Display device, vehicle, display system, mobile body, and image display unit storage device

Abstract

A display device according to the present disclosure comprises: a first display unit comprising a first image display unit for displaying a first image and a first optical system for forming a first formed image of the first image; and a second display unit comprising a second image display unit for displaying a second image. The first and second display units are disposed such that the optical paths thereof intersect.

Description

Display device, vehicle, display system, moving body, and image display unit housing device

[0001] The present invention relates to a display device that shows an image of an image to a user, a vehicle, a display system, and a moving body including the same. The present invention also relates to an image display unit housing device.

[0002] A display device that forms a real image of an image on a screen and shows the real image to the user, and a virtual image display device that forms a virtual image of an image and shows the virtual image to the user are known (for example, Patent Document 1).

[0003] Japanese Patent No. 7528348

[0004] The display device of the present disclosure includes a first display unit including a first image display unit that displays a first image and a first optical system that forms a first conjugate image of the first image, and a second display unit including a second image display unit that displays a second image. The first and second display units are arranged such that their optical paths intersect. The vehicle, display system, and moving body of the present disclosure include the above display device. The image display unit housing device of the present disclosure is a device in which the display unit can be installed.

[0005] The above and other objects, features, and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

[0006] This is a schematic diagram illustrating the configuration of the display device in the first embodiment. This is a schematic diagram illustrating the display unit of the first embodiment used in the display device. This is a schematic diagram illustrating the display unit of the second embodiment used in the display device. This is a schematic diagram illustrating the display unit of the third embodiment used in the display device. This is a diagram illustrating the display device mounted on a vehicle. This is a diagram illustrating the display device mounted on a vehicle as an RSE. This is a block diagram illustrating the configuration of the display device in the second embodiment. This is a block diagram illustrating the configuration of the display device in the third embodiment. This is a schematic diagram illustrating the configuration of the display device in the fourth embodiment. As an example, this is a schematic diagram showing a display device using the display unit of the fourth embodiment. As yet another example, this is a schematic diagram showing a display device using the display unit of the fourth embodiment. As an example, this is a schematic diagram showing a display device using the display unit of the fifth embodiment. As yet another example, this is a schematic diagram showing a display device using the display unit of the sixth embodiment. As an example, this is a schematic diagram showing a display device using the display units of the fifth and sixth embodiments. As yet another example, this is a schematic diagram showing a display device using the display units of the fifth and sixth embodiments.

[0007] Hereinafter, one or more embodiments of the present invention will be described with reference to the drawings. However, the scope of the invention is not limited to the disclosed embodiments. In each figure, components denoted by the same reference numerals are identified as identical components, and their descriptions are omitted where appropriate. In this specification, general reference numerals are used without subscripts, while individual components are indicated by subscripts.

[0008] Conventionally, there has been a desire to improve the design flexibility of display devices equipped with multiple display units. Therefore, the display device according to this embodiment comprises a plurality of two first and second display units. The first display unit comprises a first image display unit that displays a first image and a first optical system that forms a first image of the first image. The second display unit comprises a second image display unit that displays a second image. The first and second display units are arranged so that their respective optical paths intersect. When forming multiple images, the display device will have a separate display unit for each individual image. Such a display device can satisfy the above requirements. Hereinafter, such a display device will be described in more detail with respect to several embodiments.

[0009] (First Embodiment) Figure 1 is a schematic diagram illustrating the configuration of the display device in the embodiment. The upper part of Figure 1 is a cross-sectional view. The lower part of Figure 1 is an external perspective view. Figure 2 is a schematic diagram illustrating a first-mode display unit used in the display device. Figure 3 is a schematic diagram illustrating a second-mode display unit used in the display device. Figure 4 is a schematic diagram illustrating a third-mode display unit used in the display device. In Figures 2 to 4, the upper parts are cross-sectional views. The lower parts are diagrams illustrating the optical path and polarization state of the optical system. Figure 5 is a diagram illustrating the display device mounted on a vehicle. The upper part of Figure 5 is an overall schematic diagram of the vehicle, and the lower part of Figure 5 is a schematic diagram of the front part of the vehicle interior. Figure 6 is a diagram illustrating the display device mounted on a vehicle as an RSE.

[0010] A display device in one embodiment of this disclosure may be a non-wearable device for the viewer. That is, the display device may not be worn by the viewer but may be fixed to the environment. For example, the display device may be fixed to a wall, column or ceiling, etc. Alternatively, the display device may be fixed to the interior of a vehicle. This disclosure may also be worn by the viewer. If worn by the viewer, the display device may be provided with a mounting part (not shown) so that the viewing window is fixed at the position of the viewer's eyes.

[0011] The display device 1000a in the first embodiment comprises a plurality of two first and second display units 10a and 10b, and a housing HSA that houses these first and second display units 10a and 10b. The first and second display units 10a and 10b are arranged so that their respective optical paths LPa and LPb intersect. In the example shown in Figure 1, the intersection angle is 90°, but the intersection angle is not limited to 90° and only requires that the optical paths LPa and LPb intersect. More specifically, the housing HSA may be a hollow member having a substantially rectangular parallelepiped shape. The first display unit 10a is located on a first inner surface (e.g., the bottom surface) WL1 inside the housing and is housed in the housing HSA. The second display unit 10b is located on a second inner surface (e.g., the left side when viewing the paper from the front) WL2 adjacent to the first inner surface WL1 and is housed in the housing HSA. The housing HSA comprises six plate-shaped first to sixth members MB1 to MB6. The first member MB1 forms the first inner surface WL1. The second member MB1 forms the second inner surface WL2. The third member MB3 forms a third inner surface (e.g., the top surface) WL3 opposite to the first inner surface WL1. The fourth member MB4 forms a fourth inner surface (e.g., the right side when the paper is viewed from the front) WL4 opposite to the second inner surface WL2. Each of these first to fourth members MB1 to MB4 may be a substantially rectangular plate-shaped member and may be identical in shape to one another. The first to fourth members MB1 to MB4 may be sequentially connected and fixed along their edges to form a cylindrical body with a right-angled quadrilateral cross-section. The fifth member MB5 is a substantially square plate-shaped member and may be fixed to the cylindrical body so as to close one of the openings of the cylindrical body. The sixth member MB6 may be a substantially square plate-shaped member and may be fixed to the cylindrical body so as to close the other opening of the cylindrical body. The third member MB3 has a substantially rectangular through-opening formed as a first viewing window WDa for viewing the image (first image) formed by the first display unit 10a. The first window member WMa may be fitted and fixed into the first viewing window WDa. The fourth member MB4 may have a substantially rectangular through-opening formed as a second viewing window WDb for viewing the image (second image) formed by the second display unit 10b. The second window member WMb may be fitted and fixed into the second viewing window WDb.These first and second window members WMa and WMb are made of a material that transmits visible light. Such materials include, for example, polycarbonate resin and acrylic resin. At least one of the first and second window members WMa and WMb may be omitted. In other words, the viewing window WD may or may not have a window member. The viewing window may function as a viewing section. As described above, the first and second display units 10a and 10b are arranged so that the optical path LPa of the first display unit 10a and the optical path LPb of the second display unit 10b intersect at point PS1 orthogonal. Therefore, the display device 1000a can share the space formed by such a single rectangular parallelepiped housing HSA between the two first and second display units 10a and 10b, and can form two images with one unit.

[0012] Here, "facing" in this context means that they are opposite each other. When A faces B, other members may or may not be interposed between member A and member B. In other words, when member A faces member B, in this context, member A is interpreted as being located on one side of member B.

[0013] Since the first and second display units 10a and 10b have the same configuration, they will be described together as the display unit 10 of the first embodiment below.

[0014] The display unit 10 includes, for example, an image display unit 11 and an optical system 12, as shown in Figure 2.

[0015] The image display unit 11 is a device having a display surface 111 on which it displays an image of visible light. The image may be a still image or a moving image. The image display unit 11 may display an image of first linear polarization. For example, a polarizing plate may be placed in front of the display surface 111. The first linear polarization may be S-polarization or P-polarization perpendicular to S-polarization. In this embodiment, the first linear polarization is S-polarization as an example, and the second linear polarization is P-polarization as an example, but it is not limited to this. For example, in the following description, S-wave polarization may be read as P-wave polarization, and P-wave polarization may be read as S-wave polarization. The image display unit 11 may be, for example, a liquid crystal display device (LCD). Alternatively, for example, the image display unit 11 may be an organic electroluminescent display device (OLED).

[0016] The image display unit 11 may include an illuminator that illuminates the display surface 111 in a planar manner. The illuminator is also called a backlight. The illuminator may be an edge-lit backlight or a direct-lit backlight. The light source of the illuminator may be a cold cathode fluorescent lamp, a halogen lamp, or a xenon lamp, or it may be a light-emitting diode (LED), an organic light-emitting diode (OLED), a semiconductor laser (LD), etc. The image display unit 11 is not limited to a liquid crystal display device (LCD) including a liquid crystal panel (transmissive display panel). The image display unit 11 may be a self-emissive image display unit 11 including, for example, a light-emitting diode (LED), an organic light-emitting diode (OLED), a semiconductor laser (LD), etc.

[0017] The optical system 12 forms an image (image-formed image) of the image displayed on the image display unit 11. The image can be a real image or a virtual image. In the example shown in Figure 2, the optical system 12 comprises a first phase difference plate 13, a semi-transparent mirror 14, a second phase difference plate 15, and a reflective polarizer 16. These optical elements 13 to 16 are arranged sequentially in this order with respect to the display surface 111 of the image display unit 11, moving away from the display surface 111.

[0018] The first phase difference plate 13 is an optical element that emits light with a phase difference between mutually orthogonal polarization components in incident visible light. The first phase difference plate 13 is positioned opposite the display surface 111 of the image display unit 11. In this embodiment, the first phase difference plate 13 is a quarter-wave plate that provides a 90° phase difference, emits linearly polarized incident light as circularly polarized light, and emits circularly polarized light as linearly polarized light.

[0019] The semi-transparent mirror 14 is an optical element that reflects a portion of the incident visible light and transmits the remainder. The transmittance of the semi-transparent mirror 14 may be about 50%, and the reflectance of the semi-transparent mirror 14 may be about 50%, but is not limited to these values. The semi-transparent mirror 14 is positioned opposite the first phase difference plate 13 and is spaced at a predetermined distance (11th interval) from the first phase difference plate 13. The semi-transparent mirror 14 may have a function to collect or focus light. Specifically, the semi-transparent mirror 14 may have a function to collect or focus light that has been incident on and reflected by the semi-transparent mirror 14. The semi-transparent mirror 14 may have a concave surface facing the second phase difference plate 15. That is, the semi-transparent mirror 14 may have a convex surface facing the first phase difference plate 13.

[0020] The second phase difference plate 15, like the first phase difference plate 13, is an optical element that emits light with a phase difference between mutually orthogonal polarization components in incident visible light. The second phase difference plate 15 is positioned opposite the semi-transparent mirror 14 and is spaced at a predetermined distance (12th interval) from the semi-transparent mirror 14. In this embodiment, the second phase difference plate 15, like the first phase difference plate 13, is a quarter-wave plate and provides a phase difference of 90°.

[0021] The reflective polarizer 16 is an optical element that reflects a predetermined polarization of incident visible light and transmits a predetermined other polarization. On the surface of the reflective polarizer 16 facing the second phase difference plate 15, it reflects a first linearly polarized light (S-polarized light in the above example) and transmits a second linearly polarized light (P-polarized light in the above example) that is orthogonal to the first linearly polarized light. The reflective polarizer 16 faces the second phase difference plate 15 and is arranged at a predetermined distance (13th interval) from the second phase difference plate 15. The reflective polarizer 16 comprises, for example, a plate-shaped substrate that transmits visible light and a plurality of parallel metal fine wires formed on the substrate. The plurality of metal fine wires are referred to as a so-called wire grid. The substrate is made of, for example, glass, acrylic resin, and polycarbonate resin. The plurality of metal fine wires are made of, for example, aluminum (Al), chromium (Cr), and titanium oxide (TiO). ２ It is made of a metal (including alloys) such as ). Such a reflective polarizing plate 16 reflects polarization components parallel to the wire grid (the extension direction of the thin metal wires) and transmits polarization components perpendicular to the wire grid.

[0022] The image display unit 11 is positioned between the focal point of the optical system 12 and the position of the first phase difference plate 13 when the display unit 10 forms a virtual image. The virtual image is formed and visible to the viewer. When the display unit 10 forms a real image, the image display unit 11 is positioned further away from the first phase difference plate 13 than the focal point of the optical system 12. The real image may be projected onto a predetermined screen and visible to the viewer, or it may be formed as a floating image in the air and visible to the viewer.

[0023] In a display unit 10 with this configuration, as shown in the lower part of Figure 2, the light of the image displayed on the image display unit 11 (image light) is incident on the first phase difference plate 13 of the quarter-wave plate as first linearly polarized light (S-polarized light in the above example), and is emitted from the first phase difference plate 13 as circularly polarized light (for example, circularly polarized light that is clockwise in the direction of propagation). The circularly polarized image light emitted from the first phase difference plate 13 is incident on the semi-transparent mirror 14, where a portion is reflected and the remainder is transmitted. The circularly polarized image light that has passed through the semi-transparent mirror 14 is incident on the second phase difference plate 15 of the quarter-wave plate, and is emitted from the second phase difference plate 15 as first linearly polarized light (S-polarized light) from circularly polarized light. The first linearly polarized (S-polarized) image light emitted from the second phase difference plate 15 is incident on the reflective polarizer 16, reflected by the reflective polarizer 16, and its propagation direction is folded back. The first linearly polarized (S-polarized) image light reflected by the reflective polarizer 16 is incident on the second phase difference plate 15 of the quarter-wave plate, where it is converted from the first linearly polarized (S-polarized) light to circularly polarized light (for example, circularly polarized light rotated clockwise in the direction of propagation) and emitted. The circularly polarized image light emitted from the second phase difference plate 15 is incident on the semi-transparent mirror 14, where a portion is reflected and the propagation direction is folded back again, and the remainder is transmitted. The circularly polarized (for example, circularly polarized light rotated counterclockwise in the direction of propagation) image light reflected by the semi-transparent mirror 14 is incident on the second phase difference plate 15 of the quarter-wave plate, where it is converted from circularly polarized light to second linearly polarized (P-polarized) light and emitted. The second linearly polarized (P-polarized) image light emitted from the second phase difference plate 15 is incident on the reflective polarizer 16 and transmitted through the reflective polarizer 16. In this display unit 10, the image light emitted from the optical system 12 is 25% of the light intensity of the image light displayed on the image display unit 11.

[0024] Furthermore, the first and second display units 10a and 10b may be replaced by the display unit 20 of the second embodiment or the display unit 30 of the third embodiment, respectively, instead of the display unit 10 of the first embodiment. In addition, display units equipped with optical systems of other configurations may be used.

[0025] As shown in Figure 3, for example, the display unit 20 includes an image display unit 21 and an optical system 22. The image display unit 21 in the display unit 20 of the second embodiment is the same as the image display unit 11 in the display unit 10 of the first embodiment, so its description is omitted.

[0026] The optical system 22 forms the image of the image displayed on the image display unit 21. In the example shown in Figure 3, the optical system 22 includes a first reflective polarizer 23, a first phase difference plate 24, a semi-transparent mirror 25, a second phase difference plate 26, and a second reflective polarizer 27. These optical elements 23 to 27 are arranged sequentially in this order with respect to the display surface 211 of the image display unit 21, moving away from the display surface 211.

[0027] The first reflective polarizer 23 is an optical element that reflects a predetermined polarization of incident visible light and transmits a predetermined other polarization, similar to the reflective polarizer 16 in the display unit 10 of the first embodiment. The first reflective polarizer 23 is arranged to face the display surface 211 of the image display unit 21. The first reflective polarizer 23 may have a function to collect or focus light. Specifically, the first reflective polarizer 23 may have a function to collect or focus light that is incident on and reflected by the first reflective polarizer 23. The first reflective polarizer 23 may have a concave surface (first concave surface) facing the first phase difference plate 24, and the first concave surface may transmit a first linearly polarized light (S-polarized light in the above example) and reflect a second linearly polarized light (P-polarized light) that is orthogonal to the first linearly polarized light. The first reflective polarizing plate 23 comprises, for example, a plate-shaped substrate that transmits visible light and has the concave surface formed thereon, and a plurality of fine metal wires formed on the substrate and parallel to each other on the concave surface.

[0028] The first phase difference plate 24, like the first phase difference plate 13 in the display unit 10 of the first embodiment, is an optical element that emits light with a phase difference between mutually orthogonal polarization components in incident visible light. The first phase difference plate 24 is positioned opposite the first reflective polarizer 23 and is spaced at a predetermined distance (21st interval) from the first reflective polarizer 23. In this embodiment, the first phase difference plate 24 is a quarter-wave plate and provides a phase difference of 90°.

[0029] The semi-transparent mirror 25 is an optical element that reflects a portion of the incident visible light and transmits the remainder, similar to the semi-transparent mirror 14 in the display unit 10 of the first embodiment. The transmittance of the semi-transparent mirror 25 may be about 50%, and the reflectance of the semi-transparent mirror 25 may be about 50%, but is not limited to these values. The semi-transparent mirror 25 is positioned opposite the first phase difference plate 24 and is located at a predetermined distance (22nd distance) from the first phase difference plate 24.

[0030] The second phase difference plate 26, like the first phase difference plate 13 in the display unit 10 of the first embodiment, is an optical element that emits light with a phase difference between mutually orthogonal polarization components in incident visible light. The second phase difference plate 26 is positioned opposite the semi-transparent mirror 25 and is located at a predetermined distance (23rd interval) from the semi-transparent mirror 25. In this embodiment, the second phase difference plate 26, like the first phase difference plate 24, is a quarter-wave plate and provides a phase difference of 90°.

[0031] The second reflective polarizer 27 is an optical element that reflects a predetermined polarization of incident visible light and transmits a predetermined other polarization, similar to the reflective polarizer 16 in the display unit 10 of the first embodiment. The second reflective polarizer 27 is positioned opposite the second phase difference plate 26 and is spaced at a predetermined interval (24th interval) from the second phase difference plate 26. On the surface facing the second phase difference plate 26, the second reflective polarizer 27 reflects a first linearly polarized light (S-polarized light in the above example) and transmits a second linearly polarized light (P-polarized light) that is orthogonal to the first linearly polarized light. The second reflective polarizer 27 comprises, for example, a plate-shaped substrate that transmits visible light and a plurality of parallel metal wires formed on the substrate. An absorptive polarizer may be used instead of the second reflective polarizer 27. An absorptive polarizer is an optical element that absorbs a predetermined polarization of incident visible light and transmits a predetermined other polarization. Absorption polarizers may be, for example, iodine-based polarizers in which an iodine compound is adsorbed and oriented on a polyvinyl alcohol (PVA) film, or dye-based polarizers in which a dichroic organic dye is adsorbed and oriented on a PVA film.

[0032] The image display unit 21 is positioned between the focal point of the optical system 22 and the position of the first reflective polarizer 23 when the display unit 20 forms a virtual image. The virtual image is formed and visible to the viewer's eye. When the display unit 20 forms a real image, the image display unit 21 is positioned further away from the first reflective polarizer 23 than from the focal point of the optical system 22. The real image may be projected onto a predetermined screen and visible to the viewer, or it may be formed as a floating image in the air and visible to the viewer.

[0033] In a display unit 20 with this configuration, as shown in the lower part of Figure 3, the light of the image displayed on the image display unit 21 (image light) is incident on the first reflective polarizer 23 as first linearly polarized light (S-polarized light in the above example) and passes through the first reflective polarizer 23. The first linearly polarized (S-polarized) image light emitted from the first reflective polarizer 23 is incident on the first phase difference plate 24 of the quarter-wave plate, where it is converted from first linearly polarized light to circularly polarized light (for example, circularly polarized light that is clockwise in the direction of propagation) and emitted. The circularly polarized image light emitted from the first phase difference plate 24 is incident on the semi-transparent mirror 25, where a portion is reflected and the propagation direction is folded back, and the remainder is transmitted. The circularly polarized image light that has passed through the semi-transparent mirror 24 is incident on the second phase difference plate 26 of the quarter-wave plate, where it is converted from circularly polarized light to first linearly polarized light (S-polarized light) and emitted. The first linearly polarized (S-polarized) image light emitted from the second phase difference plate 26 is incident on the second reflective polarizer plate 27 and reflected by the second reflective polarizer plate 27. On the other hand, the circularly polarized (for example, counterclockwise circularly polarized in the direction of propagation) image light reflected by the semi-transparent mirror 25 is incident on the first phase difference plate 24 of the quarter-wave plate, and is emitted from the first phase difference plate 24 as second linearly polarized (P-polarized) light. The second linearly polarized (P-polarized) image light emitted from this first phase difference plate 24 is incident on the first reflective polarizer plate 23, is reflected by the first reflective polarizer plate 23, and the propagation direction is folded back again. The second linearly polarized (P-polarized) image light reflected by the first reflective polarizer 24 is incident on the first phase difference plate 24 of the quarter-wave plate, where it is converted from second linearly polarized (P-polarized) to circularly polarized (for example, counterclockwise circularly polarized) light in the direction of propagation and emitted. The circularly polarized image light emitted from the first phase difference plate 24 is incident on the semi-transparent mirror 25, where a portion is reflected and the remainder is transmitted. The circularly polarized image light that has passed through the semi-transparent mirror 25 is incident on the second phase difference plate 26 of the quarter-wave plate, where it is converted from circularly polarized to second linearly polarized (P-polarized) light and emitted. The second linearly polarized (P-polarized) image light emitted from the second phase difference plate 26 is incident on the second reflective polarizer 27 and transmitted through the second reflective polarizer 27. In this display unit 20, the image light emitted from the optical system 22 is 25% of the light intensity of the image light displayed on the image display unit 21.

[0034] The display unit 30 comprises, for example, an image display unit 31 and an optical system 32, as shown in Figure 4. The image display unit 31 in the display unit 30 of the third embodiment is the same as the image display unit 11 in the display unit 10 of the first embodiment, so its description is omitted.

[0035] The optical system 32 forms the image of the image displayed on the image display unit 31. In the example shown in Figure 4, the optical system 22 includes a first reflective polarizer 33, a first phase difference plate 34, a semi-transparent mirror 35, a second phase difference plate 36, and a second reflective polarizer 37. These optical elements 33 to 37 are arranged sequentially in this order with respect to the display surface 311 of the image display unit 31, in a direction away from the display surface 311. The first reflective polarizer 33, the first phase difference plate 34, the semi-transparent mirror 35, and the second phase difference plate 36 are the same as the first reflective polarizer 23, the first phase difference plate 24, the semi-transparent mirror 25, and the second phase difference plate 26 in the display unit 20 of the second embodiment, so their explanation is omitted.

[0036] The second reflective polarizer 37 is an optical element that reflects a predetermined polarization of incident visible light and transmits a predetermined other polarization, similar to the reflective polarizer 16 in the display unit 10 of the first embodiment. The second reflective polarizer 37 is arranged to face the second phase difference plate 36. The second reflective polarizer 37 has a concave surface (second concave surface) facing the second phase difference plate 36, and at the second concave surface, it reflects the first linearly polarized light (S-polarized light in the above example) and transmits the second linearly polarized light (P-polarized light) which is orthogonal to the first linearly polarized light. The second reflective polarizer 37 comprises, for example, a plate-shaped substrate that transmits visible light and forms the second concave surface, and a plurality of fine metal wires formed on the substrate and parallel to each other at the second concave surface.

[0037] The image display unit 31 is positioned between the focal point of the optical system 32 and the position of the first reflective polarizer 33 when the display unit 30 forms a virtual image. The virtual image is formed and visible to the viewer. When the display unit 30 forms a real image, the image display unit 31 is positioned further away from the first reflective polarizer 33 than from the focal point of the optical system 32. The real image may be projected onto a predetermined screen and visible to the viewer, or it may be formed as a floating image in the air and visible to the viewer.

[0038] In a display unit 30 with this configuration, as shown in the lower part of Figure 4, the light of the image displayed on the image display unit 31 (image light) is emitted from the second reflective polarizing plate 37 through two optical paths, the first and second, because the second reflective polarizing plate 37 has a second concave surface facing the second phase difference plate 36.

[0039] In the first optical path, as shown in the upper part of Figure 4B, the first linearly polarized light (S-polarized light in the above example) is incident on the first reflective polarizer 33 and passes through the first reflective polarizer 33. The first linearly polarized (S-polarized) image light emitted from the first reflective polarizer 33 is incident on the first phase difference plate 34 of the quarter-wave plate, where it is converted from first linearly polarized light to circularly polarized light (for example, circularly polarized light that rotates clockwise in the direction of propagation) and emitted. The circularly polarized image light emitted from the first phase difference plate 34 is incident on the semi-transparent mirror 35, where a portion is reflected and the propagation direction is folded back, and the remainder is transmitted. The circularly polarized image light that has passed through the semi-transparent mirror 35 is emitted from the second reflective polarizer 37 in the second optical path, as will be described later. On the other hand, the circularly polarized image light (for example, circularly polarized light rotating counterclockwise in the direction of propagation) reflected by the semi-transparent mirror 35 is incident on the first phase difference plate 34 of the quarter-wave plate, where it is converted from circularly polarized light to second linearly polarized light (P-polarized light) and emitted. This second linearly polarized (P-polarized) image light emitted from the first phase difference plate 34 is incident on the first reflective polarizer 33, where it is reflected and its propagation direction is folded back again. This second linearly polarized (P-polarized) image light reflected from the first reflective polarizer 33 is incident on the first phase difference plate 34 of the quarter-wave plate, where it is converted from second linearly polarized light (P-polarized light) to circularly polarized light (for example, circularly polarized light rotating counterclockwise in the direction of propagation) and emitted. This circularly polarized image light emitted from the first phase difference plate 34 is incident on the semi-transparent mirror 35, where a portion is reflected and the remainder is transmitted. The circularly polarized image light that passes through the semi-transparent mirror 35 is incident on the second phase difference plate 36 of the quarter-wave plate, where it is converted from circularly polarized light to second linearly polarized light (P-polarized light) and emitted. This second linearly polarized (P-polarized) image light emitted from the second phase difference plate 36 is incident on the second reflective polarizer 37 and passes through the second reflective polarizer 37.

[0040] In the second optical path, as shown in the lower part of the lower section of Figure 4, the circularly polarized image light transmitted through the semi-transparent mirror 35 is incident on the second phase difference plate 36 of the quarter-wave plate, where it is converted from circularly polarized light to first linearly polarized light (S-polarized light) and emitted. This first linearly polarized (S-polarized) image light emitted from the second phase difference plate 36 is incident on the second reflective polarizer 37, where it is reflected and its propagation direction is reversed. This first linearly polarized (S-polarized) image light reflected by the second reflective polarizer 37 is incident on the second phase difference plate 36 of the quarter-wave plate, where it is converted from first linearly polarized light (S-polarized light) to circularly polarized light (for example, circularly polarized light that is clockwise in the direction of propagation) and emitted. The circularly polarized image light emitted from the second phase difference plate 36 is incident on the semi-transparent mirror 35, where a portion is reflected and the propagation direction is folded back again, and the remainder is transmitted. The circularly polarized image light (for example, circularly polarized in a counterclockwise direction in the direction of propagation) reflected by the semi-transparent mirror 35 is incident on the second phase difference plate 36 of the quarter-wave plate, where it is converted from circularly polarized light to second linearly polarized light (P-polarized light) and emitted. The second linearly polarized (P-polarized) image light emitted from the second phase difference plate 36 is incident on the second reflective polarizer 37 and is transmitted through the second reflective polarizer 37.

[0041] In this display unit 30, with respect to the amount of light of the image light displayed on the image display unit 31, the image light emitted from the optical system 32 in the first optical path is 25% of the amount of light, and the image light emitted from the optical system 32 in the second optical path is also 25% of the amount of light. Therefore, with respect to the amount of light of the image light displayed on the image display unit 31, the image light emitted from the optical system 32 is 50% (= 25 + 25).

[0042] In these first to third embodiments, the display units 10, 20, and 30 fold back the optical path, allowing the optical systems 12, 22, and 32 to be thinner when forming an image of the same size compared to when the optical path is not folded back.

[0043] In the above description, the display device 1000a is provided with multiple display units in the same manner, but it may also be provided with multiple display units in different manners. For example, the display device 1000 may be provided with a first display unit 10a in the first manner and a display unit 20b in the second manner. Alternatively, for example, the display device 1000 may be provided with a first display unit 20a in the second manner and a display unit 30b in the third manner.

[0044] In one example, the display device 1000a with such a configuration may be mounted on a mobile body, as shown in Figure 5. The mobile body may be a vehicle VC, an aircraft, or a ship. The vehicle VC is not limited to a passenger car, but may be a large vehicle such as a truck, bus, or trolleybus, or a motorcycle. The display device 1000a may be mounted on the vehicle VC, for example, as a cluster 41 on the dashboard (instrument panel) of the vehicle VC. Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as a HUD (Head Up Display) 42. Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as a CID (Center Information Display) 43. Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as the PID (Passenger Information Display) 44 of the vehicle VC. Alternatively, for example, the display device 1000a may be mounted on the vehicle as the rearview mirror 45 of the vehicle VC. As an example of this disclosure, a display system may be configured comprising the display device 1000a and a camera that captures the scenery around a moving object. Here, the scenery around the moving object may be at least one of the front, rear, side, above, and below the moving object. The display device 1000a may be able to communicate with the camera CAB and may display images captured by the camera CAB on the image display unit. The vehicle VC is provided with a camera CAB that captures the area behind the vehicle VC, and the display device 1000a as the rearview mirror 45 displays the images captured by the camera CAB. Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as digital side mirrors 46R and 46L of the vehicle VC. The digital side mirror 46R is positioned on the right A-pillar of the vehicle VC, and the digital side mirror 46L is positioned on the left A-pillar of the vehicle VC. The vehicle VC is equipped with a camera CAR that captures images of the right rear of the vehicle VC, and the display device 1000a as the digital side mirror 46R displays the images captured by the camera CAR. The vehicle VC is also equipped with a camera CAL that captures images of the left rear of the vehicle VC, and the display device 1000a as the digital side mirror 46L displays the images captured by the camera CAL.Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as the RSE (Rear Seat Entertainment) 47 of the vehicle VC. The upper part of FIG. 5 shows the RSE 47 provided at the rear part around the headrest in the driver's seat FS, but the display device 1000a as the RSE 47 may be provided at the rear part around the headrest in the passenger seat. Alternatively, for example, the display device 1000a may be mounted on the vehicle VC as a door mirror (not shown) of the vehicle VC. The display device 1000a is used as two of these cluster 41, HUD 42, CID 43, PID 44, rearview mirror 45, digital side mirror 46R, and the possible side mirror 46L.

[0045] For example, when the display device 1000a is used as the front 41 and HUD 42, the second display unit 10b (20b, 30b) is used as the front 41, and the first display unit 10a (20a, 30a) is used as the HUD 42. In this case, the windshield (windshield) WS of the vehicle VC is used as a so-called HUD combiner. Alternatively, for example, the windshield WS is provided with a semi-transparent mirror 51 that reflects image light near the dashboard, and the semi-transparent mirror 51 functions as a HUD combiner. When the first display unit 10a is used as the HUD 42, the combiner is included in the optical system 12a. The display device 1000a is mounted on the vehicle VC such that the normals of the image planes of the first and second display units 10a and 10b intersect at one point. For example, as shown in the upper part of Figure 1, the display device 1000 is mounted on a vehicle VC such that the first normal vector NLa on the image plane IMa of the first display unit 10a and the second normal vector NLb on the image plane IMb of the second display unit 10b intersect at a single point at the eye position PS2 of the viewer CL who views the image formed by the first and second display units 10a and 10b, respectively. In this case, as shown in the upper part of Figure 1, the second display unit 10b is arranged such that the optical path of the second image display unit 11b intersects with the optical path of the first image display unit 10a within the first optical system 12a. That is, the first and second display units 10a and 10b are arranged such that the intersection point PS1 is within the first optical system 12a. Furthermore, the first and second display units 10a and 10b may be arranged such that their respective optical paths LPa and LPb intersect within the first optical system 12a and the second optical system 12b. As shown in the upper part of Figure 1, the first and second display units 10a and 10b are arranged such that the first distance from the viewer CR who views the respective image to the first image IMa of the first display unit 10a is different from the second distance from the viewer CR to the second image IMb of the second display unit 10b. This improves the sense of depth. Alternatively, the first and second display units 10a and 10b may be arranged such that the first distance from the viewer CR who views the respective first and second image to the first image of the first display unit 10a is equal to the second distance from the viewer CR to the second image of the second display unit 10b.

[0046] Alternatively, for example, when the display device 1000a is used as the RSE at the rear of the driver's seat and the RSE at the rear of the front passenger's seat, the display device 1000a further includes a reflecting mirror 52 that reflects image light, with the first display unit 10a disposed on the inner surface of the fifth member MB5. As shown in FIG. 6, a viewing window is formed in the sixth member MB6, and a window member is fitted and fixed in the viewing window. The reflecting mirror 52 is disposed such that the reflecting surface intersects the normal line of the display surface 111 in the image display unit 11 of the first display unit 10a at 45 degrees. The image light of the image display unit 11 is bent by 90 degrees by the reflecting mirror in its propagation direction and becomes parallel to the image light of the image display unit 11 in the second display unit 10b. The display device 1000a is disposed at the rear of the front passenger's seat and provides images to the first and second passengers CR1 and CR2 who are seated side by side in the rear seat RS. The imaging image of the image by the first display unit 10a is visually recognized by the first passenger CR1, and the imaging image of the image by the second display unit 10b is visually recognized by the second passenger CR2. In this case, as shown in FIG. 6, the first and second display units 10a and 10b are respectively arranged such that the first distance from the first viewer CR1 who views the first imaging image IMa of the first display unit 10a to the first imaging image IMa of the first display unit 10a is equal to the second distance from the second viewer CR2 who views the second imaging image IMb of the second display unit 10b to the second imaging image IMb of the second display unit 10b.

[0047] For example, the first and second display units 10a and 10b may be arranged such that the third distance from the image display unit 11a to the first imaging image IMa of the first display unit 10a is different from the fourth distance from the image display unit 11b to the second imaging image IMb of the second display unit 10b. Also, for example, the first and second display units 10a and 10b may be arranged such that the third distance from the image display unit 11a to the first imaging image IMa of the first display unit 10a is equal to the fourth distance from the image display unit 11b to the second imaging image IMb of the second display unit 10b.

[0048] As described above, in the display device 1000a of the first embodiment, the multiple pairs of first and second display units 10a and 10b are simply arranged so that their respective optical paths PLa and PLb intersect, thus improving the design flexibility of a display device 1000a equipped with multiple display units 10 (10a, 10b). The above-mentioned display device 1000a uses a display unit of any of the first, second, and third embodiments of the display units 10, 20, and 30, so it can be miniaturized.

[0049] Next, another embodiment will be described.

[0050] (Second Embodiment) The display device 1000b in the second embodiment includes first and second display units 10a (20a, 30a) and 10b (20b, 30b) arranged so that their respective optical paths intersect, similar to the display device 1000a in the first embodiment. In the display device 1000b in the second embodiment, at least one of the first and second display units 10a and 10b changes at least one of the distance DS from the viewer CR who views the image to the image and the magnification m.

[0051] If the focal length of the optical system (lens) is f, the distance of the object from the optical system is a, and the distance of the image formed by the optical system (image) from the optical system is b, then the following equation 1, which is the so-called lens formula, holds true. The magnification m is given by the following equation 2, by definition. Here, in the display units 10, 20, and 30 of the first to third embodiments, the optical system (lens) corresponds to optical systems 12 (12a, 12b), 22 (22a, 22b), and 32 (32a, 32b), and the object corresponds to image display units 11, 21, and 31. Equation 1: 1 / f = 1 / a + 1 / b Equation 2: m = |b / a|

[0052] Therefore, when designing optical systems 12, 22, and 32, the focal length f of optical systems 12, 22, and 32 becomes a fixed value. For this reason, if b is a fixed value, the magnification m can be changed by changing distance a. The distance DS from the viewer CR to the image may be changed directly, but if the magnification m is a fixed value, the distance b can be changed by changing distance a, and as a result, the distance DS from the viewer CR to the image can be changed. For this reason, in the second embodiment, distance a is changed.

[0053] Figure 7 is a block diagram showing the configuration of the display device in the second embodiment. The display device 1000b in the second embodiment includes, for example, a plurality of two first and second display units 10a, 10b, a first modification unit 61, a control processing unit 62, a storage unit 63, a detection unit 64, and a search unit 65, as shown in Figure 7.

[0054] In the second embodiment, the display device 1000b may be equipped with any of the display units 10, 20, or 30 of the first to third embodiments as the display unit 10 (10a, 10b), or it may be equipped with a display unit with a different configuration. For the sake of simplicity, the display unit 10 of the first embodiment is used here, and the distance a of the second display unit 10b is changed, as described below. For this reason, only the second display unit 10b is shown in Figure 7, and the illustration of the first display unit 10a is omitted. Note that the distance a of the first display unit 10a may be changed, or both the distance a of the first display unit 10a and the distance a of the second display unit 10b may be changed.

[0055] The first modification unit 61 is a device that modifies at least one of the distance DS from the viewer CR who views the image IMb to the image IMb, and the magnification m, in at least one of the plurality of two first and second display units 10a and 10b, in this case the second display unit 10b. Here, as described above, if distance a is changed and distance b is fixed, the magnification m is changed. On the other hand, if distance a is changed and magnification m is fixed, distance b is changed, and the distance DS from the viewer CR to the image IMb is changed.

[0056] The first modification unit 61 more specifically comprises a first implementation unit 611 and a first input unit 612.

[0057] The first input unit 612 is connected to the control processing unit 62 and is a device that receives input of a first change amount, which is at least one of distance DS and magnification m. In this embodiment, the change amount of distance a is input as the first change amount. The first input unit 612 outputs the received first change amount to the control processing unit 62. More specifically, the first input unit 612 includes, for example, a first sub-input unit that receives input of an increase in the first change amount and a second sub-input unit that receives input of a decrease in the first change amount. The first sub-input unit includes, for example, a slide switch, and the increase in the first change amount is input by the slide amount. Alternatively, for example, the first sub-input unit includes a rotary switch, and the increase in the first change amount is input by the rotation amount. Similarly, the second sub-input unit includes, for example, a slide switch, and the decrease in the first change amount is input by the slide amount. Alternatively, for example, the second sub-input unit includes a rotary switch, and the decrease in the first change amount is input by the rotation amount. The increase may be an increase relative to the current distance a, or an increase relative to a preset default distance a. The decrease may be a decrease relative to the current distance a, or a decrease relative to the default distance a.

[0058] Alternatively, for example, the first input unit 612 has an operating surface and includes an input position detection unit (e.g., a touch sensor), such as a resistive type or a capacitive type, which detects the input position on the operating surface. When such a first input unit 612 is combined with the image formed by the second display unit 10b, a so-called touch panel (touch panel display) is configured. In this case, each position on the operating surface corresponds to each position on the display surface 111 of the image display unit 11 (each position in the image). The image formed by the second display unit 10b includes a first sub-input button for inputting an increase in the first change amount and a second sub-input button for inputting a decrease in the first change amount. By inputting the position on the operating surface corresponding to the display position of the first sub-input button, the increase in the first change amount is input. By inputting the position on the operating surface corresponding to the display position of the second sub-input button, the decrease in the first change amount is input. When the touch panel is configured, the input position detection unit, which serves as the first input unit 612, may be located in the second viewing window WDb or on the second window member WMb. In this case, the input position detection unit is formed to transmit wavelengths of visible light.

[0059] The first implementation unit 611 is a device that changes at least one of the distance and the magnification ratio according to the first change amount received by the first input unit 612. In this embodiment, as described above, the first implementation unit 611 changes the distance a. More specifically, the first implementation unit 611 comprises a first change mechanism 6111, a first change drive unit 6112, and a first drive control unit 6113 (624).

[0060] The first drive control unit 6113 (624) is functionally configured in the control processing unit 62 and controls the first change drive unit 6112 so that it becomes the first change amount input at the first input unit 612. The first change drive unit 6112 is a device that drives the first change mechanism 6111 so that it becomes the first change amount input at the first input unit 612, in accordance with the control of the first drive control unit 6113 (624). The first change drive unit 6112 includes a motor, such as a stepping motor and a servo motor. The first change mechanism 6111 is a mechanism that is driven by the first change drive unit 6112 and changes the distance a so that it becomes the first change amount input at the first input unit 612. The first change mechanism 6111 includes, for example, an X-stage that moves in one direction. The optical system 12 is fixedly attached to the housing HSA. The X-stage is fixedly attached to the housing HSA so that the one direction is along the direction of distance a. An image display unit 11 is fixedly mounted on the stage such that the display surface 111 is perpendicular to the aforementioned direction. The distance a is changed by moving the stage. Alternatively, for example, the first changing mechanism 6111 includes a rack and pinion. The optical system 12 is fixedly mounted on the housing HSA. The rack of the rack and pinion is movably arranged within the housing HSA such that its extension direction is along the direction of distance a. An image display unit 11 is fixedly mounted on the rack such that the display surface 111 is perpendicular to the extension direction. The pinion of the rack and pinion is attached to a first changing drive unit 6112 which is fixedly mounted on the housing HSA. For example, the pinion is mounted on the output shaft of a stepping motor. The distance a is changed by rotating the pinion.

[0061] The detection unit 64 is connected to the control processing unit 62 and is a device that detects the eye position of the viewer CR according to the control of the control processing unit 62. The detection unit 64 outputs the detected eye position of the viewer CR to the control processing unit 62. The detection unit 64 includes, for example, an eye tracker that tracks the eye position. The eye position may be defined as, for example, the position of the right eye, or for example, the position of the left eye, or for example, the midpoint between both eyes (the average position of the right eye position and the left eye position), and may be defined as appropriate in advance.

[0062] The investigation unit 65 is connected to the control processing unit 62 and is a device that investigates at least one of the position and orientation of the seat according to the control of the control processing unit 62. The investigation unit 65 outputs at least one of the position and orientation it has investigated to the control processing unit 62. The investigation unit 65 includes, for example, a detection sensor that detects at least one of the position and orientation. Alternatively, for example, the investigation unit 65 includes a second input unit that receives input for the adjustment amount of at least one of the position and orientation. The position of the seat is represented by the position of the seat surface along the normal NLb of the image plane in the image IMb formed by the second display unit 10b. More specifically, the display device 1000b is mounted on, for example, a vehicle, the seat is a seat in the vehicle, and the position of the seat is represented by the position of the seat surface (front-to-back position) in the vehicle length direction. In this case, the line segment along the normal NLb will be projected onto the line segment along the vehicle length direction. In the display device described above, the seat posture is represented by the height and inclination angle (first inclination angle) of the seat surface and the inclination angle (second inclination angle) of the seat back. The second input unit includes a seat position input unit for inputting a first adjustment amount for the seat position, a seat surface height input unit for inputting a second adjustment amount for the height of the seat surface, a seat surface inclination angle input unit for inputting a third adjustment amount for the first inclination angle of the seat surface, and an SB inclination angle input unit for inputting a fourth adjustment amount for the second inclination angle of the seat back. As the seat position is moved forward, the position of the viewer's eyes moves forward. As the seat surface is raised, the height of the viewer's eyes increases. As the rear of the seat surface is lowered relative to the front, the height of the viewer's eyes decreases. As the seat back is made vertical, the viewer's eyes move forward and become higher.

[0063] The storage unit 63 is connected to the control processing unit 62 and is a circuit that stores various predetermined programs and various predetermined data in accordance with the control of the control processing unit 62.

[0064] The various predetermined programs mentioned above include, for example, a control processing program, which includes, for example, a control program, a first processing program, a second processing program, and a first drive control program. The control program is a program that controls each part 10 (10a, 10b), 61, 63-65 of the display device 1000b according to the function of each part. The first processing program is a program that determines a first change amount based on the eye position detected by the detection unit 64, and determines the first change amount based on at least one of the position and orientation investigated by the investigation unit 65. The second processing program is a program that processes each image displayed on each of the plurality of display units 10 (20, 30). The first drive control program is a program that controls the first change drive unit 6112 so that it becomes the first change amount input by the first input unit 612.

[0065] The various predetermined data mentioned above include, for example, data necessary for executing each of these programs, such as the first change amount received by the first input unit 612, the first change amount obtained by the first processing program, conversion information (first conversion information) that converts the eye position detected by the detection unit 64 into the first change amount, and conversion information (second conversion information) that converts at least one of the position and posture investigated by the investigation unit 65 into the first change amount. The first and second conversion information are each appropriately created in advance from, for example, a plurality of samples and stored in the storage unit 63.

[0066] Such a storage unit 63 may include, for example, a non-volatile memory element such as ROM (Read Only Memory) or a rewritable non-volatile memory element such as EEPROM (Electrically Erasable Programmable Read Only Memory). Furthermore, the storage unit 63 may include RAM (Random Access Memory) or the like, which serves as the working memory of the so-called control processing unit 62 that stores data generated during the execution of the predetermined program. In addition, the storage unit 63 may be configured to include a hard disk drive or solid-state drive (SSD) with a relatively large storage capacity.

[0067] The control processing unit 62 controls each part 10 (10a, 10b), 61, 63-65 of the display device 1000b according to the function of each part, processes each image displayed on the plurality of two first and second display units 10a, 10b, and is a circuit for changing the distance a of at least one of the plurality of two first and second display units 10a, 10b, in this case the second display unit 10b. The control processing unit 62 is configured, for example, with a CPU (Central Processing Unit) and its peripheral circuits. When the control processing program is executed, the control unit 622 is functionally configured with a control unit 621, a second processing unit 622, a first processing unit 623, and a first drive control unit 624 (6113).

[0068] The control unit 621 controls each part 10 (10a, 10b), 61, 63-65 of the display device 1000b according to the function of each part, and is in charge of the overall control of the display device 1000b.

[0069] The first processing unit 623 uses the first conversion information to determine the first change amount based on the eye position detected by the detection unit 64. The first processing unit 623 uses the second conversion information to determine the first change amount based on at least one of the position and orientation investigated by the investigation unit 65.

[0070] As described above, the first drive control unit 624 (6113) controls the first change drive unit 6112 so that it becomes the first change amount input by the first input unit 612. In this embodiment, the first drive control unit 624 (6113) further controls the first change drive unit 6112 so that it becomes the first change amount determined by the first processing unit 623. Then, in this embodiment, as will be described later, the first drive control unit 624 (6113) further controls the first change drive unit 6112 so that it becomes the second change amount notified by the second processing unit 622.

[0071] Therefore, in this embodiment, the first implementation unit 611, which includes a first drive control unit 624 (6113), a first change drive unit 6112, and a first change mechanism 6111, corresponds to an example of a first implementation unit that changes at least one of the distance and the magnification ratio according to a first change amount received by the first input unit, and also corresponds to an example of a first implementation unit that changes at least one of the distance and the magnification ratio according to a first change amount determined by the first processing unit.

[0072] More specifically, when the display device 1000b is mounted on a vehicle and at least one of the distance and the magnification is changed according to the first change amount determined by the first processing unit 623, the first implement unit 611 changes the distance a as shown in the following first to fourth embodiments.

[0073] In the first embodiment, at least one of the distance DS and the magnification m is the distance DS, and at least one of the position and posture is the position. When the seat position is the initial seat position (default seat position) and the distance DS is the initial distance (default distance), the first implement 611 changes the distance DS to be longer than the initial distance in accordance with the first change amount if the first change amount is the amount by which the seat moves closer to the steering wheel (handle) from the initial seat position, and changes the distance DS to be shorter than the initial distance in accordance with the first change amount if the first change amount is the amount by which the seat moves further away from the steering wheel from the initial seat position.

[0074] In the second embodiment, at least one of the distance DS and the magnification m is the distance DS, and at least one of the position and the attitude is the attitude. When the inclination angle is the initial inclination angle (default inclination angle) and the distance DS is the initial distance, the first implement 611 changes the distance DS to be longer than the initial distance according to the first change amount if the first change amount is smaller than the initial inclination angle, and changes the distance DS to be shorter than the initial distance according to the first change amount if the first change amount is larger than the initial inclination angle.

[0075] In the third embodiment, at least one of the distance DS and the magnification m is the magnification m, and at least one of the position and orientation is the position. When the seat position is the initial seat position and the magnification m is the initial magnification (default magnification), the first implement 611 changes the magnification m to be smaller than the initial magnification in accordance with the first change amount if the first change amount is an amount that moves the seat closer to the steering wheel from the initial seat position, and changes the magnification m to be larger than the initial magnification in accordance with the first change amount if the first change amount is an amount that moves the seat further away from the steering wheel from the initial seat position.

[0076] In the fourth embodiment, at least one of the distance DS and the magnification m is the magnification m, and at least one of the position and the attitude is the attitude. When the inclination angle is the initial inclination angle and the magnification m is the initial magnification, the first implement 611 changes the magnification m to be smaller than the initial magnification in accordance with the first change amount if the first change amount is smaller than the initial inclination angle, and changes the magnification m to be larger than the initial magnification in accordance with the first change amount if the first change amount is larger than the initial inclination angle.

[0077] In the first and second embodiments, the first implement 611 changes the distance a so that it becomes the distance DS. In the third and fourth embodiments, the first implement 611 changes the distance a so that it becomes the magnification m.

[0078] The second processing unit 622 processes each image displayed on the plurality of two first and second display units 10a and 10b. More specifically, the second processing unit 622 changes at least one of the distance DS and magnification m of at least one of the plurality of two first and second display units 10a and 10b, in this case the second display unit 10b, by a second change amount based on the content displayed in the image. More specifically, the second processing unit 622 causes the image display unit 11 to display a predetermined image, and if the predetermined image is an image that displays a predetermined content (specific content) that has been set in advance, it notifies the first drive control unit 624 (6113) of the second change amount. Upon receiving this notification, the first drive control unit 624 (6113) controls the first change drive unit 6112 so that it becomes the second change amount notified by the second processing unit 622. Accordingly, the first change drive unit 6112 drives the first change mechanism 6111 to obtain the second change amount, and the first change mechanism 6111 changes the distance a to obtain the second change amount. The specific content is set appropriately in advance, and the second change amount is set appropriately in advance.

[0079] For example, at least one of the distance DS and the magnification m is the distance DS, and the specific content is content that includes a warning. In this case, the second amount of change is the amount by which the distance DS becomes shorter than the initial distance. Therefore, if the content includes a warning, the distance DS is changed to be shorter than the initial distance.

[0080] Alternatively, for example, at least one of the distance DS and the magnification m is the magnification m, and the specific content is content that includes a warning. In this case, the second amount of change is the amount by which the magnification m becomes larger than the initial magnification. Therefore, if the specific content includes a warning, the magnification m is changed to become larger than the initial magnification.

[0081] The content of the warning messages is set in advance as appropriate. For example, if the display device 1000b is installed in a vehicle, the content of the warning messages may include the message "You are exceeding the speed limit" and the message "There is a level crossing ahead."

[0082] Such a second processing unit 622 and first implementation unit 611 correspond to an example of a second modification unit that changes at least one of the distance from the viewer viewing the image to the image and the magnification based on the content displayed in the image.

[0083] In the display device 1000b with this configuration, when the viewer CR inputs a first change amount from the first input unit 612, at least one of the distance DS and magnification m is changed in accordance with the input first change amount for at least one of the two first and second display units 10a and 10b, in this case the second display unit 10b. As a result, the display device 1000b can display an appropriate image to the viewer CR. When the viewer CR is seated, at least one of the distance DS and magnification m is changed in accordance with the first change amount corresponding to the position of the viewer CR's eyes detected by the detection unit 64 for the second display unit 10b. As a result, the display device 1000b can automatically display an appropriate image to the viewer CR and can display an appropriate image for each viewer CR seated in a seat. When at least one of the seat position and posture is changed, at least one of the distance DS and magnification m is changed in the second display unit 10b according to a first change amount corresponding to at least one of the seat position and posture investigated by the investigation unit 65. This allows the display device 1000b to display an appropriate image for each viewer CR seated in the seat. After at least one of the distance DS and magnification m is changed according to the detection result of the detection unit 64, at least one of the distance DS and magnification m may be fine-tuned by the viewer CR using the first input unit 612. After at least one of the distance DS and magnification m is changed according to the results investigated by the investigation unit 65, at least one of the distance DS and magnification m may be fine-tuned by the viewer CR using the first input unit 612.

[0084] Furthermore, if the image formed on the second display unit 10b is specific content, at least one of the distance DS and magnification m is changed according to the second change amount. This allows the display device 1000b to broaden the range of image representation and diversify image representation. If the specific content includes content that prompts attention, the display device 1000b can emphasize the attention.

[0085] As described above, the display device 1000b in the second embodiment can change at least one of the distance DS and magnification m for at least one of the plurality of two first and second display units 10a and 10b. Therefore, the display device 1000b can display an image appropriate to the viewer CR.

[0086] Next, another embodiment will be described.

[0087] (Third Embodiment) The display device 1000d in the third embodiment includes first and second display units 10a (20a, 30a) and 10b (20b, 30b) arranged so that their respective optical paths intersect, similar to the display device 1000a in the first embodiment. In the display device 1000d in the third embodiment, the images displayed on the first and second display units 10a and 10b are controlled.

[0088] Figure 8 is a block diagram showing the configuration of the display device in the third embodiment. The display device 1000d in the third embodiment includes, for example, a plurality of pairs of first and second display units 10a and 10b, a control processing unit 82, and a storage unit 83, as shown in Figure 8.

[0089] In the third embodiment, the display device 1000d may be equipped with any of the display devices 10, 20, or 30 of the first to third embodiments as the plurality of two first and second display units 10a and 10b, or it may be equipped with display units of other configurations. For the sake of simplicity, the first and second display units 10a and 10b of the first embodiment will be used in the following description.

[0090] The memory unit 83 is connected to the control processing unit 82 and is a circuit that stores various predetermined programs and various predetermined data in accordance with the control of the control processing unit 82.

[0091] The various predetermined programs mentioned above include, for example, a control processing program, and the control processing program includes, for example, a control program and an image control program. The control program is a program that controls each part 10 (10a, 10b), 83 of the display device 1000d according to the function of each part. The image control program is a program that controls each image displayed on each of the plurality of two first and second display units 10a, 10b (each image displayed on each of the image display units 11a, 11b).

[0092] The aforementioned various predetermined data include, for example, data necessary for executing each of these programs, such as the images to be displayed on the first and second display units 10a and 10b, respectively.

[0093] The control processing unit 82 is a circuit for controlling each part 10 (10a, 10b), 83 of the display device 1000d according to the function of each part, and for controlling each image displayed on the plurality of two first and second display units 10a, 10b. When the control processing program is executed, the control unit 821 and the image control unit 822 are functionally configured in the control processing unit 82.

[0094] The control unit 821 controls each part 10 (10a, 10b), 83 of the display device 1000d according to the function of each part, and is in charge of the overall control of the display device 1000d.

[0095] The image control unit 822 controls each of the images displayed on the two first and second display units 10a and 10b (each of the images displayed on the image display units 11a and 11b). Since each of the images displayed on the image display units 11a and 11b is controlled, each of the image-formed images formed by the optical systems 12a and 12b is controlled.

[0096] More specifically, the image control unit 822 controls each image in any of the following seventh to tenth embodiments.

[0097] In the seventh embodiment, the image control unit 822 switches between the images of the first and second display units 10a and 10b.

[0098] In the eighth aspect, the image control unit 822 controls the first and second display units 10a and 10b so that the images displayed in the first and second display units 10a and 10b, respectively, form a single image. For example, when the image formed by the first display unit 10a and the image formed by the second display unit 10b are arranged along one direction on one side and the other side, the single image is divided along the one direction into one side image (half image) and the other side half image. The image control unit 822 controls the first display unit 10a to display the one side half image and controls the second display unit 10b to display the other side half image. The one direction may be, for example, the up-and-down direction (vertical direction) or, for example, the left-and-right direction (horizontal direction) when the display device 1000d is installed.

[0099] In the ninth aspect, the image is an image that displays content comprising multiple elements, and the image control unit 822 controls the first and second display units 10a and 10b so that at least one element of the multiple elements moves sequentially from one to the other in each of the first and second display units 10a and 10b. For example, if the content comprises a background image and an image of a moving object as elements, the image control unit 822 controls the first and second display units 10a and 10b so that the image of the moving object moves from the image displayed in the first display unit 10a to the image displayed in the second display unit 10b.

[0100] In the tenth embodiment, the image control unit 822 controls the first and second display units 10a and 10b such that a predetermined image is displayed on one of the first and second display units 10a and 10b, but the predetermined image is not displayed on the other display unit 10.

[0101] In this tenth embodiment, the display device 1000d may further include a fourth input unit 86, as shown by the dashed line in Figure 8. This fourth input unit 86 is connected to the control processing unit 82 and is a device that receives input for specifying which of the first and second display units 10a and 10b will display the predetermined image. The fourth input unit 86 outputs the received specification of the display unit 10 to the control processing unit 82. The fourth input unit 86 includes, for example, a toggle switch. The first display unit 10a is assigned to one contact of the toggle switch, and the second display unit 10b is assigned to the other contact of the toggle switch. The image control unit 822 controls the first and second display units 10a and 10b so as to display the predetermined image on the one designated display unit 10 of the first and second display units 10a and 10b, and so as not to display the predetermined image on the remaining undesignated display unit 10. By providing such a fourth input unit 86, the viewer CR can have an image formed by the desired display unit 10, and the display device 1000d can customize the position where the image is displayed (the display position of the image).

[0102] Furthermore, in this tenth embodiment, the display device 1000d is mounted in the vehicle so that the image-formed images of the first and second display units 10a and 10b can be viewed by the occupant (an example of a viewer CR). The display device 1000d further includes a detection unit 84 for detecting the position of the occupant's eyes, as shown by the dashed line in Figure 8. The detection unit 84 is the same as the detection unit 64 in the display device 1000b of the second embodiment, so its description is omitted. The image control unit 822 determines which of the first and second display units 10a and 10b will display the predetermined image based on the eye position detected by the detection unit 84, and displays the predetermined image in the determined display unit 10. By including such a detection unit 84, the display device 1000d can automatically customize the display position of the image-formed image according to the viewer CR.

[0103] In the display device 1000d with this configuration, each image displayed in the first and second display units 10a and 10b is controlled. In the seventh embodiment, the images in the first and second display units 10a and 10b are switched between each other. This allows the display device 1000d to customize the display position of the image formation according to the viewer's CR. In the eighth embodiment, the first and second display units 10a and 10b are controlled so that each image displayed in the first and second display units 10a and 10b forms a single image. In the ninth embodiment, the first and second display units 10a and 10b are controlled so that at least one element of the plurality of elements moves sequentially from one to the other. According to these eighth and ninth embodiments, the display device 1000d can broaden the range of image representation and diversify image representation. In the tenth embodiment, the first and second display units 10a and 10b are controlled so that a predetermined image is displayed on one of the first and second display units 10a and 10b, and the other display unit 10 is not to display the predetermined image. This allows the display device 1000d to customize the display position of the image according to the viewer CR.

[0104] As described above, the display device 1000d in the third embodiment can control the images displayed on the first and second display units 10a and 10b, respectively.

[0105] Next, another embodiment will be described.

[0106] (Fourth Embodiment) The display device 1000e in the fourth embodiment includes first and second display units 10a (20a, 30a) and 10b (20b, 30b) arranged so that their respective optical paths intersect, similar to the display device 1000a in the first embodiment. The display device 1000e in the fourth embodiment further includes a third display unit 10c (20c, 30c). The optical path of this third display unit is arranged so that it intersects with the optical path of at least one of the first and second image display units.

[0107] Figure 9 is a schematic diagram illustrating the configuration of the display device in the fourth embodiment. The left side of Figure 9 is a top view, and the right side of Figure 9 is a side view. Figure 9 shows the display device 1000e of the fourth embodiment mounted on a left-hand drive vehicle.

[0108] The display device 1000e in the fourth embodiment includes, for example, three first to third display units 10a (20a, 30a), 10b (20b, 30b), and 10c (20c, 30c), as shown in Figure 9, and a housing HSB that houses these first to third display units 10 (20, 30). More specifically, the display device 1000e is the display device 1000a in the first embodiment, further comprising a third display unit 10c and a semi-transparent mirror 53. For this reason, the description of the first and second display units 10a and 10b is omitted.

[0109] The third display unit 10c is positioned such that its optical path LPc is further perpendicular to the intersection point PS1 where the optical paths LPa of the first display unit 10a and LPb of the second display unit 10b intersect. In other words, the first, second, and third display units 10a, 10b, and 10c are positioned such that the optical paths LPa of the first display unit 10a, LPb of the second display unit 10b, and LPc of the third display unit 10c intersect perpendicularly at point PS1. Note that it is sufficient for each optical path LPa, LPb, and LPc to intersect, and the intersection angle is not limited to a right angle.

[0110] More specifically, the housing HSB is similar to the housing HSA in the display device 1000a of the first embodiment. In the housing HSA, the sixth member MB6 does not have a viewing window, but in the housing HSB, the sixth member MB6 has a substantially rectangular through-opening formed as a third viewing window WDc (not shown) for viewing the image (image-formed image) formed by the third display unit 10c. In other words, the housing HSB is the same as the housing HSA except that the sixth member MB6 has a third viewing window WDc, and its explanation is omitted. Note that a third window member WMc (not shown) may be fitted into the third viewing window WDc, similar to the first and second viewing windows WDa and WDb, and the third window member WMc may be omitted. The third display unit 10c has the same configuration as the first and second display units 10a and 10b, and is located on the fifth inner surface WL5 of the fifth member MB5 and housed within the casing.

[0111] In addition, similar to the display device 1000a in the first embodiment, the first to third display units 10a to 10c may be the display unit 20 of the second embodiment, or the display unit 30 of the third embodiment, or different display units 10, 20, and 30 may be used.

[0112] The semi-transparent mirror 53 is an optical element that reflects a portion of the incident visible light and transmits the remainder. The transmittance of the semi-transparent mirror 53 may be approximately 50%. The semi-transparent mirror 53 is positioned so that its semi-transparent surface intersects at a 45-degree angle with the normal to the display surface 111 of the image display unit 11 in the third display unit 10c. The image light from the image display unit 11 has its propagation direction bent at a 90-degree angle by the semi-transparent mirror 53, becoming parallel to the image light from the image display unit 11 in the second display unit 10b.

[0113] In this arrangement of the first to third display units 10a to 10c, the first and second display units 10a and 10b are positioned to be visible to a first viewer CR3, and the third display unit 10c is positioned to be visible to a second viewer CR4 who is different from the first viewer CR3. In one example, the display device 1000e is mounted on a left-hand drive vehicle. In this example, the first viewer CR3 is the driver seated in the driver's seat, and the first display unit 10a (20a, 30a) is used as a HUD. In this case, as described above, the windshield WS of the vehicle VC, or a semi-transparent mirror 51 provided on the windshield WS near the dashboard, functions as a combiner for the HUD. The second display unit 10b is used as the front of the driver, who is the first viewer CR3. The second observer CR4 is an occupant seated in the passenger seat adjacent to the driver's seat, and the third display unit 10c is used as the CID for the occupant as the second observer. The driver and the occupant are seated side by side along a direction parallel to the optical path LPc of the third display unit 10c.

[0114] As described above, in the fourth embodiment, the display device 1000e has a plurality of three first, second, and third display units 10a, 10b, and 10c, which are arranged so that their respective optical paths intersect. This improves the design flexibility of a display device 1000a that has a plurality of display units 10 (10a, 10b, and 10c). In the above display device 1000e, the first, second, and third display units 10a, 10b, and 10c are combined to share space and arranged within a single housing HSB. In the above display device 1000, three images can be formed with a single device. The above display device 1000e can be miniaturized because it uses a display unit of any of the first, second, and third embodiments of the display units 10, 20, and 30.

[0115] In the above-described embodiment, the first and second display units 10a (20a, 30a) and 10b (20b, 30b) may be arranged so that, when viewed by a viewer (CR), the first image formed by the first display unit 10a (20a, 30a) and the second image formed by the second display unit 10b (20b, 30b) are superimposed by at least one portion. This can improve the sense of depth. For example, by arranging the first display unit 10a such that the distance (height) from the first inner surface WL1 is longer (higher) on the side closer to the viewer CR than on the side farther from the viewer CR, the display device 1000a can bring the first image IMa of the first display unit 10a closer to the second image IMb of the second display unit 10b, and can superimpose the first image IMa of the first display unit 10a and the second image IMb of the second display unit 10b (20b, 30b).

[0116] Alternatively, for example, the first image IMa of the first display unit 10a may be formed as a virtual image, and the second image IMb of the second display unit 10b may be formed as a real image, thereby superimposing the first image IMa and the second image IMb.

[0117] The optical systems 12, 22, and 32 are capable of forming a first image IMa that can be viewed outside the housing. In other words, the first image IMa can be viewed without passing through the first viewing window WDa.

[0118] The optical systems 12, 22, and 32 are capable of forming a second image IMb that can be viewed through the second viewing window WDb. In other words, the second image IMb can be viewed by looking through the second viewing window WDb. To put it another way, the second image IMb cannot be viewed without the second viewing window WDb.

[0119] Furthermore, although the display units 10, 20, and 30 of the first to third embodiments were used in the above-described embodiments, the display units of the following fourth to sixth embodiments may also be used.

[0120] Figure 10 is a schematic diagram showing a display device using the display unit of the fourth embodiment as an example. Figure 11 is a schematic diagram showing a display device using the display unit of the fourth embodiment as another example. Figure 12 is a schematic diagram showing a display device using the display unit of the fourth embodiment as yet another example. Figure 13 is a schematic diagram showing a display device using the display unit of the fifth embodiment as an example. Figure 14 is a schematic diagram showing a display device using the display unit of the sixth embodiment as yet another example. Figure 15 is a schematic diagram showing a display device using the display units of the fifth and sixth embodiments as an example. Figure 16 is a schematic diagram showing a display device using the display units of the fifth and sixth embodiments as yet another example.

[0121] The display unit of the fourth embodiment includes, for example, an image display unit 11 (11b, 11a, 11b) for displaying an image, as shown in Figures 10 to 12, and does not include an optical system for forming an image of the image of the image display units 11b, 11a, 11b. In the example shown in Figure 10, the display device 1000f equipped with such a display unit of the fourth embodiment includes the display unit of the fourth embodiment (image display unit 11b) in place of the display unit 10b in the display device 1000a of the first embodiment. Except for this point, the display device 1000f is the same as the display device 1000a, so its description is omitted. In the example shown in Figure 11, the display device 1000g includes the display unit of the fourth embodiment (image display unit 11a) in place of the display unit 10a in the display device 1000a of the first embodiment. Except for this point, the display device 1000g is the same as the display device 1000a, so its description is omitted. Furthermore, when the display unit (image display unit 11a) of the fourth embodiment is used as a HUD 42, the display device 1000g is provided with a combiner as an optical system for the image display unit 11a. In the example shown in Figure 12, the display device 1000h is provided with the display unit (image display unit 11a) of the fourth embodiment in place of the display unit 10a of the display device 1000a of the first embodiment, and with the display unit (image display unit 11b) of the fourth embodiment in place of the display unit 10b of the display device 1000a. The display unit (image display unit 11b) of the fourth embodiment is used as a HUD 42, and the display device 1000h is provided with a combiner as an optical system for the image display unit 11b. Except for these points, the display device 1000h is the same as the display device 1000a, so its description is omitted.

[0122] The display unit 91 (91a, 91b) of the fifth embodiment, as shown in Figure 13, for example, comprises an image display unit 11 (11a, 11b) for displaying an image and a housing HSC (HSC-1, HSC-2) housing the image display unit 11 (11a, 11b), and does not have an optical system for forming an image of the image on the image display unit 11b. More specifically, the display unit 91a of the fifth embodiment comprises an image display unit 11a for displaying an image and a housing HSC-1 housing the image display unit 11a, and is used as a HUD 42, and includes a combiner as an optical system for the image display unit 11a. The housing HSC-1 is similar to the housing HSA in the display device 1000a of the first embodiment. In the housing HSA, a second viewing window WDb is formed in the fourth member MB4, but in the housing HSC-1, the second viewing window WDb is not formed in the fourth member MB4. Except for this point, the housing HSC-1 is the same as the housing HSA, so its description will be omitted. The image display unit 11a is located on the first inner surface (e.g., bottom surface) WL1 inside such a housing and is housed in housing HSC-1. The display unit 91b of the fifth embodiment comprises an image display unit 11b that displays an image and a housing HSC-2 that houses the image display unit 11b, and does not have an optical system for forming an image of the image on the image display unit 11b. Housing HSC-2 is similar to the housing HSA in the display device 1000a of the first embodiment. In housing HSA, the third member MB3 has a first viewing window WDa, but in housing HSC-2, the third member MB3 does not have a first viewing window WDa. Except for this point, housing HSC-2 is the same as housing HSA, so its description will be omitted. The image display unit 11b is located on the second inner surface (for example, the left side when viewing the paper from the front) WL2 within the housing and is housed in the housing HSC-2. In the example shown in Figure 13, the display device 1000i comprises a fifth-mode display unit 91a and a fifth-mode display unit 91b, and these two fifth-mode display units 91a and 91b are arranged so that their respective optical paths intersect at an intersection (crossing point) PS1. In the example shown in Figure 13, the intersection angle is 90°, but the intersection angle is not limited to 90°.

[0123] The display unit 92 (92a, 92b) of the sixth embodiment comprises, for example, a display unit 10 (10a (20a, 30a), 10b (20b, 30b)) and a housing HSC (HSC-1, HSC-2) that houses the display unit 10 (20, 30). That is, in the sixth embodiment, only one display unit 10 (20, 30) is provided in one housing HSC. More specifically, the display unit 92a of the sixth embodiment comprises a display unit 10a (20a, 30a) and a housing HSC-1 that houses this display unit 10a (20a, 30a). This display unit 11a (20a, 30a) is positioned on the first inner surface (e.g., bottom surface) WL1 inside the housing and is housed in housing HSC-1. The sixth embodiment of the display unit 92b comprises a display unit 10b (20b, 30b) and a housing HSC-2 that houses the display unit 10b (20b, 30b). The display unit 10b (20b, 30b) is located on the second inner surface (for example, the left side when viewing the paper from the front) WL2 inside the housing and is housed in the housing HSC-2. In the example shown in Figure 14, the display device 1000j comprises a display unit 92a and a display unit 92b of the sixth embodiment, and these two display units 92a and 92b of the sixth embodiment are arranged so that their respective optical paths intersect at an intersection (crossing point) PS1. In the example shown in Figure 14, the intersection angle is 90°, but the intersection angle is not limited to 90°.

[0124] Furthermore, the display device 1000 may include display units of different embodiments. In the example shown in Figure 15, the display device 1000k includes a sixth-embodied display unit 92a and a fifth-embodied display unit 91b, and these sixth-embodied display unit 92a and fifth-embodied display unit 91b are arranged so that their respective optical paths intersect at the intersection (crossing point) PS1. In the example shown in Figure 15, the intersection angle is 90°, but the intersection angle is not limited to 90°. In the example shown in Figure 16, the display device 1000l includes a fifth-embodied display unit 91a used as a HUD 42 and a sixth-embodied display unit 92b, and these fifth-embodied display unit 91a and sixth-embodied display unit 92b are arranged so that their respective optical paths intersect at the intersection (crossing point) PS1. In the example shown in Figure 16, the intersection angle is 90°, but the intersection angle is not limited to 90°.

[0125] Although embodiments of the present disclosure have been described in detail above, the present disclosure is not limited to the embodiments described above.

[0126] For example, the above describes a display device equipped with an image display unit, but is not limited to this. For example, the present disclosure may describe a device that does not have an image display unit but is equipped with an optical system. For example, the housing of a display device may have a mounting section on which an image display unit can be installed. The mounting section may be located on a part of the wall surface of the housing, on the inside of the housing, or inside the housing. In this case, the image display unit may be located on the inside of the housing or inside the housing. Also, the mounting section may be located on the outside of the housing or outside the housing. That is, the image display unit may be located on the outside of the housing or outside the housing. In this case, the housing may have an opening in which a part of the wall surface is cut out. The mounting section may be positioned relative to the housing so that the display light emitted from the image display unit installed in the mounting section is guided to the inside of the housing through the opening. The mounting section may be positioned relative to the housing so that the display light emitted from the image display unit installed in the mounting section is guided to the inside of the housing through the opening. The mounting section may be connected to the outer wall of the housing, or it may be connected to the outer wall of the housing in such a way that it closes at least a part of the opening. A light-transmitting member may be placed in the opening, and this member may be, for example, glass or resin. For example, Figure 1 shows a display device in which an image display unit is installed in the mounting section, but it may also be a device in which an image display unit is not installed in the mounting section. In this case, the device may be an image display unit housing device having a housing that includes a viewing section, an optical system, and a mounting section in which an image display unit can be installed. The configuration of the display device of each embodiment described above may also be realized in the image display unit housing device. That is, the position of the mounting section of the image display unit housing device may be defined so that when an image display unit is installed in the mounting section, it becomes the configuration of each embodiment described above. In addition, the housing of the image display unit housing device may have an opening, and the image display unit may be insertable through the opening. In this case, the image display unit housing device may have the same configuration as the display device, except that the housing has an opening and the image display unit can be inserted from the outside.

[0127] This application is based on Japanese Patent Application No. 2024-232921, filed on 27 December 2024, the contents of which are included in this application.

[0128] In order to express the present invention, the embodiments have been adequately and fully described above with reference to the drawings. However, those skilled in the art should recognize that it is easy to modify and / or improve upon the above embodiments. Therefore, unless such modifications or improvements implemented by those skilled in the art fall outside the scope of the claims, such modifications or improvements shall be considered to be included within the scope of the claims.

[0129] 1000a, 1000b, 1000d, 1000e Display device 10 (10a, 10b, 10c), 20 (20a, 20b, 20c), 30 (30a, 30b, 30c) Display unit

Claims

1. A display device comprising: a first display unit having a first image display unit for displaying a first image and a first optical system for forming a first image of the first image; and a second display unit having a second image display unit for displaying a second image, wherein the first and second display units are arranged so that their respective optical paths intersect.

2. The display device according to claim 1, wherein the second display unit is arranged such that the second optical path of the second image display unit intersects with the first optical path of the first image display unit within the first optical system.

3. The display device according to claim 1 or 2, wherein the second display unit further comprises a second optical system for forming an image of the second image, and the first and second display units are arranged such that their respective optical paths intersect within the first optical system and the second optical system.

4. The display device according to any one of claims 1 to 3, wherein the normals of the first and second display units intersect at one point.

5. The display device according to any one of claims 1 to 4, wherein the first and second display units are arranged such that the first distance from the viewer viewing the respective image to the first image on the first display unit and the second distance from the viewer to the second image on the second display unit are different.

6. The display device according to any one of claims 1 to 5, wherein the first and second display units are arranged so that, when viewed by a viewer, the first image of the first display unit and the second image of the second display unit are superimposed by at least one portion.

7. The display device according to any one of claims 1 to 4, wherein the first and second display units are arranged such that the first distance from a viewer viewing the respective image to the first image on the first display unit is equal to the second distance from the viewer to the second image on the second display unit.

8. The display device according to any one of claims 1 to 7, wherein at least one of the first and second display units further comprises a first modification unit that changes at least one of the distance from a viewer viewing the image to the image and the magnification, the first and second display units are mounted in a vehicle so that their respective image can be viewed by an occupant, and the first modification unit comprises a survey unit that examines at least one of the position and orientation of the seat in the vehicle, a first processing unit that determines a first modification amount based on at least one of the position and orientation examined by the survey unit, and a first implementation unit that changes at least one of the distance and magnification according to the first modification amount determined by the first processing unit.

9. The display device according to claim 8, wherein at least one of the distance and magnification is the distance, and at least one of the position and orientation is the position, and the first implement changes the distance to be longer than the initial distance in accordance with the first change amount if the position of the seat is the initial seat position and the distance is the initial distance, and changes the distance to be shorter than the initial distance in accordance with the first change amount if the first change amount is the amount that moves the seat away from the steering wheel from the initial seat position.

10. The display device according to claim 8, wherein at least one of the distance and magnification is the magnification, and at least one of the position and orientation is the position, and the first implement changes the magnification to be smaller than the initial magnification in accordance with the first change amount if the position of the seat is the initial seat position and the magnification is the initial magnification, and changes the magnification to be larger than the initial magnification in accordance with the first change amount if the first change amount is the amount that moves the seat away from the steering wheel from the initial seat position.

11. The display device according to any one of claims 1 to 10, wherein at least one of the first and second display units further comprises a second modifying unit that changes at least one of the distance from a viewer viewing the image to the image and the magnification based on the content displayed on the image.

12. The display device according to claim 11, wherein at least one of the distance and magnification is the distance, and the second modification unit modifies the distance to be shorter than the initial distance if the content includes content that prompts attention.

13. The display device according to claim 11, wherein at least one of the distance and magnification is the magnification, and the second modification unit changes the magnification to be greater than the initial magnification if the content includes content that prompts attention.

14. The display device according to any one of claims 1 to 13, further comprising an image control unit that controls each image displayed on the first and second display units, wherein the image control unit switches the images of the plurality of display units to each other.

15. The display device according to any one of claims 1 to 13, further comprising an image control unit for controlling each of the images displayed on the first and second display units, wherein the image control unit controls the first and second display units so that the images displayed on the first and second display units form a single image.

16. The display device according to any one of claims 1 to 13, further comprising an image control unit for controlling each image to be displayed on the first and second display units, wherein the image control unit controls the first and second display units to move an image from one to the other.

17. The display device according to any one of claims 1 to 13, further comprising an image control unit for controlling each image to be displayed on the first and second display units, wherein the image control unit controls the first and second display units to display a predetermined image on one of the first and second display units and not to display the predetermined image on the other.

18. The display device according to any one of claims 1 to 7, further comprising a third display unit having a third image display unit for displaying a third image, wherein the optical path of the third display unit is arranged to intersect with the optical path of at least one of the first and second image display units.

19. The display device according to any one of claims 1 to 7, further comprising a third display unit having a third image display unit for displaying a third image, wherein the first and second display units are arranged to be visible to a first viewer, and the third display unit is arranged to be visible to a second viewer different from the first viewer.

20. A vehicle equipped with a display device according to any one of claims 1 to 19.

21. A display system comprising a display device according to any one of claims 1 to 19, and a camera capable of communicating with the display device, wherein at least one of the first image display unit and the second image display unit displays an image captured by the camera.

22. A mobile body comprising the display system described in claim 21.

23. An image display unit housing device comprising: a first display unit having a first mounting section on which a first image display unit for displaying a first image can be installed; a first optical system for forming a first image of the first image; and a second display unit having a second mounting section on which a second image display unit for displaying a second image can be installed, wherein the first and second display units are arranged so that their respective optical paths intersect.

Images