Head-mounted display device

Abstract

To provide a head-mounted display device with a large eye box. [Solution] The head-mounted display device comprises an image forming element, a display optical system for displaying an image formed by the image forming element, a light guiding optical system for guiding light from the display optical system to the observer's eye, and a light-transmitting member positioned in front of the observer's eye. The image forming element, the display optical system, and the light guiding optical system are positioned on the side of the observer's eye that is located relative to the light-transmitting member in the observer's direct viewing direction.

Description

Technical Field

[0006] , , , , , , , , , ,

[0007]

[0001] The present invention relates to a head-mounted display device.

Background Art

[0002] A head-mounted display device such as VR (Virtual Reality) glasses or AR (Augmented Reality) glasses that is worn on an observer's head and displays an image observable by the observer is known.

[0003] For example, Patent Document 1 discloses a head-mounted display device having an eyepiece optical system that guides image light from a display element to an observer's eyeball to display an image.

Summary of the Invention

Problems to be Solved by the Invention

[0004] In However, in the device described in Patent Document 1, the eyebox, which means the range within which the observer can observe the displayed image, may be small.

[0005] In An object of the present invention is to provide a head-mounted display device with a large eyebox.

Means for Solving the Problems

[0006] A head-mounted display device according to an aspect of the present invention includes an image forming element, a display optical system that displays an image of the image formed by the image forming element, a light guiding optical system that guides light from the display optical system to an observer's eye, and a translucent member disposed in front of the observer's eyes, wherein the image forming element, the display optical system, and the light guiding optical system are disposed on the side of the observer's eye closer to the observer than the translucent member in the observer's line of sight.

Effects of the Invention

[0007] According to the present invention, it is possible to provide a head-mounted display device with a large eyebox. ​

[0008] [Figure 1] This is a schematic perspective view showing the head-mounted display device according to the first embodiment in a state where it is attached to the observer's head. [Figure 2] This is a schematic top view showing the overall configuration of a head-mounted display device according to the first embodiment. [Figure 3] This is a schematic perspective view showing the configuration around the base member of a head-mounted display device according to the first embodiment. [Figure 4] This is a schematic top view showing the configuration of the image forming element, display optical system, and light guide optical system in a head-mounted display device according to the first embodiment. [Figure 5] This is a schematic diagram showing an image displayed by a head-mounted display device according to the first embodiment. [Figure 6] This is a schematic diagram showing the configuration of the coupling part and base member of the head-mounted display device according to the first embodiment. [Figure 7] This is a schematic diagram showing how the image moves due to the coupling portion of the head-mounted display device according to the first embodiment. [Figure 8A] This is a schematic diagram showing a first example of how the image moves when the connected part is changed in a head-mounted display device according to the first embodiment. [Figure 8B] This is a schematic diagram showing a second example of how the image moves when the connected part is changed in the head-mounted display device according to the first embodiment. [Figure 8C] This is a schematic diagram showing a third example of how the image moves when the connected part is changed in a head-mounted display device according to the first embodiment. [Figure 9] This is a schematic top view showing the configuration of the image forming element, display optical system, and light guide optical system of a head-mounted display device according to the second embodiment. [Figure 10] This is a schematic diagram showing the first variable mechanism and the second variable mechanism of the head-mounted display device according to the third embodiment. [Modes for carrying out the invention]

[0009] A head-mounted display device according to an embodiment of the present invention will be described in detail with reference to the drawings. However, the embodiments shown below are illustrative of a head-mounted display device according to an embodiment of the present invention and are not limited thereto. Unless otherwise stated, the dimensions, materials, shapes, relative arrangements, etc. of the components described in the embodiments of the present invention are not intended to limit the scope of the embodiments of the present invention to only those embodiments, but are merely illustrative examples. The size, positional relationships, etc. of the members shown in each drawing may be exaggerated for clarity of explanation. In addition, in the following description, the same name and reference numerals indicate the same or similar members, and detailed explanations will be omitted as appropriate.

[0010] In the following explanation, the arrangement and configuration of each part may be described using the XYZ Cartesian coordinate system for clarity. The three axes in the XYZ Cartesian coordinate system are orthogonal to each other. In the XYZ Cartesian coordinate system, the direction in which the X axis extends is called the "X direction," the direction in which the Y axis extends is called the "Y direction," and the direction in which the Z axis extends is called the "Z direction." The direction in which the X-axis arrow points is denoted as the +X side, and the opposite side of the +X side is called the -X side. The direction in which the Y-axis arrow points is called the +Y side, and the opposite side of the +Y side is called the -Y side. The direction in which the Z-axis arrow points is called the +Z side, and the opposite side of the +Z side is called the -Z side.

[0011] The +Z direction corresponds, for example, to the direction of direct line of sight of an observer wearing a head-mounted display device according to an embodiment of the present invention. The direction of direct line of sight refers to the direction of the observer's gaze when looking straight ahead. The X direction corresponds to the direction along the optical axis of the display optical system of the head-mounted display device according to an embodiment of the present invention. The Y direction corresponds to the direction perpendicular to the X and Z directions, respectively.

[0012] However, the directional expressions above merely describe the relative positions, orientations, and directions, and do not necessarily correspond to the actual relationships in use. Furthermore, these directions are unrelated to the direction of gravity.

[0013] In the terms of the present specification and claims, the image includes not only still images but also moving images (videos), which may also be referred to as video images. In the terms of the present specification, parallel may include an inclination of ±10 degrees or less with respect to parallel. Also, orthogonal may include an inclination of ±10 degrees or less with respect to orthogonal.

[0014] [First Embodiment] <Configuration of the Head-Mounted Display Device According to the First Embodiment> (Overall Configuration) Referring to FIGS. 1 to 4, the head-mounted display device according to the first embodiment will be described. FIG. 1 is a schematic perspective view showing a state in which the head-mounted display device 100 according to the first embodiment is mounted on the head of the observer U. FIG. 2 is a schematic top view showing the overall configuration of the head-mounted display device 100. FIG. 3 is a schematic perspective view showing the configuration around the base member 9 in the head-mounted display device 100. FIG. 4 is a schematic top view showing the configurations of the image forming element 1, the display optical system 2, and the light guiding optical system 3 in the head-mounted display device 100. Note that FIG. 4 shows the image forming element 1, the display optical system 2, and the light guiding optical system 3 in a state where the light transmissive member 4, the base member 9, etc. are removed. FIG. 5 is a schematic diagram showing the image Im displayed by the head-mounted display device 100.

[0015] The head-mounted display device 100 includes an image forming element 1 and a display optical system 2 that displays an image formed by the image forming element 1. The head-mounted display device 100 also includes a light guiding optical system 3 that guides the light L1 from the display optical system to the eye E of the observer U, and a light transmissive member 4 disposed in front of the eye of the observer U. Here, "in front of the eye" refers to the front of the eye E of the observer U in the direct vision direction of the observer U. Also, from another perspective, "in front of the eye" refers to the position facing the eye E of the observer U in the direct vision direction of the observer U.

[0016] In the example shown in FIGS. 1 to 4, the head-mounted display device 100 includes a support member 5 that supports an image forming element 1, a display optical system 2, and a light guide optical system 3, and a control board 6 that controls image formation by the image forming element 1. Further, the head-mounted display device 100 includes a flexible wiring board 61 that electrically connects the image forming element 1 and the control board 6, and a glasses-type support 7 that supports each component of the head-mounted display device 100. In addition, the head-mounted display device 100 includes a coupling portion 8 that connects to the support member 5, and a base member 9 that includes a coupled portion that couples with the coupling portion 8.

[0017] The head-mounted display device 100 is a device that is worn on the head of an observer U and displays an image that can be observed by the observer U. From another perspective, the head-mounted display device 100 is a head-mounted display (HMD). In the example shown in FIG. 1, the head-mounted display device 100 is worn on the head of the observer U such that the observer U wears the glasses-type support 7.

[0018] In the example shown in FIG. 2, the light-transmissive member 4 is disposed on the frame 71 of the support 7. The control board 6 is disposed on the arm 72 of the support 7. In FIG. 2, in order to show that the support 7 includes the frame 71 and the arm 72, the reference numeral of the support 7 and the reference numerals of the frame 71 and the arm 72 are shown together. In the figures shown hereinafter, the reference numerals may be shown together for the same purpose.

[0019] In the present embodiment, the image forming element 1, the display optical system, and the light guide optical system 3 are disposed on the side where the eye E of the observer U is located rather than the light-transmissive member 4 in the straight-ahead direction of the observer U. In the example shown in FIG. 2, the image forming element 1, the display optical system 2, and the light guide optical system 3 are disposed between the light-transmissive member and the eye E of the observer U in the Z direction while being supported by the support member 5.

[0020] In the example shown in Figure 2, the image forming element 1 includes a light-emitting diode array element or an organic electroluminescent element. The image forming element 1 forms an image using light emitted from each pixel of the light-emitting diode array element or organic electroluminescent element. The display optical system 2 includes a triplet lens. The display optical system 2 displays a virtual image of the image formed by the image forming element 1. The light L1 constituting the virtual image exits the display optical system 2 and then enters the light guide optical system 3. The light guide optical system 3 includes a reflective mirror that reflects the light L1 from the display optical system 2 towards the observer U's eye E. The light L1 reflected by the reflective mirror of the light guide optical system 3 enters the observer U's eye E. As the light L1 enters the eye E, the observer U, wearing the head-mounted display device 100, can observe the virtual image displayed by the display optical system 2.

[0021] In the example shown in Figure 2, the reflective mirror of the light guide optical system 3 reflects a portion of the light L1 from the display optical system 2 toward the observer U's eye E, and also includes a partial reflective surface that transmits a portion of the ambient light L2 incident through the light-transmitting member 4 from the opposite side of where the observer U's eye E is located, relative to the light-transmitting member 4. As an example, the reflective mirror of the light guide optical system 3 is a half-mirror that includes a partial reflective surface that reflects approximately 50% of the incident visible light and transmits approximately 50%. The observer U can observe the external scenery through the light-transmitting member 4 placed on the support 7, and can also observe the virtual image displayed by the head-mounted display device 100 superimposed on the external scenery. In other words, the head-mounted display device 100 is a see-through type head-mounted display device.

[0022] In Figure 4, the coupling portion 8 is a part that changes the tilt and position of the support member 5, thereby changing the position of the image displayed by the head-mounted display device 100. The coupling portion 8 may be formed integrally with the support member 5, or it may be formed separately from the support member 5, as long as it is connected to the support member 5. The screw member 51 is a member used to support the image forming element 1 and the display optical system 2, etc., by the support member 5.

[0023] The base member 9 shown in Figure 3 is a member that holds the support member 5 and changes the tilt and position of the support member 5, thereby changing the position of the image displayed by the head-mounted display device 100. The base member 9 includes a frame portion 91 that holds the support member 5 on the inside when viewed from the normal viewing direction, a connected portion 92 provided on the inner surface of the frame portion 91 and including a connected portion, and a clamp portion 93 that fixes the connected portion 8 connected to the connected portion. The frame portion 91 is formed to be the size and shape that can be attached to the frame 71 of the spectacle-type support 7. The frame portion 91 is also a frame body that is open on the inside when viewed from the normal viewing direction. The frame portion 91 holds the support member 5 by fixing the support member 5 to its inner surface.

[0024] Figure 5 shows an example of an image Im displayed by the head-mounted display device 100. In the example shown in Figure 5, the image Im is a virtual image containing characters such as hiragana, kanji, and English letters, as well as symbols, figures, etc.

[0025] For example, an image signal, including characters such as hiragana, kanji, and English letters, as well as symbols and shapes, as shown in Figure 5, is transmitted from an image output device such as a smartphone or PC (Personal Computer) to the control board 6 of the head-mounted display device 100. The control board 6 converts the received image signal into image data having a resolution and orientation suitable for the head-mounted display device 100, and then outputs the image data to the image forming element 1. The image forming element 1 forms an image based on the image data input from the control board 6, and the display optical system 2 displays a virtual image of the image formed by the image forming element 1.

[0026] (Main effects and benefits of the head-mounted display device 100) In Figure 4, the exit pupil EP represents the exit pupil of the head-mounted display device 100. Observer U can observe the image displayed by the head-mounted display device 100 through the exit pupil EP. More specifically, when observer U views the exit pupil EP from the emmetropic direction, i.e., the +Z side, observer U can observe the image displayed by the head-mounted display device 100 in the area where the pupil PP of eye E, located on the -Z side of the exit pupil EP, overlaps with the exit pupil EP.

[0027] The range in which the observer U can observe the image displayed by the head-mounted display device 100 through the exit pupil EP is called the eye box. The smaller the eye box, the more likely the image displayed by the head-mounted display device 100 is to disappear in response to the movement of the observer U's eye E due to changes in gaze, etc. On the other hand, the larger the eye box, the easier it is to maintain an observable state of the image displayed by the head-mounted display device 100 even when the observer U moves their eye E.

[0028] The shorter the distance d between the exit pupil EP and the pupil PP, the larger the apparent size S of the exit pupil EP when viewed in the emmetropic direction. A larger apparent size S of the exit pupil EP means a larger overlap area between the pupil PP and the exit pupil EP, resulting in a larger eye box. The apparent size S of the exit pupil EP refers to the size obtained by multiplying the actual size of the exit pupil EP by the imaging magnification of the lens formed by the crystalline lens of the eye E. A shorter distance d results in a larger imaging magnification, thus increasing the apparent size S of the exit pupil EP. Conversely, a longer distance d results in a smaller imaging magnification, thus decreasing the apparent size S of the exit pupil EP.

[0029] Here, for example, in the head-mounted display device described in Patent Document 1, the light guide optical system and display optical system are arranged on the side opposite to the side where the eye is positioned relative to the light-transmitting member, and the exit pupil EP is formed on the side opposite to the side where the eye is positioned relative to the light-transmitting member. By forming the exit pupil EP on the side opposite to the side where the eye is positioned relative to the light-transmitting member, the distance d becomes longer compared to the case where the exit pupil EP is formed on the side where the eye is positioned. Due to the longer distance d, the apparent size S of the exit pupil EP when viewed in the emmetropic direction becomes smaller, and the eye box becomes smaller.

[0030] In this embodiment, the image forming element 1, the display optical system 2, and the light guide optical system 3 are positioned on the side of the observer U's eye E that is located relative to the light-transmitting member 4, in the direction of normal viewing for the observer U. This shortens the distance d compared to the case where the light guide optical system 3 and the display optical system 2 are positioned on the opposite side of the light-transmitting member 4 from the side where the eye E is located. As a result, in this embodiment, the apparent size S of the exit pupil EP is increased when the exit pupil EP is viewed in the direction of normal viewing, and a head-mounted display device 100 with a larger eye box can be provided.

[0031] The image forming element 1 includes a light-emitting diode array element or an organic electroluminescent element. The light-emitting diode array element or organic electroluminescent element forms an image by emitting light from multiple pixels. In Figure 4, the display surface 1a is the surface on which the image forming element 1 displays an image, and is the surface on which the pixels of the image forming element 1 are arranged in two dimensions.

[0032] Since the image forming element 1 emits light, a separate light source is not required. The elimination of a light source simplifies the configuration of the head-mounted display device 100. However, the image forming element 1 is not limited to including a light-emitting diode array element or an organic electroluminescent element. For example, the head-mounted display device 100 may have a light source, and the image forming element 1 may include an image modulator such as a liquid crystal panel or a scanning mirror.

[0033] The display optical system 2 is not limited to a triplet lens, and its configuration can be appropriately determined according to the specifications of the head-mounted display device 100. The display optical system 2 is not limited to lenses, but may also include mirrors, diffractive optical elements, etc. The lens of the display optical system 2 can be made up of a glass material or resin material that is transparent to visible light. The image displayed by the display optical system 2 may be a real image, not just a virtual image. The optical axis 2C shown by the dashed line in Figures 2 and 4 represents the optical axis of the display optical system 2.

[0034] The light-guiding optical system 3 includes a reflective mirror that reflects the light L1 from the display optical system 2 toward the observer U's eye E. This allows the light L1 from the display optical system 2 to be guided to the observer U's eye E with a simple and low-cost configuration, compared to using optical elements with complex shapes such as concave mirrors.

[0035] The reflective mirror in the light guide optical system 3 reflects a portion of the light L1 toward the observer U's eye E and includes a partially reflective surface that transmits a portion of the ambient light L2 incident through the light-transmitting member 4. This makes it possible to provide a see-through type head-mounted display device 100 with a large eye box EB.

[0036] The transmittance or reflectance of the reflective mirror in the light guide optical system 3 is not limited to approximately 50%, but can be changed as appropriate. The light guide optical system 3 is not limited to a planar mirror, but may also include a concave mirror, etc. Furthermore, the light guide optical system 3 may be composed of one or more optical elements such as mirrors and lenses. For the mirror in the light guide optical system 3, a reflective film such as a metal film or dielectric film can be provided on the surface of a substrate made of glass material or resin material, etc. The lens in the light guide optical system 3 can be made of glass material or resin material, etc. that is transparent to visible light.

[0037] The light-transmitting member 4 can be made up of a glass material or resin material that is transparent to visible light. The light-transmitting member 4 may be a lens with refractive power, or it may be a simple plate-shaped member without refractive power. The support 7 is not limited to the eyeglass type, but may take various forms such as a headgear type, hat type, or helmet type.

[0038] (Joint portion 8 and base member 9) The coupling portion 8 and base member 9 of the head-mounted display device 100 will be described in more detail with reference to Figures 6, 7, 8A, 8B, and 8C.

[0039] Figure 6 is a schematic diagram showing the configuration of the coupling part 8 and the base member 9 of the head-mounted display device 100. Figure 7 is a schematic diagram showing the movement of the image Im by the coupling part 8 of the head-mounted display device 100. Figure 8A is a schematic diagram showing the first example of the movement of the image Im due to a change in the coupled part 92 of the head-mounted display device 100. Figure 8B is a schematic diagram showing the second example of the movement of the image Im due to a change in the coupled part 92 of the head-mounted display device 100. Figure 8C is a schematic diagram showing the third example of the movement of the image Im due to a change in the coupled part 92 of the head-mounted display device 100.

[0040] In the example shown in Figure 6, the connecting portion 8 is a portion in which a spherical portion 82 is provided at the end of a columnar portion 81. The connected portion 92 of the base member 9 includes a front holder 921 and a rear holder 922 positioned behind the front holder 921 (for example, on the -Z side). The connected portion 92 also includes the gap between the front holder 921 and the rear holder 922, into which the spherical portion 82 of the connecting portion 8 can be fitted.

[0041] The connected portion 92 includes connected portion 92-1, connected portion 92-2, and connected portion 92-3. Connected portions 92-1, 92-2, and 92-3 are provided at different positions in the direction along the optical axis 2C of the display optical system 2 (for example, in the X direction). The coupling portion 8 connects to the connected portion 92 by fitting a spherical portion 82 to any one of connected portions 92-1, 92-2, or 92-3. The connected portion 92 is also detachably connected to the coupling portion 8.

[0042] The spherical portion 82 is rotatable while fitted into the connected portion 92. The rotation of the spherical portion 82 allows the inclination of the connected portion 8 with respect to the base member 9 to be changed.

[0043] In this embodiment, the head-mounted display device 100 has a variable tilt of the support member 5 with respect to a first axis along the optical axis 2C of the display optical system 2, and a second axis intersecting the first axis and the direction of direct viewing of the observer U. For example, the first axis is along the X axis, and the second axis is along the Y axis. For example, in the head-mounted display device 100, the tilt of the support member 5 is variable with respect to the first and second axes as the centers of rotation by changing the inclination of the connecting part 8 connected to the coupled part 92 with respect to the base member 9.

[0044] In the example shown in Figure 7, when the support member 5 is tilted in the direction of arrow B11 with the X-axis as the center of rotation, the image Im moves in the direction of arrow B12 along the Y-axis. When the support member 5 is tilted in the direction indicated by arrow B21 with the X-axis as the center of rotation, the image Im moves in the direction of arrow B22 along the Y-axis. When the support member 5 is tilted in the direction indicated by arrow B31 with the Y-axis as the center of rotation, the image Im moves in the direction of arrow B32 along the X-axis. When the support member 5 is tilted in the direction indicated by arrow B41 with the Y-axis as the center of rotation, the image Im moves in the direction of arrow B42 along the X-axis. In this way, the head-mounted display device 100 allows the position of the image Im observed by the observer U to be moved by changing the inclination of the coupling part 8 with respect to the base member 9.

[0045] Furthermore, in this embodiment, the position of the support member 5 in the direction along the optical axis 2C of the display optical system 2 is variable in the head-mounted display device 100. For example, the position of the support member 5 in the direction along the optical axis 2C of the display optical system 2 is variable in the head-mounted display device 100 by changing the coupled portion 92 to which the coupling portion 8 is coupled.

[0046] Figure 8A shows the state in which the spherical portion 82 of the coupling part 8 is coupled to the coupled part 92-1 in Figure 6. In this state, the light guide optical system 3 is located in the center of the field of view of the observer U who is looking directly at the device, and the image Im from the head-mounted display device 100 is displayed in the center of the field of view. The observer U can clearly observe the image Im displayed in the center of the field of view.

[0047] Figure 8B shows the state in which the spherical portion 82 of the coupling portion 8 is coupled to the coupled portion 92-2 in Figure 6. In this state, the light guide optical system 3 is positioned slightly off-X from the center of the field of view of the observer U who is looking directly at the observer. In other words, the light guide optical system 3 is positioned off-X compared to the state in Figure 8A. The image Im from the head-mounted display device 100 is displayed at a position slightly off-X from the center of the field of view. By being displayed at a position slightly off-X from the center of the field of view, the observer U's field of view is less obstructed by the image Im when looking directly at the observer compared to when it is displayed in the center of the field of view. The observer U can then observe the image Im displayed at that position by directing their gaze to the position slightly off-X from the center of the field of view when necessary.

[0048] Figure 8C shows the state in which the spherical portion 82 of the coupling portion 8 is coupled to the coupled portion 92-3 in Figure 6. In this state, the light guide optical system 3 is located at a position significantly shifted to the -X side from the center of the field of view of the observer U who is looking directly at the field of view. In other words, the light guide optical system 3 is located at a position further shifted to the -X side compared to the state in Figure 8B. The image Im from the head-mounted display device 100 is displayed at a position significantly shifted to the -X side from the center of the field of view. By being displayed at a position significantly shifted to the -X side from the center of the field of view, the observer U's field of view is less obstructed by the image Im in a normal viewing state compared to when it is displayed at a position slightly off-center from the field of view. The observer U can then observe the image Im displayed at that position by directing their gaze to the position significantly shifted to the -X side from the center of the field of view when necessary.

[0049] For example, the spherical portion 82 of the connecting portion 8 is connected to the connected portion 92, the tilt of the support member 5 is adjusted, and then the connecting portion 8 is fixed to the connected portion 92 by tightening the screw member that makes up the clamp portion 93.

[0050] As described above, in this embodiment, by changing the inclination of the connecting portion 8 with respect to the base member 9, the inclination of the support member 5 is changed with respect to the first axis and the second axis as the centers of rotation, and the position of the image Im displayed by the head-mounted display device 100 can be moved. As a result, the observer U can observe the image Im at a desired position.

[0051] Furthermore, in this embodiment, the base member 9 includes a plurality of coupling parts 92. The plurality of coupling parts 92 are provided at different positions in the direction along the optical axis 2C of the display optical system 2. By changing the coupling parts 92 to which the coupling part 8 is coupled, the position of the support member 5 in the direction along the optical axis 2C of the display optical system 2 is variable. By changing the position of the support member 5 in the direction along the optical axis 2C, the position of the image Im displayed by the head-mounted display device 100 can be moved. As a result, the observer U can observe the image Im at a desired position.

[0052] [Second Embodiment] Next, a head-mounted display device according to the second embodiment will be described. Note that names and reference numerals identical to those used in the previously described embodiments indicate the same or identical components or configurations, and detailed explanations will be omitted as appropriate. This also applies to the embodiments described later.

[0053] Figure 9 is a schematic top view showing the configuration of the image forming element 1, display optical system 2, and light guide optical system 3 of the head-mounted display device according to the second embodiment.

[0054] As shown in Figure 9, this embodiment differs from the head-mounted display device 100 according to the first embodiment in that the light guide optical system 3 includes planar mirrors 3-1, 3-2, and 3-3, each having a reflective surface 30.

[0055] In the example shown in Figure 9, the reflective surface 30 includes reflective surface 30-1, reflective surface 30-2, and reflective surface 30-3. Planar mirror 3-1 has reflective surface 30-1, planar mirror 3-2 has reflective surface 30-2, and planar mirror 3-3 has reflective surface 30-3.

[0056] In this embodiment, the planar mirrors 3-1, 3-2, and 3-3 are arranged such that the reflective surfaces 30-1, 30-2, and 30-3 do not overlap when viewed from a direction along the optical axis 2C of the display optical system 2, and do not overlap when viewed along the observer U's normal viewing direction (e.g., the Z direction). This arrangement increases the size S of the exit pupil EP formed by the light L1 reflected by the reflective surfaces 30-1, 30-2, and 30-3.

[0057] In the example shown in Figure 9, the planar mirrors 3-1, 3-2, and 3-3 are arranged such that their reflective surfaces 30-1, 30-2, and 30-3 are each tilted at 45 degrees with respect to the optical axis 2C. By arranging the reflective surfaces 30-1, 30-2, and 30-3 so that they do not overlap when viewed from a direction along the optical axis 2C and do not overlap when viewed along the observer U's normal viewing direction, the exit pupil EP expands in the direction along the optical axis 2C, and its size S increases. In this embodiment, the larger size S of the exit pupil EP increases the overlapping area between the pupil PP and the exit pupil EP, thereby increasing the size of the eye box.

[0058] [Third Embodiment] Next, a head-mounted display device according to the third embodiment will be described.

[0059] Figure 10 is a schematic diagram showing the first variable mechanism 31 and the second variable mechanism 32 of the head-mounted display device according to the third embodiment.

[0060] As shown in Figure 10, the head-mounted display device according to this embodiment differs from the head-mounted display device 100 according to the first embodiment in that it has a first variable mechanism 31 and a second variable mechanism 32.

[0061] The first variable mechanism 31 is a mechanism that changes the distance between the image forming element 1 and the display optical system in a direction along the optical axis 2C of the display optical system. In the example shown in Figure 10, the first variable mechanism 31 includes a compression spring 311 that applies a biasing force to the light guide optical system 3 away from the image forming element 1 in a direction along the optical axis 2C, an intermediate member 312 that receives the biasing force from the compression spring 311, and a pressing member 313 that maintains the posture of the display optical system while receiving the biasing force from the compression spring 311 via the intermediate member 312. The pressing member 313 is, for example, a screw member.

[0062] The head-mounted display device according to this embodiment has a first variable mechanism 31, which allows the distance between the display optical system and the image forming element 1 in the direction along the optical axis 2C to be changed, thereby changing the distance between the observer's eye and the image.

[0063] For example, an observer with nearsightedness or other conditions that makes it difficult to see distant objects can manually drive the first variable mechanism 31 to shorten the distance between the display optical system and the image forming element 1. This brings the image closer to the observer's eye, making it easier for the observer to see the image. Conversely, an observer with farsightedness or other conditions that makes it difficult to see near objects can manually drive the first variable mechanism 31 to lengthen the distance between the display optical system and the image forming element 1. This moves the image further away from the observer's eye, making it easier for the observer to see the image. In this embodiment, the focus of the image can be adjusted by changing the distance between the display optical system and the image forming element 1 in the direction along the optical axis 2C, according to the observer's visual acuity. Note that the driving of the first variable mechanism 31 is not limited to manual operation by the observer, but may also be performed by a drive unit such as a motor.

[0064] Furthermore, in this embodiment, the display surface 1a of the image forming element 1 shown in Figure 4 above is perpendicular to the optical axis 2C, and the second variable mechanism 32 changes the relative position of the image forming element 1 with respect to the optical axis 2C in a virtual plane parallel to the display surface 1a of the image forming element 1.

[0065] In the example shown in Figure 10, the second variable mechanism 32 includes a push screw 320. The image forming element 1 is supported by the bracket 11. The display optical system and the light guide optical system 3 are supported by the optical system support member 5a. The observer can manually rotate the push screw 320 to drive the second variable mechanism 32. The optical system support member 5a can be pressed by the push screw 320 of the second variable mechanism 32, thereby changing its relative position in the Z direction with respect to the bracket 11 in a virtual plane parallel to the display surface 1a of the image forming element 1. With this configuration, the head-mounted display device according to this embodiment can finely adjust the displayed image in the Z direction.

[0066] In the example shown in Figure 10, the relative position of the display optical system and light guide optical system 3 and the image forming element 1 in the Z direction is changed within a virtual plane parallel to the display surface of the image forming element 1. However, the head-mounted display device according to this embodiment may change the relative position of the display optical system and light guide optical system 3 and the image forming element 1 in the Y direction within a virtual plane parallel to the display surface of the image forming element 1. Furthermore, the driving of the second variable mechanism 32 is not limited to manual operation by the observer, but may be performed by a drive unit such as a motor.

[0067] Although preferred embodiments have been described in detail above, the present invention is not limited to the embodiments described above, and various modifications and substitutions can be made to the embodiments described above without departing from the scope of the claims.

[0068] The ordinal numbers, quantities, and other figures used in the description of the embodiments of the present invention are all illustrative to specifically illustrate the technology of the present invention, and the present invention is not limited to these illustrative figures. Furthermore, the connection relationships between the components are illustrative to specifically illustrate the technology of the present invention, and do not limit the connection relationships that realize the functions of the present invention.

[0069] Examples of the present invention are as follows: <1> A head-mounted display device comprising an image forming element, a display optical system for displaying an image formed by the image forming element, a light guiding optical system for guiding light from the display optical system to the observer's eye, and a light-transmitting member positioned in front of the observer's eye, wherein the image forming element, the display optical system, and the light guiding optical system are positioned on the side of the observer's eye that is located relative to the light-transmitting member in the observer's direct viewing direction. <2> The light guide optical system includes a reflective mirror that reflects light from the display optical system toward the observer's eye. <1> This is a head-mounted display device as described above. <3> The reflective mirror includes a partial reflective surface that reflects a portion of the light from the display optical system toward the observer's eye, and transmits a portion of the ambient light incident through the light-transmitting member from the side opposite to the side where the observer's eye is located relative to the light-transmitting member. <2> This is a head-mounted display device as described above. <4> The tilt of the support member is variable with respect to each of the following axes as the center of rotation: a first axis along the optical axis of the display optical system, and a second axis intersecting the first axis and the direction of direct viewing of the observer. <1> from the above <3> It is a head-mounted display device as described in any one of the following. <5> The system includes a support member that supports the image forming element, the display optical system, and the light guide optical system, a coupling portion that is directly or indirectly connected to the support member, and a base member that includes a coupled portion that is coupled to the coupling portion, wherein the tilt of the support member is variable by changing the inclination of the coupling portion coupled to the coupled portion with respect to the base member, <4> This is a head-mounted display device as described above. <6> The position of the support member in the direction along the optical axis of the display optical system is variable, <1> from the above <5> It is a head-mounted display device as described in any one of the following. <7> The system comprises a support member that supports the image forming element, the display optical system, and the light guide optical system, a coupling portion connected to the support member, and a base member including a coupled portion that is coupled to the coupling portion, wherein the base member includes a plurality of coupled portions, each provided at different positions in the direction along the optical axis of the display optical system, the coupled portions are detachably coupled to the coupling portion, and the position of the support member in the direction along the optical axis of the display optical system is variable by changing the coupled portion to which the coupling portion is coupled. <6> This is a head-mounted display device as described above. <8> The light guide optical system includes a plurality of planar mirrors, each having a reflective surface, and the plurality of planar mirrors are arranged such that the plurality of reflective surfaces do not overlap when viewed from a direction along the optical axis of the display optical system, and do not overlap when viewed along the direction of the observer's direct line of sight. <1> from the above <7> It is a head-mounted display device as described in any one of the following. <9> The first variable mechanism has a first variable mechanism that changes the distance between the image forming element and the display optical system in a direction along the optical axis of the display optical system, <1> from the above <8> It is a head-mounted display device as described in any one of the following. <10> The display surface of the image forming element has a second variable mechanism that changes the relative position of the image forming element with respect to the optical axis in a virtual plane that is perpendicular to the optical axis of the display optical system and parallel to the display surface. <1> from the above <9> It is a head-mounted display device as described in any one of the following. <11> The image forming element includes a light-emitting diode array element or an organic electroluminescent element. <1> from the above <10> It is a head-mounted display device as described in any one of the following. [Explanation of symbols]

[0070] 1 Image forming element 1a Display surface 2 Display optical system 2C optical axis 3, 3a Light guiding optical system 3-1, 3-2, 3-3 Flat mirror 4 Translucent material 5. Support Member 5a Optical system support member 6. Control board 7 Support 8 Joint 9 main components 11 brackets 30, 30-1, 30-2, 30-3 reflective surface 31. First Variable Mechanism 32. Second Variable Mechanism 51 Screw component 61 Flexible Wiring Board 71 frames 72 Cranes 81 Columnar part 82 Spherical part 91 Frame section 92 Joined part 92-1, 92-2, 92-3 Connected part 93 Clamp section 100 Head-mounted display devices 311 Compression Spring 312 Intermediate member 313 Pressing member 320 Set screws 811, 812, 821, 822, 831, 832, 841, 842 Arrows 921 Front holder 922 Rear holder d distance E-eye EP exit pupil Im statue L1 light L2 ambient light PP Pupil Size S U Observer [Prior art documents] [Patent Documents]

[0071] [Patent Document 1] Patent No. 6399792

Claims

1. Image forming element and A display optical system for displaying the image of the image formed by the image forming element, A light guide optical system that directs light from the display optical system to the observer's eye, It comprises a light-transmitting member placed in front of the observer's eyes, A head-mounted display device wherein the image forming element, the display optical system, and the light guide optical system are arranged in the direction of the observer's direct line of sight, on the side of the light-transmitting member where the observer's eye is located.

2. The head-mounted display device according to claim 1, wherein the light-guiding optical system includes a reflective mirror that reflects light from the display optical system toward the observer's eye.

3. The head-mounted display device according to claim 2, wherein the reflective mirror reflects a portion of the light from the display optical system toward the observer's eye and includes a partial reflective surface that transmits a portion of the ambient light incident through the light-transmitting member from the side opposite to the side where the observer's eye is located relative to the light-transmitting member.

4. The system includes a support member that supports the image forming element, the display optical system, and the light guide optical system, The head-mounted display device according to claim 1, wherein the inclination of the support member is variable with respect to a first axis along the optical axis of the display optical system and a second axis intersecting the first axis and the direction of direct viewing of the observer, respectively, as the axis of rotation.

5. A connecting portion that is directly or indirectly connected to the support member, It has a base member including a connected portion that connects to the aforementioned connecting portion, The head-mounted display device according to claim 4, wherein the inclination of the support member is variable by changing the inclination of the connecting portion connected to the connected portion with respect to the base member.

6. The system includes a support member that supports the image forming element, the display optical system, and the light guide optical system, The head-mounted display device according to claim 1, wherein the position of the support member in the direction along the optical axis of the display optical system is variable.

7. The connecting portion that connects to the support member, It has a base member including a connected portion that connects to the aforementioned connecting portion, The base member includes a plurality of connected portions, each provided at different positions in the direction along the optical axis of the display optical system, The connected portion is detachably connected to the connecting portion. The head-mounted display device according to claim 6, wherein the position of the support member in the direction along the optical axis of the display optical system is variable by changing the connected portion to which the connecting portion is connected.

8. The aforementioned light guide optical system includes a plurality of planar mirrors, each having a reflective surface. The head-mounted display device according to claim 1, wherein the plurality of planar mirrors are arranged such that the plurality of reflective surfaces do not overlap when viewed from a direction along the optical axis of the display optical system, and do not overlap when viewed along the direction of the observer's direct line of sight.

9. The head-mounted display device according to claim 1, further comprising a first variable mechanism for changing the distance between the image forming element and the display optical system in a direction along the optical axis of the display optical system.

10. The display surface of the image forming element is perpendicular to the optical axis of the display optical system. The head-mounted display device according to claim 1, further comprising a second variable mechanism for changing the relative position of the image forming element with respect to the optical axis in a virtual plane parallel to the display surface.

11. The head-mounted display device according to claim 1, wherein the image forming element includes a light-emitting diode array element or an organic electroluminescent element.

Images