Image display device

Abstract

The image display device (100) comprises: a first image projection unit (11a) which projects a first image (A1); a first beam splitter (12a) which separates the first projection light emitted from the first image projection unit (11a) into a first transmitted light and a first reflected light; a first retro-reflection unit (13a) which allows the first reflected light to be incident on the first beam splitter (12a) as a first retro-reflection light; and a first imaging optical unit (16a) which images the first retro-reflection light transmitted through the first beam splitter (12a).

Description

Technical Field

[0001] The present invention relates to an image display device, and in particular to an image display device that displays images in mid-air. Background Art

[0002] Conventionally, an instrument panel that displays icons by lighting them up is used as a device for displaying various information in a vehicle. As the amount of information to be displayed increases, an image display device is sometimes embedded in the instrument panel, and sometimes the entire instrument panel is composed of an image display device.

[0003] The instrument panel is located below the windshield of the vehicle. When the driver visually recognizes the information displayed on the instrument panel, he needs to move his eyes downward during driving, which is not preferred. Therefore, a head-up display (hereinafter referred to as HUD: Head Up Display) that projects an image onto the windshield is proposed so that the driver can read the information while visually recognizing the front of the vehicle (for example, refer to Patent Document 1). In such a HUD, an optical device that projects the image onto a large area of ​​the windshield is required, and it is desired to miniaturize and lighten the optical device.

[0004] As an image display device that projects light using a small optical device, a head-mounted HUD in the shape of glasses is known (for example, see Patent Document 2). The head-mounted HUD projects an image onto the user's retina by irradiating light emitted from a light source directly to the user's eyes.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2018-118669

[0008] Patent Document 2: Japanese Patent Application No. 2018-528446 Summary of the invention

[0009] Technical problem that the invention aims to solve

[0010] However, in conventional head-mounted HUDs, the display position of images within the field of view is limited, making it difficult to display various information in each area. In addition, the distance of visually recognizable images is also fixed. It is impossible to perform complex displays such as displaying multiple images in the depth direction or changing the display position of visually recognizable images in the air.

[0011] Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide an image display device capable of displaying a plurality of images in the depth direction.

[0012] Technical solutions to the problem

[0013] In order to solve the above-mentioned problems, the image display device of the present invention comprises: a first image projection unit, which projects a first image; a first beam splitter, which separates the first projection light emitted from the first image projection unit into a first transmitted light and a first reflected light; a first regressive reflection unit, which makes the first reflected light enter the first beam splitter as a first regressive light; and a first imaging optical unit, which images the first regressive light after passing through the first beam splitter.

[0014] In such an image display device of the present invention, the first projection light is separated by the first beam splitter into a first reflected light and a first transmitted light, and the first reflected light becomes a first regressed light and is imaged in the first imaging optical part, so that it can be imaged at a position different from the first transmitted light, and multiple images can be displayed in the depth direction.

[0015] In addition, in one embodiment of the present invention, there is: a second image projection unit, which projects a second image; a second beam splitter, which separates the second projection light emitted from the second image projection unit into a second transmitted light and a second reflected light; a second regression reflection unit, which makes the second reflected light enter the second beam splitter as a second regression light; and a second imaging optical unit, which images the second regression light after passing through the second beam splitter.

[0016] In one embodiment of the present invention, the second beam splitter reflects the first transmitted light toward the second imaging optical section, and the first beam splitter reflects the second transmitted light toward the first imaging optical section.

[0017] In one aspect of the present invention, a cylindrical lens is provided between the first beam splitter and the second beam splitter, and the cylindrical lens transmits the first transmitted light and the second transmitted light.

[0018] In one aspect of the present invention, there are provided: a first polarizing plate that polarizes the first projection light in a first direction; and a second polarizing plate that polarizes the second projection light in a second direction orthogonal to the first direction.

[0019] In addition, in one embodiment of the present invention, it is provided with: a third light source unit, which projects a third image; a waveguide unit, which guides the third projection light emitted from the third light source unit; a light emitting unit, which irradiates the third projection light to the outside of the waveguide unit; and a dielectric multilayer film reflector, which reflects the light passing through the first imaging optical unit, and the position of the returned light imaging is different from the position of the third projection light imaging.

[0020] In one aspect of the present invention, a reflector driving unit is provided for rotationally driving the dielectric multilayer reflector.

[0021] In one aspect of the present invention, a unit driving section is provided for changing the relative position of the first imaging optical section and the dielectric multilayer film reflector.

[0022] Effects of the Invention

[0023] The present invention can provide an image display device that can display a plurality of images in the depth direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A is a schematic diagram schematically showing the image display device 100 according to the first embodiment, and is a plan view of the image display device 100 .

[0025] Figure 1 B is a schematic diagram schematically showing the image display device 100 according to the first embodiment, and is a front view of the image display device 100 .

[0026] Figure 2 A is a diagram for explaining an image displayed in mid-air, and is a plan view for explaining the path of light of the first image A1.

[0027] Figure 2 B is a diagram for explaining the display of an image in the air, and is a plan view for explaining the path of light of the second image A2.

[0028] Figure 2 C is a diagram for explaining the display of an image in mid-air, and is a front view showing the appearance of the first image A1.

[0029] Figure 2 D is a diagram for explaining the display of an image in mid-air, and is a front view showing the appearance of the second image A2.

[0030] Figure 3 A is a diagram for explaining how an image is displayed in the air using the transmitted light T1 and T2 that has passed through the beam splitters 12 a and 12 b , and is a plan view for explaining the path of light of the images A1 and A1 ′.

[0031] Figure 3 B is a diagram for explaining how an image is displayed in the air using the transmitted light T1 and T2 that has passed through the beam splitters 12 a and 12 b , and is a plan view for explaining the path of light of the images A2 and A2 ′.

[0032] Figure 3 C is a diagram for explaining how images are displayed in the air using the transmitted light T1 and T2 that have passed through the beam splitters 12 a and 12 b , and is a front view showing the appearance of images A1 and A1 ′.

[0033] Figure 3D is a diagram for explaining how an image is displayed in the air using the transmitted light T1 and T2 that have passed through the beam splitters 12 a and 12 b , and is a front view showing the appearance of images A2 and A2 ′.

[0034] Figure 4 1 and 2 are diagrams schematically showing the overlapping of right-eye images A1 and A2 ′ and the overlapping of left-eye images A2 and A1 ′.

[0035] Figure 5A 1 is a perspective view schematically showing an image display device 200 according to the second embodiment, and shows an example in which the dielectric multilayer film reflector 26 is arranged at a position farther from the light guide plate portion 25 .

[0036] Figure 5B It is a perspective view schematically showing an image display device 200 according to the second embodiment, and is an example in which the dielectric multilayer film reflector 26 is arranged in front of the light guide plate portion 25 .

[0037] Figure 6 A is a schematic representation Figure 5A A top view of the projection of the image in the example shown.

[0038] Figure 6 B is a schematic representation Figure 5A The example image shown is a side view of the projection.

[0039] Figure 7 A is a schematic representation Figure 5B The example images shown are top views of the projections.

[0040] Figure 7 B is a schematic representation Figure 5B The example image shown is a side view of the projection.

[0041] Figure 8 It is a schematic diagram schematically showing an image display device 300 according to the third embodiment. DETAILED DESCRIPTION

[0042] (First Embodiment)

[0043] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying 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 appropriately omitted. Figure 1 A and Figure 1 B is a schematic diagram showing the outline of the image display device 100 according to the present embodiment. Figure 1 A is the top view, Figure 1 B is the main view. Figure 1 A and Figure 1As shown in FIG. 1B , the image display device 100 includes image projection units 11 a and 11 b , beam splitters 12 a and 12 b , retroreflective units 13 a and 13 b , polarizing plates 14 a and 14 b , a cylindrical lens 15 , and imaging lenses 16 a and 16 b .

[0044] The image projection units 11a and 11b are devices that emit light constituting images (first image and second image), and project images for the right eye and the left eye, respectively. Figure 1 A and Figure 1 In B, the irradiation directions of the light from the image projection units 11a and 11b are opposite, and the image projection units 11a and 11b are arranged opposite to each other. The structure of the image projection units 11a and 11b is not limited, and 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 image projection units 11a and 11b can be static images or dynamic images. The images projected by the image projection units 11a and 11b can be the same or different.

[0045] The beam splitters 12a and 12b are components that transmit a portion of the incident light and reflect another portion of the incident light. The beam splitters 12a and 12b may be partially reflective plates having a film for adjusting the reflectivity formed on the surface of a transparent plate. The transmittance and reflectivity of the light in the beam splitters 12a and 12b may be set at an arbitrary balance. In the present embodiment, for example, the transmittance is set to 50% and the reflectivity is set to 50%. The beam splitters 12a and 12b are respectively configured to form an angle of 45 degrees with the optical axis of the light irradiated from the image projection units 11a and 11b, and the beam splitters 12a and 12b are configured orthogonally to each other. In the present embodiment, an example is shown in which the inclination angle of the beam splitters 12a and 12b is 45 degrees and the beam splitters 12a and 12b are orthogonal to each other, but the beam splitters 12a and 12b may also be configured at an appropriate angle according to the relationship between the light irradiation direction from the image projection units 11a and 11b and the imaging position of the image.

[0046] The retro-reflective parts 13a and 13b are optical components that reflect the incident light in the direction opposite to the incident direction while maintaining the light-collecting property. The retro-reflective parts 13a and 13b may be retro-reflective plates such as a structure in which tiny glass beads are spread on the surface side of the reflective film or a prism. The retro-reflective parts 13a and 13b may be independent retro-reflective plates or may share a single retro-reflective plate.

[0047] Polarizers 14a and 14b are respectively arranged between image projection units 11a and 11b and beam splitters 12a and 12b, and are polarizers that determine the polarization direction of light emitted from image projection units 11a and 11b. The polarization directions of polarizers 14a and 14b are respectively orthogonal, for example, polarizer 14a polarizes light in a direction perpendicular to the plane of the drawing, and polarizer 14b polarizes light in the up-and-down direction in the drawing.

[0048] The cylindrical lens 15 is an optical component that transmits light incident from one side and focuses the light on the opposite side. Figure 1 A and Figure 1 As shown in B, the cylindrical lens 15 is arranged at the center of the image display device 100 so as to be perpendicular to the optical axis of the light emitted from the image projection units 11 a and 11 b.

[0049] The imaging lenses 16 a and 16 b are optical components for imaging the light incident from the beam splitters 12 a and 12 b at predetermined positions in space, and correspond to the imaging optical section in the present invention.

[0050] exist Figure 1 In A, the solid lines drawn from the image projection units 11a, 11b to the beam splitters 12a, 12b represent the paths of the projection light of the images irradiated by the image projection units 11a, 11b. The solid lines drawn from the beam splitters 12a, 12b to the retro-reflection units 13a, 13b represent the paths of the reflected light after being reflected by the beam splitters 12a, 12b and the regressive light after being reflected by the retro-reflection units 13a, 13b. The solid lines from the beam splitters 12a, 12b through the imaging lenses 16a, 16b represent the paths of the transmitted regressive light that passes through the beam splitters 12a, 12b.

[0051] The dotted lines from the beam splitters 12a and 12b to the beam splitters 12b and 12a on the opposite side via the cylindrical lens 15 represent the paths of the transmitted light after passing through the beam splitters 12a and 12b. The dotted lines from the beam splitters 12a and 12b through the imaging lenses 16a and 16b represent the paths of the transmitted and reflected light after being reflected by the beam splitters 12a and 12b.

[0052] like Figure 1 A and Figure 1 As shown in B, the projection light emitted from the image projection units 11a and 11b travels as reflected light, regressed light, transmitted light, transmitted regressed light, and transmitted reflected light, and is formed into images A1, A2, A1', and A2' at predetermined positions in space. Figure 1 A and Figure 1 In the example shown in B, images A1 and A2' are overlapped and displayed on the right eye side, and images A2 and A1' are overlapped and displayed on the left eye side.

[0053] Figure 2 A. Figure 2 B. Figure 2 C. Figure 2 D is a diagram for explaining the display of an image in the air. Figure 2 A is a plan view illustrating the path of light in image A1. Figure 2 B is a top view illustrating the path of light in image A2. Figure 2 C is a front view showing the appearance of image A1. Figure 2 D is a front view showing the appearance of image A2. Figure 1 A and Figure 1 B shows the light path including the expansion of light, but Figure 2 A to Figure 2 In D, for simplicity, the traveling direction is indicated only by lines and arrows. In addition, illustration and description of components that are not necessary for the description of the optical path are omitted.

[0054] like Figure 2 As shown in Figure A, the projection light S1 (first projection light) emitted from the image projection unit 11a (first image projection unit) travels toward the beam splitter 12a (first beam splitter) and is incident on one surface of the beam splitter 12a. A portion of the projection light S1 is reflected by the beam splitter 12a and travels toward the regression reflection unit 13a (first regression reflection unit) as the reflected light R1 (first reflected light), and another portion of the projection light S1 passes through the beam splitter 12a and travels toward the extension direction of the projection light S1 as the transmitted light T1 (first transmitted light). After reaching the regression reflection unit 13a as the first regression light, the reflected light R1 is reflected by the regression reflection unit 13a in the opposite direction of the incident direction. After reaching the beam splitter 12a again, the regression reflected light RR1 passes through the beam splitter 12a and is imaged as the transmitted regression light RR1' in space via the imaging lens 16a (first imaging optical unit) as an image A1. In addition, in the present embodiment, the reflected light R1 (first reflected light) reflected by the beam splitter 12a travels toward the retro-reflection portion 13a (first retro-reflection portion), but the traveling direction of the reflected light R1 is not limited to the direction toward the retro-reflection portion 13a. Other optical components may be arranged between the beam splitter 12a and the retro-reflection portion 13a, and the reflected light R1 may finally reach the retro-reflection portion 13a.

[0055] Likewise, Figure 2As shown in FIG. 1B , the projection light S2 (second projection light) emitted from the image projection unit 11b (second image projection unit) travels toward the beam splitter 12b (second beam splitter) and is incident on one surface of the beam splitter 12b. A portion of the projection light S2 is reflected by the beam splitter 12b and travels toward the regressive reflection unit 13b (second regressive reflection unit) as the reflected light R2 (second reflected light), and another portion of the projection light S2 passes through the beam splitter 12b and travels toward the extension direction of the projection light S2 as the transmitted light T2 (second transmitted light). The reflected light R2 that reaches the regressive reflection unit 13b as the second regressive light is reflected by the regressive reflection unit 13b as the regressive reflected light RR2 in the opposite direction of the incident direction. After the regressive reflected light RR2 reaches the beam splitter 12b again, it passes through the beam splitter 12b and is imaged as the transmitted regressive light RR2' in space via the imaging lens 16b (second imaging optical unit) as the image A2.

[0056] like Figure 2 C and Figure 2 As shown in FIG. 2 , the image A1 is formed on the right eye side by the projection light S1 emitted from the image projection unit 11a, and the image A2 is formed on the left eye side by the projection light S2 emitted from the image projection unit 11b. Here, if the imaging lenses 16a and 16b are not configured, and the components are configured so that the optical path lengths of the projection light S1 and S2, the reflected light R1 and R2, the return light RR1 and RR2, and the transmitted return light RR1' and RR2' before the images A1 and A2 are formed are equal, the images A1 and A2 are visually recognized as the same position in the air on the right eye side and the left eye side. On the contrary, if the emission position of the projection light S1 and S2 is moved in the up-down direction in the figure so that the optical path lengths are different, the images A1 and A2 are visually recognized as different positions in the air on the right eye side and the left eye side. In addition, by moving the positions of the imaging lenses 16a and 16b in the up-down direction in the figure, the images A1 and A2 are also visually recognized as different positions in the air on the right eye side and the left eye side.

[0057] Figure 3 A. Figure 3 B. Figure 3 C and Figure 3 D is a diagram for explaining how an image is displayed in the air using the transmitted light T1 and T2 that have passed through the beam splitters 12 a and 12 b. Figure 3 A is a top view illustrating the path of light of images A1 and A1 ′. Figure 3 B is a top view illustrating the path of light of images A2 and A2'. Figure 3 C is a front view showing the appearance of images A1 and A1'. Figure 3 D is a front view showing the appearance of images A2 and A2'.

[0058] like Figure 3As shown in A, the transmitted light T1 of the projection light S1 emitted from the image projection unit 11a after passing through the beam splitter 12a enters the beam splitter 12b via the cylindrical lens 15 and is reflected as the transmitted reflected light TR1. The transmitted reflected light TR1 is imaged as the image A1' in space via the imaging lens 16b. At this time, since the polarizing plate 14a (first polarizing plate) is arranged between the image projection unit 11a and the beam splitter 12a, the polarization directions (first direction) of the images A1 and A1' are the same. In addition, since the image A1' is imaged via the cylindrical lens 15 and the optical path length from the image projection unit 11a is different, the images A1 and A1' are visually recognized as different depths on the right eye side and the left eye side. Both images A1 and A1' are emitted from the image projection unit 11a, the display contents are the same, and the images themselves are reversed.

[0059] Likewise, if Figure 3 As shown in FIG. 1B , the transmitted light T2 of the projection light S2 emitted from the image projection unit 11b that passes through the beam splitter 12b is incident on the beam splitter 12a via the cylindrical lens 15 and is reflected as the transmitted reflected light TR2. The transmitted reflected light TR2 is imaged as the image A2' in space via the imaging lens 16a. At this time, since the polarizing plate 14b (second polarizing plate) is arranged between the image projection unit 11b and the beam splitter 12b, the polarization directions (second direction) of the images A2 and A2' are the same. In addition, since the polarization directions of the polarizing plates 14a and 14b are orthogonal to each other, the polarization directions of the images A1, A1' and the images A2, A2' are also orthogonal to each other. In addition, since the image A2' is displayed via the cylindrical lens 15 and the optical path length from the image projection unit 11b is different, the images A2' and A2 are visually recognized as different depths on the right eye side and the left eye side. The images A2 and A2' are both projected from the image projection unit 11b, have the same display content, and are inverted.

[0060] Figure 4 Schematically shows the overlap of right-eye image A1 and A2' and the overlap of left-eye image A2 and A1'. Figure 3 A to Figure 3 In the example of polarizing plates 14a and 14b shown in D, the image A1 polarized in the vertical direction in the figure and the image A2' polarized in the horizontal direction in the figure can be visually recognized at different depths while overlapping each other on the right eye side. In addition, the image A2 polarized in the horizontal direction in the figure and the image A1' polarized in the vertical direction in the figure can be visually recognized at different depths while overlapping each other on the left eye side.

[0061] Thus, the polarizing plates 14a and 14b are polarization direction switching mechanisms, and by placing other polarizing plates in front of the user's eyes, images A1 and A2' and images A2 and A1' can be selectively displayed. In addition, since light with different polarization directions can be blocked, noise light can be removed and noise of the image formed in the air can be removed.

[0062] exist Figure 1 A. Figure 1 B and Figure 3 A to Figure 3 In D, an example is shown in which images A1, A2', A2, A1' are displayed on the right eye side and the left eye side, but a light shielding plate or the like may be arranged on either of the imaging lenses 16a and 16b to overlap the two images only on the other eye side. In addition, a reflector may be combined with the cylindrical lens 15 to reflect the transmitted light T1 or T2 again toward the cylindrical lens 15, so that images A1, A1' or A2, A2' are formed on one eye side.

[0063] As described above, in the image display device 100 of the present embodiment, since the projection lights S1 and S2 are separated into reflected lights R1 and R2 and transmitted lights T1 and T2 by the beam splitters 12a and 12b, the reflected lights R1 and R2 become regressive lights RR1 and RR2 and are imaged by the imaging lenses 16a and 16b, it is possible to display images A1 and A2 at positions different from images A1' and A2', and multiple images can be displayed in the depth direction.

[0064] (Second Embodiment)

[0065] Next, use Figure 5A to Figure 7 B. A second embodiment of the present invention will be described. The description of the contents overlapping with the first embodiment will be omitted. Figure 5A and Figure 5B It is a perspective view schematically showing an image display device 200 according to the present embodiment. Figure 5A This is an example in which the dielectric multilayer film reflector 26 is arranged at a position farther than the light guide plate portion 25 . Figure 5B This is an example in which the dielectric multilayer film reflector 26 is arranged in front of the light guide plate portion 25 .

[0066] like Figure 5A as well as Figure 5B As shown, the image display device 200 of this embodiment includes a unit driving unit 110, a light source unit 21 (third light source unit), an optical fiber unit 22, a lens 23, a prism 24, a light guide plate unit 25 (waveguide unit), and a dielectric multilayer film reflector 26.

[0067] The unit driving unit 110 is a device including a projection unit and a driving unit for moving the projection unit three-dimensionally. The projection unit includes a light source and an optical system for displaying an image in space. The structure of the unit driving unit 110 is not limited. For example, a driving unit such as a motor may be housed in a frame, and the image display device 100 shown in the first embodiment may be used as a projection unit. Figure 5A and Figure 5B As shown, the unit driving section 110 is disposed above the light guide plate section 25 and the dielectric multilayer film reflector 26 , and is configured to irradiate the dielectric multilayer film reflector 26 with light.

[0068] The light source unit 21 is a component that has a semiconductor laser element and a package and emits light of a specified wavelength. The light source unit 21 projects an image (third image). The specific structure of the light source unit 21 is not limited, and a well-known CAN type or frame type package can be used. SHG (Second Harmonic Generation) elements or the like can also be mounted on the light source unit 21 to perform wavelength conversion. The wavelengths of the light emitted by the light source unit 21 can be the same or different.

[0069] The optical fiber unit 22 is an optical element that guides the light (third projection light) emitted from the light source unit 21 and is composed of a flexible optical fiber. The incident end face of the optical fiber unit 22 is arranged opposite to the light source unit 21, and the emission end face of the optical fiber unit 22 is arranged opposite to the lens 23.

[0070] The lens 23 is an optical element for adjusting the diffusion angle of the light emitted from the optical fiber unit 22 to allow the light to enter the prism 24 and the light incident portion of the light guide plate unit 25. The lens 23 may be a collimator lens.

[0071] The prism 24 is an optical element having a triangular cross section and disposed near the light incident portion of the incident light in the light guide plate portion 25. A gap is provided between the light guide plate portion 25 and the prism 24. The material constituting the prism 24 is not limited, but in order to allow the light from the light source portion 21 to be incident on the light guide plate portion 25 efficiently, the refractive index of the prism 24 is preferably at the same level as the refractive index of the light guide plate portion 25, and the prism 24 is preferably made of the same material as the light guide plate portion 25.

[0072] The light guide plate portion 25 is a flat plate-shaped member made of a light-transmitting material, and can be seen through from one side to the other side. The prism 24 is arranged on one end side of the light guide plate portion 25 in a manner close to the light incident portion. In addition, the light guide plate portion 25 has a light emitting portion such as a semi-transparent mirror or a hologram formed inside the side opposite to the prism 24. Therefore, in the light guide plate portion 25, the light traveling inside is emitted toward the user's eyes, and the light traveling from the side opposite to the user is transmitted.

[0073] The dielectric multilayer film reflector 26 is a plate-shaped component having a multilayer film formed by repeatedly stacking dielectrics with different refractive indices. The dielectric multilayer film reflector 26 is an optical component that reflects light of a specified wavelength and transmits light of other wavelengths according to the film thickness of the dielectric layer. Figure 5A and Figure 5B Although not shown in the figure, a reflector driving unit for rotationally driving the angle of the reflective surface is mounted on the dielectric multilayer reflector 26 . The reflector driving unit can switch the reflection direction of light according to a control signal.

[0074] Figure 6 A and Figure 6 B is a schematic representation Figure 5A A diagram of the projection of an image in the example shown. Figure 6 A is the top view, Figure 6 B is a side view. Figure 7 A and Figure 7 B is a schematic representation Figure 5B A diagram of the projection of an image in the example shown. Figure 7 A is the top view, Figure 7 B is a side view. Figure 6 A and Figure 6 B shows an example of controlling the angle of the dielectric multilayer film reflector 26 so that the images A1 and A2' are displayed farther than the light guide plate portion 25. Figure 7 A and Figure 7 B shows an example in which the angle of the dielectric multilayer film reflector 26 is controlled so that the images A2 and A1 ′ are displayed closer to the front than the light guide plate portion 25 .

[0075] like Figure 6 A and Figure 7 As shown in FIG. 1A , in the image display device 200 of the present embodiment, light emitted by the light source unit 21 is incident on the incident end face of the optical fiber unit 22 and is incident on the light guide plate unit 25 from the exit end face of the optical fiber unit 22 via the lens 23 and the prism 24. The light is repeatedly reflected inside the light guide plate unit 25 and reaches the light exiting unit, and is irradiated to the user side (projection direction) as exiting light and displayed as an image H in the air, and is visually recognized by overlapping with the background that passes through the light guide plate unit 25.

[0076] like Figure 6 B and Figure 7As shown in FIG. 1B , light is irradiated from the unit driving unit 110 toward the dielectric multilayer film reflector 26 located below the unit driving unit 110, and the light is irradiated in a direction corresponding to the inclination angle of the dielectric multilayer film reflector 26, and images A1, A2' and images A2, A1' are displayed. Here, when the image display device 100 of the first embodiment is used as a projection unit accommodated in the unit driving unit 110, the display positions of the images A1, A2' and images A2, A1' in the air are the same as those of the image display device 100 of the first embodiment. Figure 1 A and Figure 1 B. Therefore, the image H projected from the light source unit 21 overlaps with the images A1 and A2' and the images A2 and A1' displayed by the unit driving unit 110 and is displayed at positions with different depths.

[0077] If the position of the projection unit (image display device 100) is moved three-dimensionally in the unit driving unit 110, the path and optical path length of the emitted light change, so the positions of the displayed images A1, A2' and images A2, A1' also change. Thus, the relative positions of images A1, A2', A2, A1' with respect to the image H and the background can also be changed for display.

[0078] like Figure 6 A. Figure 6 B. Figure 7 A and Figure 7 As shown in FIG. 2B , by arranging a polarizing plate P for selecting the polarization direction of light transmitted in front of the user's eyes, it is possible to select which of images A1 and A2 ′ and images A2 and A1 ′ formed in the air is visually recognized by the user.

[0079] exist Figure 6 A. Figure 6 B. Figure 7 A and Figure 7 B shows examples corresponding to the right eye side and the left eye side, respectively, but it can also be either the right eye side or the left eye side. Even when the dielectric multilayer film reflector 26 is arranged on either the far side or the near side of the light guide plate portion 25, the imaging position of the images A1, A2, A1', A2' can be switched by switching the tilt angle.

[0080] As described above, in the image display device 200 of this embodiment, the image H projected by the light source unit 21 can be overlapped with the images A1, A2, A1', and A2' projected from the unit driving unit 110, and multiple images can be formed in the depth direction. The imaging positions of A1, A2, A1', and A2' formed in space can also be changed.

[0081] (Third Embodiment)

[0082] Next, use Figure 8 A third embodiment of the present invention will be described, and descriptions of contents overlapping with those of the first embodiment will be omitted. Figure 8 Schematic diagram showing the outline of the image display device 300 according to the present embodiment. Figure 8 As shown, the image display device 300 includes image projection units 31a, 31b, beam splitters 32a, 32b, retro-reflective units 33a, 33b, light guide plate units 34a, 34b, a cylindrical lens 35, lenses 36a, 36b, prisms 37a, 37b, and reflection mirrors 38a, 38b.

[0083] In the image display device 300 of the present embodiment, the projection light emitted from the image projection units 31a and 31b is incident on the light guide plate units 34a and 34b via the lenses 36a and 36 and the prisms 37a and 37b. The light is repeatedly reflected inside the light guide plate units 34a and 34b and is incident on the beam splitters 32a and 32b. A part of the light is reflected by the beam splitters 32a and 32b and travels toward the retro-reflection units 33a and 33b in the light guide plate units 34a and 34b, and a part of the light passes through the beam splitter 32a and travels toward the cylindrical lens 35. The light reaching the retro-reflection units 33a and 33b is reflected in the direction opposite to the incident direction and is incident on the beam splitters 32a and 32b again and passes through them, and then is reflected by the reflectors 38a and 38b to form images A1 and A2.

[0084] Furthermore, the light that has passed through the beam splitters 32 a and 32 b and reached the cylindrical lens 35 is reflected by the reflection mirrors 38 b and 38 a on the opposite side and is formed into images A2 ′ and A1 ′.

[0085] In this embodiment, since the projection light is separated into reflected light and transmitted light by the beam splitters 32a and 32b, and the reflected light becomes regressive light and forms an image, the image display device 300 can display images A1 and A2 at positions different from those of images A1' and A2', and can form multiple images in the depth direction. By using a scheme of repeated reflection inside the light guide plate parts 34a and 34b, the image display device 300 can be made thinner and lighter.

[0086] The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0087] This application claims the priority based on Japanese Application No. 2019-105128 filed on June 5, 2019, and all the contents described in the Japanese Application are cited.

Claims

1. An image display device, characterized in that: have: a first image projecting unit, the first image projecting unit projecting a first image; a first beam splitter for separating first projection light emitted from the first image projection unit into first transmitted light and first reflected light; a first retro-reflecting portion, the first retro-reflecting portion causing the first reflected light to be incident on the first beam splitter as first retro-reflecting light; as well as a first imaging optical unit, wherein the first imaging optical unit images the first returning light after passing through the first beam splitter, and The image display device further comprises: a second image projecting unit, the second image projecting unit projecting a second image; a second beam splitter for separating the second projection light emitted from the second image projection unit into a second transmitted light and a second reflected light; a second retro-reflecting portion, the second retro-reflecting portion causing the second reflected light to be incident on the second beam splitter as second retro-reflecting light; as well as The second imaging optical unit is used to image the second returning light after passing through the second beam splitter.

2. The image display device according to claim 1, characterized in that the second beam splitter reflects the first transmitted light toward the second imaging optical part, The first beam splitter reflects the second transmitted light toward the first imaging optics.

3. The image display device according to claim 2, characterized in that A cylindrical lens is provided between the first beam splitter and the second beam splitter, The cylindrical lens transmits the first transmitted light and the second transmitted light.

4. The image display device according to claim 1, characterized in that have: a first polarizer that polarizes the first projection light in a first direction; and A second polarizer is provided, wherein the second polarizer polarizes the second projection light in a second direction orthogonal to the first direction.

5. The image display device according to claim 2, characterized in that: have: a first polarizer that polarizes the first projection light in a first direction; and A second polarizer is provided, wherein the second polarizer polarizes the second projection light in a second direction orthogonal to the first direction.

6. The image display device according to claim 3, characterized in that: have: a first polarizer that polarizes the first projection light in a first direction; and A second polarizer is provided, wherein the second polarizer polarizes the second projection light in a second direction orthogonal to the first direction.

7. The image display device according to any one of claims 1 to 6, characterized in that: have: a third light source unit, the third light source unit projecting a third image; a waveguide portion for guiding the third projection light emitted from the third light source portion; a light emitting portion, the light emitting portion irradiating the third projection light to the outside of the waveguide portion; as well as a dielectric multilayer film reflector that reflects light that has passed through the first imaging optical section, The position of the returning light imaging is different from the position of the third projection light imaging.

8. The image display device according to claim 7, characterized in that: A reflector driving unit is provided for rotationally driving the dielectric multilayer reflector.

9. The image display device according to claim 7, characterized in that: A unit driving section is provided for changing the relative position between the first imaging optical section and the dielectric multilayer film reflector.

10. The image display device according to claim 8, characterized in that A unit driving section is provided for changing the relative position between the first imaging optical section and the dielectric multilayer film reflector.

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