is not changed, the imaging position of the first image A1 does not change.

[0075] That is, according to Figure 8 In the exemplary configuration, when the first image A1 and the second image A2 are projected to be aligned in the depth direction, the position of the second image A2 relative to the first image A1 can be changed by changing the relative position of the second image projector S2 and the second beam splitter BS2.

[0076] By combination Figure 6 The first drive unit D1 and Figure 8 The second driving unit D2 of the example can change the relative position of the first image A1 and the second image A2 which are projected so as to be aligned in the depth direction.

[0077] The configuration of the first embodiment described above is merely an example for facilitating understanding of the present invention, and the configuration of the first embodiment can be appropriately changed or improved without departing from the gist of the present invention.

[0078] exist Figure 1 In the example structure, the positions of the first image A1, the second image A2, and the third image H visually recognized by the user are different in the depth direction. However, at least one of the positions of the first image A1, the second image A2, and the third image H may be the same as at least one of the other two positions in the depth direction.

[0079] exist Figure 5 , Figure 6 as well as Figure 8 In the configurations of the respective examples, the position of the first image A1 and the position of the second image A2 visually recognized by the user are different in the depth direction. However, the position of the first image A1 and the position of the second image A2 may be the same in the depth direction.

[0080] Fig.10 The structure of the image display device 200 according to the second embodiment is exemplified. Figure 1 Substantially the same components of the image display device 100 of the example are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0081] The image display device 200 includes an image projection device S. The image projection device S includes a first image projection unit S1, a second image projection unit S2, and a third image projection unit S3. The first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 are arranged at different positions in the image projection device S. The first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 are each configured to display an image.

[0082] By using the image display device 200, the user visually recognizes the first image A1 displayed by the first image projection unit S1, the second image A2 displayed by the second image projection unit S2, the third image A3 displayed by the third image projection unit S3, and the fourth image H projected from the head-mounted display HMD as different positions in the depth direction.

[0083] The image display device 200 includes a third beam splitter BS3. The third beam splitter BS3 is a component that transmits a portion of the incident light and reflects a portion of the incident light. As the third beam splitter BS3, a partial reflection plate having a film formed on the surface for adjusting the reflectivity can be used. The third beam splitter BS3 is configured in a manner that forms an angle of 45 degrees with the up-down direction and the depth direction. The third beam splitter BS3 is configured in a manner that also forms an angle of 45 degrees with the optical axis of the light emitted from the second image projection unit S2 and the third image projection unit S3 respectively. The third beam splitter BS3 is configured in a manner that is arranged in the depth direction with the first beam splitter BS1 and the second beam splitter BS2. The first beam splitter BS1 is configured between the second beam splitter BS2 and the third beam splitter BS3 in the depth direction.

[0084] In the third beam splitter BS3, the transmittance and reflectance of the light can be selected to be arbitrarily balanced. For example, the transmittance and reflectance can be 50% respectively. The inclination angle of the third beam splitter BS3 relative to the optical axis of the light emitted from the second image projection unit S2 and the optical axis of the light emitted from the third image projection unit S3 is not limited to 45 degrees. The inclination angle can be appropriately determined according to the relationship between the position of the second image projection unit S2, the position of the third image projection unit S3 and the imaging position of the image.

[0085] The image projection device S is a device that emits light constituting an image. The image projection device S and the head mounted display HMD form images at positions different distances from the user's eyes. The first image projection unit S1 is arranged below the first beam splitter BS1. The first image projection unit S1 emits light to the surface of the first beam splitter BS1 that is opposite to the second beam splitter BS2. The second image projection unit S2 is arranged in a manner arranged in the depth direction with the first beam splitter BS1, the second beam splitter BS2, the third beam splitter BS3 and the second retro-reflection unit RR2. The second image projection unit S2 emits light to the surface of the third beam splitter BS3 that is not opposite to the first beam splitter BS1. The third image projection unit S3 is arranged below the third beam splitter BS3. The third image projection unit S3 emits light to the surface of the third beam splitter BS3 that is opposite to the first beam splitter BS1.

[0086] The image projection device S is a device that displays an image by being driven by a signal input from an image signal input unit (not shown). The first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 are driven by signals input from a common image signal input unit. The image projection device S has two planes that form a curved portion. As the image projection device S, for example, a flexible organic EL element or an inorganic EL element can be used.

[0087] The image display device 200 includes a first electromagnetic shutter ES1, a second electromagnetic shutter ES2, and a third electromagnetic shutter ES3. The first electromagnetic shutter ES1 is arranged to face the light emitting surface of the first image projection unit S1. The second electromagnetic shutter ES2 is arranged to face the light emitting surface of the second image projection unit S2. The third electromagnetic shutter ES3 is arranged to face the light emitting surface of the third image projection unit S3. The first electromagnetic shutter ES1, the second electromagnetic shutter ES2, and the third electromagnetic shutter ES3 are optical components that control the transmission and shielding of light, respectively. As each of the first electromagnetic shutter ES1, the second electromagnetic shutter ES2, and the third electromagnetic shutter ES3, for example, a liquid crystal shutter can be used.

[0088] The images projected by the first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 may be still images or dynamic images. The projected images may be the same or different from each other. The first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 may each be appropriately equipped with optical components such as lenses at positions facing the light emission surface.

[0089] Similar to the image display device 100 involved in the first embodiment, a part of the light emitted from the first image projection unit S1 is reflected by the first beam splitter BS1 and incident on the second beam splitter BS2. A part of the light is reflected by the second beam splitter BS2 and incident on the first retro-reflection unit RR1. The light is retro-reflected by the first retro-reflection unit RR1 and then incident on the second beam splitter BS2. A part of the light that is incident on the second beam splitter BS2 again passes through the second beam splitter BS2 and is reflected by the dichroic mirror DM. The light reflected by the dichroic mirror DM is imaged as the first image A1 at a position of a first distance from the dichroic mirror DM. The light imaged as the first image A1 passes through the head-mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the first image A1 through the head-mounted display HMD.

[0090] A portion of the light emitted from the second image projection unit S2 passes through the third beam splitter BS3 and the first beam splitter BS1 and is incident on the second beam splitter BS2. A portion of the light is reflected by the second beam splitter BS2 and is incident on the first retro-reflection unit RR1. The remaining portion of the light passes through the second beam splitter BS2 and is incident on the second retro-reflection unit RR2. A portion of the light retro-reflected by the first retro-reflection unit RR1 passes through the second beam splitter BS2 again and is incident on the dichroic mirror DM. A portion of the light retro-reflected by the second retro-reflection unit RR2 is reflected again by the second beam splitter BS2 and is incident on the dichroic mirror DM. The light reflected by the dichroic mirror DM is imaged as a second image A2 at a position at a second distance from the dichroic mirror DM. The second distance is longer than the first distance. The light imaged as the second image A2 passes through the head-mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the second image A2 in front of the first image A1 through the head-mounted display HMD.

[0091] A portion of the light emitted from the third image projection unit S3 is reflected by the third beam splitter BS3, passes through the first beam splitter BS1, and is incident on the second beam splitter BS2. A portion of the light is reflected by the second beam splitter BS2 and is incident on the first retro-reflection unit RR1. The remaining portion of the light passes through the second beam splitter BS2 and is incident on the second retro-reflection unit RR2. A portion of the light retro-reflected by the first retro-reflection unit RR1 passes through the second beam splitter BS2 again and is incident on the dichroic mirror DM. A portion of the light retro-reflected by the second retro-reflection unit RR2 is reflected again by the second beam splitter BS2 and is incident on the dichroic mirror DM. The light reflected by the dichroic mirror DM is imaged as a third image A3 at a position of a third distance from the dichroic mirror DM. The third distance is longer than the first distance and shorter than the second distance. The light imaged as the third image A3 passes through the head-mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the third image A3 through the head-mounted display HMD in front of the first image A1 and behind the second image A2.

[0092] The light emitted from the head mounted display HMD is imaged as a fourth image H at a position at a fourth distance from the head mounted display. The fourth distance is determined by the optical system of the head mounted display HMD. The fourth distance is determined so that the distance from the dichroic mirror DM is different from the first distance, the second distance, and the third distance. The fourth distance is determined so that the imaging position of the fourth image H is located on the opposite side of the imaging position of the first image A1, the imaging position of the second image A2, and the imaging position of the third image A3 relative to the dichroic mirror DM. Therefore, the user visually recognizes the fourth image H behind the first image A1, the second image A2, and the third image A3 through the head mounted display HMD.

[0093] At the same time, light from the background passes through the dichroic mirror DM and the head mounted display HMD to reach the user's eyes. Therefore, the user visually recognizes the first image A1, the second image A2, the third image A3, and the fourth image H at different positions in the depth direction as a real aerial scene overlapping the background.

[0094] As described above, in the image display device 200 of the present embodiment, an image projection device S that operates by a signal input from a common image signal input unit includes a first image projection unit S1, a second image projection unit S2, and a third image projection unit S3 for imaging a plurality of images at different positions in the depth direction. Thus, compared with a structure in which the first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 are respectively constituted by separate image display devices and are driven and controlled by separate wiring, space saving and light weight can be achieved. Compared with a structure in which separate image projection devices are respectively assigned to a plurality of images imaged at different positions in the depth direction and are driven and controlled by separate wiring, an increase in the number of components, an increase in the size and weight of the device, and a complication of the device structure can be suppressed. Therefore, the convenience of the image display device that displays in a manner in which the projected image appears to overlap with the background can be improved.

[0095] The image projection device S can be configured to have Fig.11 Specifically, the area between the flat area where the first image projection unit S1 and the third image projection unit S3 are provided and the flat area where the second image projection unit S2 is provided can be configured to have a curved surface.

[0096] The necessity of the area that does not contribute to image projection being flat is lower than the necessity of the area that contributes to image projection being flat. Therefore, in this example, the area that does not contribute to image projection in the image projection device S is configured to be a curved surface. According to such a structure, the occupied space of the image projection device S can be reduced, so the enlargement of the device can be further suppressed.

[0097] In this example, the area that does not contribute to the image projection of the image projection device S is a continuous curved surface. However, depending on the position and size of the area, a structure in which a plurality of planes with different inclination angles are connected or a structure combining a curved surface and a flat surface may be adopted.

[0098] like Fig.12As shown, the image projection device S may include a first flexible cable FC1 and a second flexible cable FC2. The first flexible cable FC1 connects the first image projection unit S1 and the third image projection unit S3 in a communication manner. The second flexible cable FC2 connects the second image projection unit S2 and the third image projection unit S3 in a communication manner. Therefore, by inputting a signal from a common image signal input unit to any one of the first image projection unit S1, the second image projection unit S2, and the third image projection unit S3, it is possible to supply signals to the remaining image projection units to perform image projection operations.

[0099] In this case, the first image projection unit S1, the second image projection unit S2 and the third image projection unit S3 can be respectively composed of a liquid crystal display device with a backlight, a self-luminous organic EL display device or an inorganic EL element, a projector device using a light source and a modulation element, etc.

[0100] In addition, since the first flexible cable FC1 and the second flexible cable FC2 are flexible, the layout freedom of the first image projection unit S1, the second image projection unit S2, and the third image projection unit S3 for obtaining a desired optical system can be improved. In addition, by replacing the area of ​​the image projection device S that does not contribute to image projection with a flexible cable, the device can be made lighter.

[0101] The number, length, shape, etc. of each of the first flexible cables FC1 and the second flexible cables FC2 may be appropriately determined.

[0102] The configuration of the second embodiment described above is merely an example for facilitating understanding of the present invention, and the configuration of the second embodiment can be appropriately changed or improved without departing from the gist of the present invention.

[0103] The number of image projection units included in the image projection device S is not limited to three. It may be two, or may be four or more. Depending on the number of image projection units included in the image projection device S, the number of beam splitters is also appropriately determined.

[0104] exist Figures 10 to 12 In the respective exemplified structures, the positions of the first image A1, the second image A2, the third image A3, and the fourth image H visually recognized by the user are different in the depth direction. However, at least one of the positions of the first image A1, the second image A2, the third image A3, and the fourth image H may be the same as at least one of the other three positions in the depth direction.

[0105] Fig.13 The structure of the image display device 300 according to the third embodiment is exemplified. Figure 1Substantially the same components of the image display device 100 of the example are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0106] By using the image display device 300 , the user visually recognizes the first image A1 , the second image A2 , and the third image H as different positions in the depth direction.

[0107] The image display device 300 includes a light source unit CW. The light source unit CW is a device that emits laser light for projecting the first image A1, the second image A2, and the third image H. As the light source unit CW, for example, a semiconductor laser device including a semiconductor laser element and a control circuit can be used. The wavelength of the laser light emitted from the light source unit CW is not limited as long as it is in the visible light range, and is preferably any one of red, blue, and green. The light emitted from the light source unit CW can be a single color or a mixed color of multiple colors. The light source unit CW can also be configured to emit red, blue, and green light in a time-sharing manner. The light emitted by the light source unit CW can be continuous light or pulsed light. The light source unit CW can also be configured to include a collimating lens and other optical elements. The light source unit CW is equipped with a liquid crystal display element and a DMD (Digital Mirror Device), so that it can emit light including a specified image.

[0108] The image display device 300 includes a first reflector M1, a second reflector M2, a third reflector M3, and a prism Pr. The first reflector M1, the second reflector M2, and the third reflector M3 are respectively substantially flat optical elements that reflect light incident on a reflective surface, and are arranged at an angle of 45 degrees to the vertical direction and the depth direction. The prism Pr is an optical element for introducing light into a light guide of a head mounted display HMD.

[0109] The image display device 300 includes a first lens L1, a second lens L2, and a first semi-transparent mirror HM1. The first lens L1 and the second lens L2 are respectively arranged on the propagation path of the laser emitted from the light source unit CW. The first lens L1 and the second lens L2 are optical elements that focus or amplify the laser. The first lens L1 is arranged between the light source unit CW and the first semi-transparent mirror HM1. The second lens L2 is arranged between the third reflector M3 and the prism Pr. In addition, the number and position of the lenses arranged on the propagation path of the laser can be appropriately determined according to the position of each image formed.

[0110] The first semi-transparent half-reflective mirror HM1 is a roughly flat optical element that reflects a portion of light incident on one surface and transmits the remaining portion. The first semi-transparent half-reflective mirror HM1 is configured in a manner that forms an angle of 45 degrees with respect to the vertical direction and the depth direction. The reflectivity and transmittance of the first semi-transparent half-reflective mirror HM1 can be selected to have an arbitrary balance. For example, the reflectivity and transmittance can be 50% respectively.

[0111] The image display device 300 includes an aperture AP. The aperture AP is an optical element for allowing only light that has reached a limited area to pass through. The aperture AP is disposed between the second lens L2 and the prism Pr. Therefore, the aperture AP limits the diameter of the light that has been focused by the second lens L2 and allows it to be incident on the light incident surface of the prism Pr.

[0112] The laser light emitted from the light source unit CW passes through the first lens L1 and is incident on the first semi-transparent mirror HM1. A portion of the laser light passes through the first semi-transparent mirror HM1 and is directed toward the first reflector M1. The remaining portion of the laser light is reflected by the first semi-transparent mirror HM1 and is directed toward the second reflector M2. The light incident on the first reflector M1 is reflected by the reflection surface and is incident on one surface of the first beam splitter BS1. The light incident on the second reflector M2 is reflected by the reflection surface and is incident on the other surface of the first beam splitter BS1.

[0113] In the present embodiment, the head mounted display HMD includes a flat light guide plate and a second semi-transparent mirror HM2. The second semi-reflective mirror HM2 is formed in the light guide plate. The second semi-transparent mirror HM2 is configured to reflect a portion of the light incident on the prism Pr and propagating in the light guide plate toward the user's eyes. The second semi-reflective mirror HM2 is a roughly flat optical element that reflects a portion of the light incident on one surface and transmits the remaining portion. The reflectivity and transmittance of the second semi-transparent mirror HM2 can be selected to be an arbitrary balance. For example, the reflectivity and transmittance can be 50% respectively.

[0114] The dichroic mirror DM is an optical component that reflects the wavelength of the laser light emitted from the light source CW and transmits light of other wavelengths. The dichroic mirror DM is arranged above the first retro-reflective unit RR1 and the second beam splitter BS2. The dichroic mirror DM is arranged to be inclined at an angle of 45 degrees to the depth direction.

[0115] Reference Fig.14, the operation of a part of the image display device 300 is described. A part of the laser light emitted from the light source unit CW and incident on one surface of the first beam splitter BS1 via the first reflector M1 passes through the first beam splitter BS1 and reaches the third reflector M3. On the other hand, a part of the laser light emitted from the light source unit CW and incident on the other surface of the first beam splitter BS1 via the second reflector M2 is reflected by the first beam splitter BS1 and reaches the third reflector M3. The light reflected by the third reflector M3 passes through the second lens L2 and the aperture AP and is incident on the prism Pr. The light incident on the prism Pr propagates in the prism Pr and the light guide plate of the head-mounted display HMD and reaches the second semi-transparent mirror HM2. The light reflected by the second semi-transparent mirror HM2 is incident on the user's eyes.

[0116] like Fig.14 As shown in the example of the dotted line in FIG. 1 , the light propagating from the second semi-transparent mirror HM2 toward the user's eyes is extended toward the user's eyes by appropriately designing the shape of the second semi-transparent mirror HM2. Therefore, the user visually recognizes the third image H formed behind the head-mounted display HMD. The head-mounted display HMD and the second semi-transparent mirror HM2 are made of a light-transmitting material, so the background in the direction of the extended line of sight can also be visually recognized. The third reflector M3, the second lens L2, the aperture AP, the prism Pr, and the head-mounted display HMD in this example are an example of the first imaging optical unit.

[0117] Reference Fig.15 , the operation of another part of the image display device 300 is described. A portion of the laser light emitted from the light source unit CW and incident on one surface of the first beam splitter BS1 via the first reflector M1 is reflected by the first beam splitter BS1 and reaches the second beam splitter BS2. On the other hand, a portion of the laser light emitted from the light source unit CW and incident on the other surface of the first beam splitter BS1 via the second reflector M2 passes through the first beam splitter BS1 and reaches the second beam splitter BS2.

[0118] A portion of the laser light reaching the second beam splitter BS2 is reflected by the second beam splitter BS2 and heads toward the first retro-reflection unit RR1. A portion of the laser light retro-reflected by the first retro-reflection unit RR1 passes through the second beam splitter BS2 and enters the dichroic mirror DM. Another portion of the laser light reaching the second beam splitter BS2 passes through the second beam splitter BS2 and heads toward the second retro-reflection unit RR2. A portion of the laser light retro-reflected by the second retro-reflection unit RR2 is reflected by the second beam splitter BS2 and enters the dichroic mirror DM.

[0119] The light reflected by the dichroic mirror DM is imaged as a first image A1 and a second image A2 in a space between the head mounted display HMD and the dichroic mirror DM. The light imaged as the first image A1 and the second image A2 passes through the head mounted display HMD and reaches the user's eyes. Therefore, the user visually recognizes the first image A1 and the second image A2 behind the head mounted display HMD. The second beam splitter BS2, the first retro-reflective unit RR1, the second retro-reflective unit RR2, and the dichroic mirror DM in this example are an example of a second imaging optical unit.

[0120] Since both the laser light reflected by the second beam splitter BS2 and the laser light transmitted through the second beam splitter BS2 are imaged by the dichroic mirror DM, it is possible to suppress a decrease in brightness of the first image A1 and the second image A2 formed in the space between the user's eyes and the background.

[0121] exist Fig.13 In FIG. 1 , the propagation path of the laser reflected by the first reflector M1 is indicated by a single-point dashed line, and the propagation path of the laser reflected by the second reflector M2 is indicated by a dotted line. The difference between the optical path length through the first reflector M1 and the optical path length through the second reflector M2 is reflected in the difference between the imaging position of the first image A1 and the imaging position of the second image A2. By inserting a lens or the like in each optical path to change the magnification of one of the lasers, the imaging positions of the first image A1 and the second image A2 can also be made different.

[0122] As a result, the user visually recognizes the first image A1 , the second image A2 , and the third image H, which are located at different positions in the depth direction, as a real aerial scene overlapping the background.

[0123] Fig.16 The real aerial scene displayed by the image display device 300 is exemplified. Fig.13 The x-axis direction, y-axis direction, and z-axis direction in the figure are respectively Fig.13 The left and right directions, up and down directions, and depth directions correspond to each other.

[0124] In this example, laser beams corresponding to circular images are emitted from the light source CW and are imaged as three circular images at different positions in the z direction. The images of circles with a diameter of 2 mm imaged at positions corresponding to the triangles marked with reference numeral A are Fig.13 The image of the circle with a diameter of 0.75 mm formed at the position corresponding to the triangle marked with the reference numeral B corresponds to the second image A2 in FIG. Fig.13 The image of the circle with a diameter of 0.5 mm formed at the position corresponding to the triangle marked with the symbol * corresponds to the first image A1 in FIG. Fig.13In addition, the measurement device used in the experiment can visually recognize it as the background. It can be seen that even if the first image A1, the second image A2, and the third image H, which are the aerial scene, are displayed superimposed on the background, both the background and the aerial scene can be visually recognized well.

[0125] According to the structure involved in the present embodiment described above, even if a single light source unit CW is used, the image projected to the user's eyes can be imaged at multiple different positions in the depth direction. In addition, since the laser light emitted from the light source unit CW and then transmitted through the first beam splitter BS1 and the laser light emitted from the light source unit CW and reflected by the first beam splitter BS1 are provided to different imaging optical systems for imaging, the degree of freedom related to the adjustment of the imaging position can be increased. Therefore, the convenience of the image display device that displays the projected image in a manner that appears to overlap with the background can be improved.

[0126] In addition, the second imaging optical section does not necessarily need to form a plurality of images, that is, one of the first image A1 and the second image A2 may be omitted.

[0127] On the other hand, Fig.17 As shown in the example, the number of images formed by the second imaging optical unit can be increased to three or more. Fig.13 In addition to the illustrated structure, a third half mirror HM3 and a third beam splitter BS3 are further provided.

[0128] The laser light emitted from the light source unit CW passes through the first lens L1 and is incident on the first semi-transparent mirror HM1. A portion of the laser light incident on the first semi-transparent mirror HM1 passes through the first semi-transparent mirror HM1 and is directed toward the third semi-transparent mirror HM3. Another portion of the laser light incident on the first semi-transparent mirror HM1 is reflected by the first semi-transparent mirror HM1 and is directed toward the second mirror M2. A portion of the laser light incident on the third semi-transparent mirror HM3 passes through the third semi-transparent mirror HM3 and is directed toward the first mirror M1. Another portion of the laser light incident on the third semi-transparent mirror HM3 is reflected by the third semi-transparent mirror HM3 and is incident on one surface of the third beam splitter BS3.

[0129] The laser beam reflected by the first reflector M1 is incident on one surface of the first beam splitter BS1. The laser beam reflected by the second reflector M2 is incident on the other surface of the third beam splitter BS3. The laser beam is incident on the other surface of the first beam splitter BS1 through the third beam splitter BS3. The light incident on one surface of the third beam splitter BS3 is also reflected by the third beam splitter BS3 and incident on the other surface of the first beam splitter BS1.

[0130] The laser light after passing through the third semi-transparent and semi-reflective mirror HM3 and the third beam splitter BS3 is imaged as a fourth image A4 through the dichroic mirror DM. The optical path length used to obtain the fourth image A4 is different from the optical path lengths used to obtain the first image A1 and the second image A2, respectively. Therefore, the imaging position of the fourth image A4 is different from the imaging positions of the first image A1 and the second image A2, respectively. In this example, the fourth image A4 is imaged in the space between the first image A1 and the second image A2. Therefore, the user visually recognizes the fourth image A4 through the head-mounted display HMD in front of the first image A1 and behind the second image A2. In addition, as shown in reference Fig.13 As described above, by appropriately disposing optical elements such as lenses on the optical path for obtaining the fourth image A4, the image formation position of the fourth image A4 can also be adjusted.

[0131] Fig.18 Example by Fig.17 Aerial real scene displayed by the exemplary image display device 300. Conditions and references used to obtain the photograph of this image Fig.16 The conditions described are the same.

[0132] In with Fig.18 The image of the circle with a diameter of 1 mm at the position corresponding to the triangle marked with the reference symbol C is Fig.17 Corresponding to the fourth image A4 in .

[0133] By adding other optical paths having at least one of a half mirror and a beam splitter, the number of images imaged by the second imaging optical part can be further increased.

[0134] The configuration according to the third embodiment described above is merely an example for facilitating understanding of the present invention, and the configuration according to the third embodiment can be appropriately changed or improved without departing from the gist of the present invention.

[0135] In the third embodiment, the laser light reflected by the first beam splitter BS1 is used for imaging by the first imaging optical unit, and the laser light transmitted through the first beam splitter BS1 is used for imaging by the second imaging optical unit. However, a structure in which the laser light reflected by the first beam splitter BS1 is used for imaging by the second imaging optical unit, and the laser light transmitted through the first beam splitter BS1 is used for imaging by the first imaging optical unit may also be used.

[0136] Fig.19 The structure of the image display device 400 according to the fourth embodiment is exemplified. Figure 1 Substantially the same components of the image display device 100 of the example are denoted by the same reference numerals, and duplicate descriptions are omitted.

[0137] By using the image display device 400 , the user visually recognizes the first image A1 projected from the first image projection unit S1 and the second image A2 projected from the second image projection unit S2 as being at different positions in the depth direction.

[0138] The image display device 400 includes a first brightness adjustment unit RND1 and a second brightness adjustment unit RND2. The first brightness adjustment unit RND1 is an optical element that controls the brightness of the imaged first image A1 by adjusting the amount of light emitted from the first image projection unit S1. The second brightness adjustment unit RND2 is an optical element that adjusts the amount of light emitted from the second image projection unit S2 and controls the brightness of the imaged second image A2. As each of the first brightness adjustment unit RND1 and the second brightness adjustment unit RND2, for example, a circular variable ND filter, a polarizing plate, etc. can be used. In addition, a structure in which the first image projection unit S1 itself controls the amount of emitted light and functions as the first brightness adjustment unit RND1 can also be adopted. Similarly, a structure in which the second image projection unit S2 itself controls the amount of emitted light and functions as the second brightness adjustment unit RND2 can also be adopted.

[0139] That is, the light reaching the first beam splitter BS1 from the first image projection unit S1 and the second image projection unit S2 is controlled respectively by the first brightness adjustment unit RND1 and the second brightness adjustment unit RND2, thereby controlling the brightness of the first image A1 and the second image A2 imaged in the space between the user's eyes and the background.

[0140] Fig. 20 4 shows a functional configuration of an image display device 400. The image display device 400 includes an imaging optical section 10, a projection section 20, a drive section 30, and a control section 40.

[0141] The imaging optical section 10 includes a first imaging optical section 11 and a second imaging optical section 12. The first imaging optical section 11 is a component for imaging the first image A1 at a predetermined position. Fig.19 In the exemplary structure, the first imaging optical unit 11 includes: optical components included in the first image projection unit S1, a first beam splitter BS1, a second beam splitter BS2, a first retro-reflection unit RR1, a second retro-reflection unit RR2, and a dichroic mirror DM. The second imaging optical unit 12 is an element for imaging the second image A2 at a predetermined position. Fig.19 In the illustrated structure, the second imaging optical unit 12 includes optical components included in the second image projection unit S2 , a first beam splitter BS1 , a second beam splitter BS2 , a first retro-reflective unit RR1 , a second retro-reflective unit RR2 , and a dichroic mirror DM.

[0142] The projection unit 20 includes a first image projection unit S1 and a second image projection unit S2, and is an element for emitting light for projecting a plurality of images. The light emitted from the first image projection unit S1 is imaged as a first image A1 at a position of a first distance from the dichroic mirror DM by the first imaging optical system. The light emitted from the second image projection unit S2 is imaged as a second image A2 at a position of a second distance from the dichroic mirror DM by the second imaging optical unit 12.

[0143] The driving unit 30 includes a first driving unit 31 and a second driving unit 32. The first driving unit 31 is an element that mechanically changes the positions and angles of the first image projection unit S1 and the first imaging optical unit 11, respectively. The second driving unit 32 is an element that mechanically changes the positions and angles of the second image projection unit S2 and the second imaging optical unit 12, respectively. As each of the first driving unit 31 and the second driving unit 32, a known motor or actuator can be used. In addition, in the case where a part of the screen of the display device is used as the first image projection unit S1, a structure that changes the emission position of light by changing the position of the part is also an example of the first driving unit 31. Similarly, in the case where another part of the screen is used as the second image projection unit S2, a structure that changes the emission position of light by changing the position of the other part is also an example of the second driving unit 32.

[0144] The control unit 40 includes an information processing unit 41 , an image processing unit 42 , a brightness balance control unit 43 , and a drive control unit 44 , and is an element that controls the operation of each unit included in the image display device 400 .

[0145] The image processing unit 42 is configured to process information corresponding to each image projected by the projection unit 20 and to send an image signal to the first image projection unit S1 and the second image projection unit S2. The image signal is configured to cause each image projection unit to emit light for projecting an image.

[0146] The brightness balance control unit 43 controls the amount of light emitted from the first image projection unit S1 and the second image projection unit S2 by driving and controlling the first brightness adjustment unit RND1 and the second brightness adjustment unit RND2 to adjust the brightness of the first image A1 and the second image A2.

[0147] The drive control unit 44 is configured to control the operation of the drive unit 30 by sending control signals to the first drive unit 31 and the second drive unit 32. The control signal sent to the first drive unit 31 includes information for controlling the position and angle of at least one of the first image projection unit S1 and the first imaging optical unit 11. The control signal sent to the second drive unit 32 includes information for controlling the position and angle of at least one of the second image projection unit S2 and the second imaging optical unit 12.

[0148] The information processing unit 41 has a processor that processes various information in a prescribed order. The information processing unit 41 controls the operation of the image processing unit 42, the brightness balance control unit 43, and the drive control unit 44 to synchronize the processing of the image signal and the control signal. The function of the processor can be realized by a general-purpose microprocessor that cooperates with a general-purpose memory. Examples of general-purpose microprocessors include CPUs and MPUs. Examples of general-purpose memories include ROMs and RAMs. The function of the processor can also be realized by a part of a dedicated integrated circuit. Examples of dedicated integrated circuits include microcontrollers, FPGAs, ASICs, etc.

[0149] Reference Fig.21 , the relationship between the change of the brightness of the first image A1 and the second image A2 over time and the stereoscopic display based on the DFD stereoscopic illusion is explained. In this figure, the brightness of the first image A1 and the second image A2 is expressed as the shades of gray. Dark colors represent high brightness, and light colors represent low brightness.

[0150] At time point t=t1, a first image A1 with high brightness and a second image A2 with low brightness are formed. In this case, due to the stereoscopic illusion, the user recognizes the image at a position close to the imaging position of the first image A1 with high brightness. As an example, when the relative brightness of the first image A1 is set to 100 and the relative brightness of the second image A2 is set to 0, the position of the two-dimensional image recognized by the user due to the stereoscopic illusion is the imaging position of the first image A1.

[0151] At time point t=t2, the first image A1 and the second image A2 are imaged with the same degree of brightness. In this case, the two-dimensional image recognized by the user due to the stereoscopic illusion is located in the middle of the imaging position of the first image A1 and the imaging position of the second image A2.

[0152] At time t=t3, a low-brightness first image A1 and a high-brightness second image A2 are imaged. In this case, due to the stereoscopic illusion, the user recognizes the image at a position close to the imaging position of the high-brightness second image A2. As an example, when the relative brightness of the first image A1 is set to 0 and the relative brightness of the second image A2 is set to 100, the position of the two-dimensional image recognized by the user due to the stereoscopic illusion is the imaging position of the second image A2.

[0153] In the above description, examples of 100:0, 50:50, and 0:100 are shown as the brightness balance of the first image A1 and the second image A2. Even with other brightness balances, the user recognizes a two-dimensional image at a position intermediate between the imaging position of the first image A1 and the imaging position of the second image A2 due to the stereoscopic illusion. Specifically, if the brightness balance of the first image A1 and the second image A2 is set to a:b, the user recognizes a two-dimensional image based on the stereoscopic illusion at a position where the distance between the imaging position of the first image A1 and the imaging position of the second image A2 in the depth direction is divided by the ratio of a:b.

[0154] The image display device 400 of this embodiment is configured such that the brightness balance control unit 43 changes the brightness balance a:b between the first image A1 and the second image A2 over time. As a result, the user visually recognizes a two-dimensional image based on a stereoscopic illusion at multiple positions between the imaging position of the first image A1 and the imaging position of the second image A2. As a result, the user recognizes a three-dimensional illusion image DFD.

[0155] According to the above configuration, the user can visually recognize the three-dimensional illusion image DFD in front of the background. Therefore, the convenience of the image display device that displays the projected image so that it appears to overlap with the background can be improved.

[0156] The control of the brightness balance by the brightness balance control unit 43 is repeated from 100:0 to 0:100 as one frame. The more steps of the brightness balance a:b in one frame, the more the number of two-dimensional images with stereoscopic illusion in the middle position of the illusion image DFD increases, and a more three-dimensional expression can be performed. In addition, if the time required for one frame is too long, it will be recognized that the two-dimensional image moves only in the depth direction, so the time required for one frame is preferably set to 200 milliseconds or less. In addition, from the perspective of the possibility of stereoscopic illusion, it is preferred that the viewing angle difference between two frames is 7 minutes or less.

[0157] Furthermore, in addition to the display of the stereoscopic illusion image DFD using the brightness balance control unit 43 , the shape of the stereoscopic illusion image DFD to be recognized can be changed by changing the imaging position of at least one of the first image A1 and the second image A2 .

[0158] Specifically, if Fig. 22 As shown in the example, the drive control unit 44 controls the first drive unit 31 and the second drive unit 32, thereby changing the imaging positions of the first image A1 and the second image A2 during the period from time t=0 to time t=Δt. In this example, the imaging position of the first image A1 moves in parallel in the left-right direction, and the imaging position of the second image A2 moves in parallel in the depth direction. However, the imaging positions of both images can be moved in at least one of the left-right direction, the up-down direction, and the depth direction.

[0159] Fig.23 The change in the shape of the illusion image DFD when only the imaging position of the first image A1 moves in parallel in the left-right direction is exemplified. At time t=0, the first image A1 is imaged at a position of a first distance from the dichroic mirror DM in the depth direction, and the second image A2 is imaged at a position of a second distance from the dichroic mirror DM in the depth direction. As described above, the brightness balance control unit 43 changes the brightness balance of the first image A1 and the second image A2 over time, thereby displaying a rectangular illusion image DFD in one frame.

[0160] Afterwards, at time t=Δt, the driving control unit 44 changes the imaging position of the first image A1, and changes the brightness balance of the first image A1 and the second image A2 over time through the brightness balance control unit 43, thereby displaying a deformed rectangular illusion image DFD in one frame. At this time, the user recognizes that the shape of the illusion image DFD has changed during the period from time t=0 to time t=Δt. Therefore, by changing the imaging position of the first image A1 and the second image A2 every time Δt passes, a dynamic image of a stereoscopic illusion image DFD can be provided to the user.

[0161] Here, the time Δt needs to be longer than the time required to depict one frame of the stereoscopic illusion image DFD. On the other hand, in order to allow the user to recognize the illusion image DFD as a dynamic image, the time Δt is preferably set to less than 200 milliseconds. More preferably, by setting the time Δt to a range of 30 to 60 milliseconds, the user can recognize the illusion image DFD as a smooth dynamic image.

[0162] The configuration according to the fourth embodiment described above is merely an example for facilitating understanding of the present invention, and the configuration according to the fourth embodiment can be appropriately changed or improved without departing from the gist of the present invention.

[0163] As the contents constituting a part of the present invention, the contents of Japanese Patent Application No. 2019-220784 filed on December 5, 2019, Japanese Patent Application No. 2019-220785 filed on December 5, 2019, Japanese Patent Application No. 2019-225353 filed on December 13, 2019, and Japanese Patent Application No. 2019-235337 filed on December 25, 2019 are cited.

Claims

1. An image display device, characterized in that: have: a first image projection unit that emits light corresponding to a first image that is projected toward an eye of a user, wherein the first image is visually recognized as a real aerial scene that overlaps with a background; a beam splitter that reflects a portion of the light emitted from the first image projection unit in a first direction and transmits another portion of the light in a second direction; a first retro-reflecting portion, wherein the first retro-reflecting portion retro-reflects the light reflected in the first direction toward the beam splitter; a second retro-reflecting portion, which retro-reflects the light transmitted in the second direction toward the beam splitter; and an imaging optical unit that forms an image corresponding to the incident light in a space disposed between the user's eyes and a background, The beam splitter transmits the light retro-reflected by the first retro-reflective portion toward the imaging optical portion, and reflects the light retro-reflected by the second retro-reflective portion toward the imaging optical portion. The image display device includes a second image projection unit that emits light corresponding to a second image projected toward the user's eyes, wherein the second image is visually recognized as an aerial real scene overlapping with a background at a position different from the first image in a depth direction. The beam splitter reflects a portion of the light emitted from the second image projection unit toward the first direction, and transmits another portion of the light toward the second direction.

2. The image display device according to claim 1, characterized in that The imaging optical section is a dichroic mirror that selectively reflects a wavelength of light emitted from the first image projection section and a wavelength of light emitted from the second image projection section.

3. The image display device according to claim 1, characterized in that The image display device includes a third image projection unit that forms an image of a third image to be projected toward the user's eyes in the space. An imaging position of the third image is different from at least one of an imaging position of the first image and an imaging position of the second image.

4. The image display device according to claim 2, characterized in that: The image display device includes a third image projection unit that forms an image of a third image to be projected toward the user's eyes in the space. An imaging position of the third image is different from at least one of an imaging position of the first image and an imaging position of the second image.

5. The image display device according to any one of claims 1 to 4, characterized in that: The image display device includes a first drive unit configured to change a relative position between the first image projecting unit and the beam splitter.

6. The image display device according to any one of claims 1 to 4, characterized in that: The image display device includes a second driving unit configured to change a relative position between the second image projection unit and the beam splitter.

7. The image display device according to claim 5, characterized in that: The image display device includes a second driving unit configured to change a relative position between the second image projection unit and the beam splitter.

8. An image display device, characterized in that: have: a first image projection unit that is driven by a signal input from the image signal input unit and emits light corresponding to a first image that is projected toward an eye of a user, wherein the first image is visually recognized as a real aerial scene that overlaps with a background; a second image projection unit that is driven by the signal input from the image signal input unit and emits light corresponding to a second image that is projected toward the user's eyes, wherein the second image is visually recognized as an aerial real scene that overlaps with a background at a position different from that of the first image in a depth direction; a beam splitter that reflects a portion of the light emitted from the second image projection unit toward a first direction and transmits a portion of the light emitted from the first image projection unit toward a second direction; a first retro-reflecting portion, wherein the first retro-reflecting portion retro-reflects the light reflected in the first direction toward the beam splitter; a second retro-reflecting portion, which retro-reflects the light transmitted in the second direction toward the beam splitter; and an imaging optical unit that forms an image corresponding to the incident light in a space disposed between the user's eyes and a background; The beam splitter reflects the light from the first image projection section retro-reflected by the second retro-reflection section toward the imaging optical section, and transmits the light from the second image projection section retro-reflected by the first retro-reflection section toward the imaging optical section.

9. The image display device according to claim 8, characterized in that: The first image projection unit is a light emitting area arranged at a first position in the image projection device. The second image projection section is a light emitting region disposed at a second position different from the first position in the image projection device.

10. The image display device according to claim 9, characterized in that: The image projection device includes an EL element having flexibility.

11. The image display device according to claim 8, characterized in that: The first image projection unit and the second image projection unit are connected by a flexible cable.

12. An image display device, characterized in that: have: a light source unit that emits laser light corresponding to an image to be projected toward the user's eyes; a first imaging optical unit that forms an image corresponding to the incident light at a first position in a space between the user's eyes and a background, wherein the first image formed at the first position is visually recognized as an aerial real scene overlapping the background; a second imaging optical unit that forms an image corresponding to the incident light at a second position in the space that is different from the first position, wherein the second image formed at the second position is visually recognized as an aerial real scene overlapping with a background at a position different from the first image in a depth direction; and a first beam splitter that reflects a portion of the laser light toward one of the first imaging optical portion and the second imaging optical portion and transmits another portion of the laser light toward the other of the first imaging optical portion and the second imaging optical portion, The second imaging optical unit comprises: a second beam splitter, the second beam splitter reflecting a portion of the laser light coming from the first beam splitter in a first direction and transmitting another portion of the laser light in a second direction; a first retro-reflecting portion that retro-reflects one of the laser light reflected in the first direction and the laser light transmitted in the second direction toward the second beam splitter; and A second retro-reflecting portion retro-reflects the other of the laser light reflected in the first direction and the laser light transmitted in the second direction toward the second beam splitter.

13. The image display device according to claim 12, characterized in that: The image display device includes a head mounted display worn by the user, The head mounted display includes at least a portion of the first imaging optics.

14. The image display device according to claim 13, characterized in that: The second imaging optical unit comprises: A dichroic mirror is configured to form an image of the laser light transmitted or reflected by the second beam splitter into the image at the second position.

15. The image display device according to any one of claims 12 to 14, characterized in that: have: a first semi-transparent and semi-reflective mirror, wherein the first semi-transparent and semi-reflective mirror transmits a part of the laser light emitted from the light source unit and reflects another part of the laser light; a first reflecting mirror, the first reflecting mirror reflecting one of the light transmitted through the first semi-transparent mirror and the light reflected by the first semi-transparent mirror toward the first surface of the first beam splitter; as well as and a second reflecting mirror that reflects the other of the light that has passed through the first semi-transmissive mirror and the light that has been reflected by the first semi-transmissive mirror toward the second surface of the first beam splitter.

16. An image display device, characterized in that: have: a first image projection unit that emits light corresponding to a first image that is projected toward an eye of a user, wherein the first image is visually recognized as a real aerial scene that overlaps with a background; a second image projection unit that emits light corresponding to a second image projected toward the user's eyes, wherein the second image is visually recognized as an aerial real scene overlapping with a background at a position different from the first image in a depth direction; an imaging optical unit that images the first image at a first position in a space between the user's eyes and a background, and images the second image at a second position in the space that is different from the first position; a beam splitter that reflects a portion of the light emitted from the first image projection unit in a first direction and transmits another portion of the light in a second direction; a first retro-reflecting portion, wherein the first retro-reflecting portion retro-reflects the light reflected in the first direction toward the beam splitter; a second retro-reflecting portion, which retro-reflects the light transmitted in the second direction toward the beam splitter; and A control unit controls the first image projecting unit and the second image projecting unit so that a balance between the brightness of the first image and the brightness of the second image changes over time.

17. The image display device according to claim 16, characterized in that: The image display device includes a drive unit that changes at least one of an imaging position of the first image and an imaging position of the second image.

18. The image display device according to claim 17, characterized in that: The drive unit changes at least one of the first position and the second position in a direction in which the first image and the second image are arranged.

19. The image display device according to claim 17, characterized in that: The drive unit changes at least one of the first position and the second position in a direction intersecting a direction in which the first image and the second image are arranged.

20. The image display device according to any one of claims 16 to 19, characterized in that: have: an imaging optical unit that forms an image corresponding to the incident light in the space, The beam splitter transmits the light retro-reflected by the first retro-reflective portion toward the imaging optical portion, and reflects the light retro-reflected by the second retro-reflective portion toward the imaging optical portion.

21. The image display device according to claim 20, characterized in that: The beam splitter reflects a portion of the light emitted from the second image projection unit toward the first direction, and transmits another portion of the light toward the second direction.

Images