Optical device, image display device and display device

Abstract

An optical device 10 is provided, including: a first light guide plate 21, a first deflection unit 30 including three deflection members 31, 32, and 33, a second light guide plate 22, and a first deflection unit 40 including three deflection members 41, 42, and 43. A portion of light emitted from an image forming device is incident on the first deflection members 31 and 41, and the light is emitted from the third deflection members 33 and 43 via the light guide plates 21 and 22 and the second deflection members 32 and 42, and when a propagation direction of light deflected by the second deflection member 32 in the first light guide plate 21 is a first direction and a propagation direction of light deflected by the second deflection member 42 in the second light guide plate 22 is a second direction, the first direction is not parallel to the second direction and is opposite to the second direction.

Description

Technical Field

[0001] The present disclosure relates to an optical device, an image display device having the optical device, a display device having the image display device, and more particularly, to a display device for a head mounted display (HMD). Background Art

[0002] In recent years, the development of a head-mounted display (HMD) that displays an image from an image forming device on an optical device placed in front of an observer has been enthusiastically promoted. However, although various types of head-mounted displays are being studied, in order to provide a more realistic image for the head-mounted display, it is strongly required to further widen the viewing angle of the displayed image. In order to meet this demand, for example, a head-mounted display in which three deflection means are arranged on a light guide plate constituting an optical device is known from U.S. Patent Publication 2006 / 0132914A1 or U.S. Patent Publication 2014 / 0330966A1.

[0003] Furthermore, Japanese Patent Application Publication No. 2009-133998 discloses an image display device including:

[0004] (A) An image forming device having a plurality of pixels arranged in a two-dimensional matrix.

[0005] (B) a collimating optical system that causes light emitted from pixels of an image forming device to become parallel light, and

[0006] (C) an optical device that incident, guides, and emits light through a collimating optical system to become a plurality of parallel lights having different traveling directions,

[0007] Among them, optical equipment includes:

[0008] (a) a light guide plate in which incident light propagates internally by total reflection and is then emitted,

[0009] (b) a first diffraction grating member including a reflective volume hologram diffraction grating and arranged on the light guide plate, the reflective volume hologram diffraction grating diffracting and reflecting light incident on the light guide plate so that the light incident on the light guide plate is totally reflected within the light guide plate, and

[0010] (c) a second diffraction grating member composed of a reflective volume hologram diffraction grating arranged on the light guide plate, the reflective volume hologram diffraction grating diffracting and reflecting light propagating in the light guide plate by total reflection and emitting the light from the light guide plate,

[0011] When the normal line of the first diffraction grating member passing through the origin with the center of the first diffraction grating member as the origin (where the direction toward the collimating optical system side is the positive direction) is the Xi axis and the axis of the light guide plate passing through the origin and orthogonal to the Xi axis (where the direction toward the second diffraction grating member side is the positive direction) is the Yi axis,

[0012] The central light emitted from the central pixel of the image forming device and passing through the center of the collimating optical system is optically parallel to the X i Y i plane and at an acute angle to X i Z i Plane intersection.

[0013] Citation List

[0014] Patent Documents

[0015] Patent document 1: US Patent Publication No. 2006 / 0132914A1

[0016] Patent Document 2: U.S. Patent Publication No. 2014 / 0330966A1

[0017] Patent Document 3: Japanese Patent Application Publication No. 2009-133998 Summary of the invention

[0018] Problems to be solved by the present invention

[0019] However, the head mounted displays disclosed in the above two US patent publications cannot meet the demand for further expanding the viewing angle of the displayed image. In addition, since the image display device disclosed in Japanese Patent Application Publication No. 2009-133998 has only two diffraction grating components, namely, a first diffraction grating component and a second diffraction grating component, the displayed image area can be enlarged in the light guide plate only in one direction of propagation from the first diffraction grating to the second diffraction grating.

[0020] Therefore, an object of the present disclosure is to provide an optical device having a configuration and structure capable of further widening the viewing angle of a displayed image, an image display device including such an optical device, and a display device including such an image display device.

[0021] Solution to the problem

[0022] The optical device of the present disclosure for achieving the above-mentioned object is an optical device for incident, guiding and emitting light emitted from an image forming device, the optical device comprising a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate,

[0023] The first deflection unit includes a first A deflection component, a first B deflection component and a first C deflection component.

[0024] The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member,

[0025] A portion of the light emitted from the image forming device is incident on the first A deflecting member,

[0026] The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer,

[0027] at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member,

[0028] The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and

[0029] When the propagation direction of light deflected by the first B deflection component in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of light deflected by the second B deflection component in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction.

[0030] An image display device of the present disclosure for achieving the above-mentioned object is an image display device including an optical forming device and an optical device that incidents, guides, and emits light emitted from the image forming device, wherein the optical device includes the optical device of the present disclosure.

[0031] The display device of the present disclosure for achieving the above-mentioned purpose is a display device including a frame attached to the head of an observer and an image display device attached to the frame, wherein the image display device includes an image forming device and an optical device for incident, guiding and emitting light emitted from the image forming device, and the optical device includes the optical device of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1A and Figure 1B Schematic diagrams of a first light guide plate and a first deflecting unit and a second light guide plate and a second deflecting unit constituting the optical device of the first embodiment, respectively.

[0033] Figure 2A and Figure 2BThey are schematic diagrams of the arrangement of a first A deflecting element, a first B deflecting element, and a first C deflecting element constituting the optical apparatus of the first embodiment, and conceptual diagrams of wave vectors and the like of the first A deflecting element, the first B deflecting element, and the first C deflecting element, respectively.

[0034] Figure 3A and Figure 3B is a schematic cross-sectional view of an optical device of a first embodiment, Figure 3C is a schematic diagram of the optical device viewed from the side.

[0035] Figure 4 It is a schematic diagram of the optical device of the first embodiment viewed from above.

[0036] Figure 5 is a schematic diagram of the display device of the first embodiment viewed from the front.

[0037] Fig. 6A , Figure 6B and Figure 6C is a conceptual diagram of the image forming apparatus in the display apparatus of the first embodiment.

[0038] Figure 7 1 is a conceptual diagram showing the arrangement of an image forming apparatus, a light guide plate, a first A deflecting member, a second A deflecting member, and the like in the optical apparatus of the first embodiment.

[0039] Fig. 8A and Figure 8B 1 is a schematic diagram showing a first-stage arrangement of a first light guide plate and a first deflecting unit, and a second light guide plate and a second deflecting unit constituting the optical device of the first embodiment.

[0040] Fig.9A and Fig. 9B They are respectively a schematic diagram of the first stage arrangement of the first A deflection unit, the first B deflection unit and the first C deflection unit constituting the optical device of the first embodiment and a conceptual diagram of the wave vectors etc. of the first A deflection unit, the first B deflection unit and the first C deflection unit in the first stage arrangement.

[0041] Fig. 10A and Fig. 10B : is a schematic diagram showing a second-stage arrangement of the first light guide plate and the first deflecting unit constituting the optical device of the first embodiment.

[0042] Fig.11A and Fig. 11B They are respectively a schematic diagram of the second stage arrangement of the first A deflection unit, the first B deflection unit and the first C deflection unit constituting the optical device of the first embodiment, and a conceptual diagram of the wave vectors etc. of the first A deflection unit, the first B deflection unit and the first C deflection unit in the second stage arrangement.

[0043] Fig. 12A and Fig. 12B : is a schematic diagram showing a second-stage arrangement of the first light guide plate and the first deflecting unit constituting the optical device of the first embodiment.

[0044] Fig.13 is a schematic diagram of a first light guide plate and a first deflecting unit constituting the optical device of the second embodiment.

[0045] Fig.14 is a schematic diagram of a second light guide plate and a second deflecting unit constituting the optical device of the second embodiment.

[0046] Fig.15A , Fig. 15B , Fig. 15C , Fig.15D , Fig.15E , Fig.15F , Figure 15G and Fig.15H This is a conceptual diagram of a modified example of the optical device of the first embodiment.

[0047] Fig.16A and 16B : is a diagram showing simulation results of an image area obtained in the optical apparatus of the first embodiment.

[0048] Fig.17 : is a diagram showing simulation results of an image area obtained in the optical apparatus of the first embodiment.

[0049] Fig.18A and Fig.18B They are diagrams respectively showing simulation results of light propagation states in the first light guide plate and the second light guide plate obtained in the optical device of the first embodiment.

[0050] Fig.19A and Fig.19B are diagrams showing simulation results of images obtained by the first deflection unit and the second deflection unit, respectively, which are obtained in the optical apparatus of the first embodiment.

[0051] Fig. 20 is shown for obtaining Fig.16A , Fig. 16B and Fig.17 FIG. 2 is a schematic diagram of an arrangement state of a first A deflection unit, a first B deflection unit, and a first C deflection unit constituting a first deflection unit, showing a simulation result.

[0052] Fig.21 : is a diagram showing the relationship between the incident angle of light on the first A deflection element or the second A deflection element and the diffraction angle of the first A deflection element or the second A deflection element, with the pitch d as a parameter.

[0053] Fig.22A , Fig. 22B and Fig. 22C is a diagram for explaining an XYZ Cartesian coordinate system and a (x0, y0, z0) Cartesian coordinate system. DETAILED DESCRIPTION

[0054] Hereinafter, the present disclosure will be described based on the embodiments with reference to the drawings, but the present disclosure is not limited to the examples, and various numerical values ​​and materials in the examples are examples. Note that the description will be made in the following order.

[0055] 1. General Description of the Optical Device, Image Display Device, and Display Device of the Present Disclosure

[0056] 2. First Embodiment (Optical Device, Image Display Device, and Display Device of the Present Disclosure)

[0057] 3. Second Embodiment (Modification of the First Embodiment)

[0058] 4. Others

[0059] <General Description of Optical Device, Image Display Device, and Display Device of the Present Disclosure>

[0060] In the optical device of the present disclosure, the optical device constituting the image display device of the present disclosure, and the optical device constituting the display device of the present disclosure (hereinafter, these may be collectively referred to as "optical devices of the present disclosure, etc."), a configuration in which the first light guide plate and the second light guide plate are juxtaposed may be adopted. That is, a configuration in which the first light guide plate and the second light guide plate are separated and arranged in parallel with, for example, an air layer interposed therebetween may be adopted.

[0061] In the optical device and the like of the present disclosure including the above-described preferred configuration, the following mode may be adopted, wherein:

[0062] The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin,

[0063] In the XYZ Cartesian coordinate system through the origin,

[0064] When the axis including the bisector toward the first direction is the +X axis (the bisector is the bisector of the acute angle within the angle between the straight line passing through the origin and parallel to the first direction and the straight line passing through the origin and parallel to the second direction),

[0065] The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and

[0066] When the axis orthogonal to the X-axis and the Z-axis is the Y-axis,

[0067] The first deflection unit and the second deflection unit are arranged at positions symmetrical with respect to the YZ plane.

[0068] The first direction, which is the direction of the propagation direction of the light deflected by the first B deflection member in the first light guide plate when orthogonally projected onto the first light guide plate, extends in the +X axis direction but is not parallel to or parallel to the +X axis, and the second direction, which is the direction of the propagation direction of the light deflected by the second B deflection member in the second light guide plate when orthogonally projected onto the first light guide plate, extends in the -X axis direction but is not parallel to or parallel to the -X axis. That is, the first direction and the second direction are not parallel to each other or on the same straight line. A mode can be adopted in which the first A deflection member and the second A deflection member are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape, or have different shapes. Similarly, a mode can be adopted in which the first B deflection member and the second B deflection member are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape, or have different shapes, and the first C deflection member and the second C deflection member are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape, or have different shapes.

[0069] In the above-mentioned preferred modes of the optical device and the like of the present disclosure, the following configuration may be adopted, wherein:

[0070] The first deflection unit is arranged in a state of being rotated in a first rotation direction in a counterclockwise direction or a clockwise direction around the Z axis, and

[0071] The second deflection unit is arranged in a state of rotating around the Z axis in the second rotation direction in the clockwise direction or the counterclockwise direction. Then, in this case, a mode can be adopted in which when the rotation angle in the first rotation direction is and the rotation angle in the second rotation direction is hour,

[0072] satisfy Furthermore, a model may be adopted in which:

[0073]

[0074] Preferably,

[0075]

[0076] Note that the wave vectors of the first A deflection unit, the first B deflection unit and the first C deflection unit constituting the first deflection unit may be in a state of rotating in the first rotation direction, instead of arranging the first deflection unit in a state of rotating in the first rotation direction, and the wave vectors of the second A deflection unit, the second B deflection unit and the second C deflection unit constituting the second deflection unit may be in a state of rotating in the second rotation direction, instead of arranging the second deflection unit in a state of rotating in the second rotation direction.

[0077] Furthermore, in the above-mentioned various preferred modes of the optical device and the like of the present disclosure, when the angle formed by the direction of light incident on the first B deflection member and the direction of light emitted from the first B deflection member is ψ1 and the angle formed by the direction of light incident on the second B deflection member and the direction of light emitted from the second B deflection member is ψ2, it is satisfied that:

[0078] 90 degrees < ψ1, and

[0079] 90 degrees < ψ2

[0080] Additionally, a model may be employed in which:

[0081] Satisfies 90 degrees < ψ1 ≤ 105 degrees, and

[0082] 90 degrees < ψ2 ≤ 105 degrees,

[0083] Preferably,

[0084] Satisfies 90 degrees < ψ1 ≤ 100 degrees, and

[0085] 90 degrees < ψ2 ≤ 100 degrees

[0086] Additionally, a model may be employed in which:

[0087] Satisfies ψ1=ψ2,

[0088] Specifically, but not limited to:

[0089] Satisfy 99.5 (degrees) ≤ ψ1 = ψ2 ≤ 100.5 (degrees)

[0090] Furthermore, in the above-mentioned various preferred modes of the optical device etc. disclosed in the present invention, a mode can be adopted in which the orthogonal projection image of the first B deflection member when the first B deflection member is orthogonally projected onto the first light guide plate and the orthogonal projection image of the second B deflection member when the second B deflection member is orthogonally projected onto the first light guide plate partially overlap (in some cases, touch) and further, a mode can be adopted in which the end of the orthogonal projection image of the first B deflection member in the +X axis direction and the end of the orthogonal projection image of the second B deflection member in the -X axis direction overlap (in some cases, the end of the orthogonal projection image of the first B deflection member in the +X axis direction and the end of the orthogonal projection image of the second B deflection member in the -X axis direction touch). Therefore, by partially overlapping the orthogonal projection image of the first B deflection member when the first B deflection member is orthogonally projected onto the first light guide plate and the orthogonal projection image of the second B deflection member when the second B deflection member is orthogonally projected onto the first light guide plate, it is possible to reliably prevent the occurrence of cutting in the image at the center of the image. In addition, a mode can be adopted in which the orthogonal projection image of the first C deflection component when the first C deflection component is orthogonally projected onto the first light guide plate and the orthogonal projection image of the second C deflection component when the second C deflection component is partially orthogonally projected onto the first light guide plate partially overlap (in some cases, touch) and further, a mode can be adopted in which the end of the orthogonal projection image of the first C deflection component in the -X-axis direction and the end of the orthogonal projection image of the second C deflection component in the +X-axis direction overlap (in some cases, the end of the orthogonal projection image of the first C deflection component in the -X-axis direction and the end of the orthogonal projection image of the second C deflection component in the +X-axis direction touch) . In addition, a mode can be adopted in which the orthogonal projection image of the first A deflection component when the first A deflection component is orthogonally projected onto the first light guide plate and the orthogonal projection image of the second A deflection component when the second A deflection component is orthogonally projected onto the first light guide plate partially overlap (in some cases, touch) and further, a mode can be adopted in which the end of the orthogonal projection image of the first A deflection component in the +X-axis direction and the end of the orthogonal projection image of the second A deflection component in the -X-axis direction overlap (in some cases, the end of the orthogonal projection image of the first A deflection component in the +X-axis direction and the end of the orthogonal projection image of the second A deflection component in the -X-axis direction touch) .

[0091] Furthermore, among the above-mentioned various preferred modes of the optical device and the like of the present disclosure, a mode may be adopted in which:

[0092] The first A deflection element and the second A deflection element include volume holographic diffraction gratings, and

[0093] When the wave vector of the first A deflection element is k v 1-A , k v 1-A The X, Y, and Z components are k X 1-A , kY 1-A and k Z 1-A , the wave vector of the second A deflection element is k v 2-A And k v 2-A The X, Y, and Z components are k X 2-A , k Y 2-A and k Z 2-A hour,

[0094] Satisfy k X 1-A +k X 2-A =0,

[0095] k Y 1-A =k Y 2-A ,as well as

[0096] k Z 1-A =k Z 2-A

[0097] And, in this case, a pattern can be adopted where:

[0098] The first C-deflection element and the second C-deflection element include volume holographic diffraction gratings, and

[0099] When the wave vector of the first C deflection element is k v 1-C , k v 1-C The X, Y, and Z components are k X 1-C , k Y 1-C , k Z 1-C , the wave vector of the second C deflection element is k v 2-C And k v 2-C The X, Y, and Z components are k X 2-C , k Y 2-C , k Z 2-C hour,

[0100] Satisfy k X 1-C +k X 2-C=0,

[0101] k Y 1-C =k Y 2-C ,as well as

[0102] k Z 1-C =k Z 2-C

[0103] Alternatively, a model may be employed in which:

[0104] The first B deflection element and the second B deflection element include volume holographic diffraction gratings, and

[0105] When the wave vector of the first B deflection element is k v 1-B , k v 1-B The X, Y, and Z components are k X 1-B , k Y 1-B , k Z 1-B , the wave vector of the second B deflection element is k v 2-B And k v 2-B The X, Y, and Z components are k X 2-B , k Y 2-B , k Z 2-B hour,

[0106] Satisfy k X 1-B +k X 2-B =0,

[0107] k Y 1-B =k Y 2-B ,as well as

[0108] k Z 1-B =k Z 2-C

[0109] Alternatively, a model may be employed in which:

[0110] Satisfy k v 1-A +k v 1-B +kv 1-C = 0, and

[0111] k v 2-A +k v 2-B +k v 2-C =0

[0112] Then, the light incident on the first A deflection member and the second A deflection member and the light emitted from the first C deflection member and the second C deflection member therefore have a conjugate relationship. Note that, as described above, a vector is represented by a superscript letter "v", and, as described above, the X, Y, and Z components of a vector are represented by superscript letters "X", "Y", and "Z".

[0113] The volume holographic diffraction grating may be a transmission type or a reflection type, although this depends on the arrangement state of the first A deflection member, the first B deflection member and the first C deflection member and the second A deflection member, the second B deflection member and the second C deflection member with respect to the light guide plate. The volume holographic diffraction grating means a holographic diffraction grating that diffracts only +1 order diffraction light.

[0114] Furthermore, in the optical device and the like of the present disclosure including the above-described preferred configurations and modes, a mode may be adopted in which:

[0115] When the first A deflection element, the first B deflection element and the first C deflection element include volume holographic diffraction gratings, and

[0116] With respect to light emitted from the image forming device, the average diffraction efficiency of the first A deflecting member is η 1-A The average diffraction efficiency of the first B deflection element is η 1-B And the average diffraction efficiency of the first C deflection element is η 1-C hour,

[0117] Satisfy η 1-B / η 1-A <1, and

[0118] η 1-C / η 1-A <1

[0119] Furthermore, when the second A deflection element, the second B deflection element and the second C deflection element include volume holographic diffraction gratings, and

[0120] With respect to light emitted from the image forming device, the average diffraction efficiency of the second A deflecting member is η 2-A The average diffraction efficiency of the second B deflection element is η 2-B And the average diffraction efficiency of the second C deflection element is η 2-C hour,

[0121] Satisfy η 2-B / η 2-A <1, and

[0122] η 2-C / η 2-A <1

[0123] Preferably satisfying η 1-B ≤0.2, η 2-B ≤0.2, η 1-C ≤0.2 and η 2-C ≤0.2. Here, when the light intensity of light incident on the volume holographic diffraction grating is I0 and the light intensity of +1-order diffraction light diffracted by the volume holographic diffraction grating is I1, the diffraction efficiency η is represented by I1 / I0. For example, the diffraction efficiency can be controlled by the thickness of the volume holographic diffraction grating. That is, if the thickness of the volume holographic diffraction grating decreases, the value of the diffraction efficiency η becomes lower. In addition, as the refractive index modulation degree Δn in the volume holographic diffraction grating increases, the value of the diffraction efficiency η decreases. For example, when the diffraction efficiency η = 0.2 and the light (light amount = 1.0) incident on the volume hologram diffraction grating is emitted from the volume hologram diffraction grating, and when the light amount emitted from the area of ​​the volume hologram diffraction grating closest to the light incident part of the volume hologram diffraction grating is LI1, the light amount emitted from the area second closest to the volume hologram diffraction grating is LI2, the light amount emitted from the area third closest to the volume hologram diffraction grating is LI3 and the light amount emitted from the area fourth closest to the volume hologram diffraction grating is LI4,

[0124] LI1=1.0×0.2=0.2,

[0125] LI2=(1.0-0.2)×0.2=0.16,

[0126] LI3 = (1.0 - 0.2 - 0.16) × 0.2 = 0.128, and

[0127] LI4=(1.0-0.2-0.16-0.128)×0.2=0.102 holds true.

[0128] In the following description, in order to simplify the explanation, the first A deflection component and the second A deflection component may be collectively referred to as "the first A deflection component, etc.", the first B deflection component and the second B deflection component may be collectively referred to as "the first B deflection component, etc.", and the first C deflection component and the second C deflection component may be collectively referred to as "the first C deflection component, etc.".

[0129] In the optical device of the present disclosure including the above-mentioned preferred mode, a mode may be adopted in which the light beam emitted from the center point of the image forming area of ​​the image forming device is incident on the first A deflection member and the second A deflection member vertically or at a certain angle that is not vertical. That is, in the latter case,

[0130] The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin,

[0131] In the XYZ Cartesian coordinate system through the origin,

[0132] When the axis including the bisector toward the first direction is the +X axis (the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction),

[0133] The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and

[0134] When the axis orthogonal to the X-axis and the Z-axis is the Y-axis,

[0135] It is desirable that when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the first light guide plate (XZ plane), the angle formed by the orthogonally projected image and the X-axis is less than 90 degrees, and more preferably, it is equal to or greater than 70 degrees and less than 90 degrees. In addition, it is desirable that when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the YZ plane, the angle formed by the orthogonally projected image and the Y-axis is greater than or equal to -20 degrees and less than or equal to 20 degrees.

[0136] Furthermore, a mode may be adopted in which all light deflected by the first A deflection element is incident on the first B deflection element.

[0137] All the light deflected by the first B deflection element is incident on the first C deflection element,

[0138] All the light deflected by the second A deflection element is incident on the second B deflection element, and

[0139] All light deflected by the second B deflecting member is incident on the second C deflecting member. However, in reality, part of the light deflected by the first and second A deflecting members and part of the light deflected by the first and second B deflecting members may be lost through the light guide plate.

[0140] In addition, in the optical device of the present disclosure including the above-mentioned preferred mode, a mode can be adopted in which the refractive index of the material constituting the first light guide plate and the second light guide plate is 1.5 or greater, preferably 1.6 or greater, and the refractive index of the material constituting the volume holographic diffraction grating is 1.5 or greater, preferably 1.6 or greater.

[0141] In the optical device of the present disclosure including the above-mentioned preferred mode, etc., the optical device is a semi-transmissive type (perspective type). Specifically, at least a portion of the optical device opposite to the eyeball (pupil) of the observer is semi-transmissive (transparent), and the outside scene can be seen through this portion of the optical device (specifically, at least the first C deflection component and the second C deflection component). Here, the term "semi-transmissive" does not mean that 1 / 2 (50%) of the incident light is transmitted or reflected, but is used in the sense that a portion of the incident light is transmitted and the rest is reflected.

[0142] A monochrome (e.g., green) image can be displayed by the image display device or display device of the present disclosure. On the other hand, a configuration can be adopted in which, in the case of displaying a color image, in order to correspond to the diffraction of P-type light having wavelength bands (or wavelengths) of different P types (e.g., P=3, three types of red, green, and blue), a first A deflection component, etc., a first B deflection component, etc., and a first C deflection component, etc. are formed by stacking a P-layer diffraction grating layer including a volume holographic diffraction grating. Interference fringes corresponding to one type of wavelength band (or wavelength) are formed on each diffraction grating layer. Alternatively, a configuration can be adopted in which, in order to correspond to the diffraction of P-type light having different P-type wavelength bands (or wavelengths), P-type interference fringes are formed on a first A deflection component, etc., a first B deflection component, etc., and a first C deflection component, etc. including a diffraction grating layer. Alternatively, for example, a structure may be adopted in which the first A deflection component etc., the first B deflection component etc. and the first C deflection component etc. including a diffraction grating layer including a volume holographic diffraction grating that diffracts and reflects light having a red wavelength band (or wavelength) are arranged on the first light guide plate and the second light guide plate as the first, the first A deflection component etc., the first B deflection component etc. and the first C deflection component etc. including a diffraction grating layer including a volume holographic diffraction grating that diffracts light having a green wavelength band (or wavelength) are arranged on the first light guide plate and the second light guide plate as the second, the first A deflection component etc., the first B deflection component etc. and the first C deflection component etc. including a diffraction grating layer including a volume holographic diffraction grating that diffracts light having a blue wavelength band (or wavelength) are arranged on the first light guide plate and the second light guide plate as the third, and these six light guide plates are stacked with gaps therebetween. Alternatively, for example, the first A deflection member, etc., the first B deflection member, etc., and the first C deflection member, etc. that diffract light having a red or blue wavelength band, and the first A deflection member, etc., the first B deflection member, etc., and the first C deflection member, etc. that diffract light having a green wavelength band may be stacked on one surface of the first light guide plate, and the first A deflection member, etc., the first B deflection member, etc., and the first C deflection member, etc. that diffract light having a blue or red wavelength band may be arranged on the other surface of the first light guide plate. Similarly, the second A deflection member, etc., the second B deflection member, etc., and the second C deflection member, etc. that diffract light having a red or blue wavelength band, and the second A deflection member, etc., the second B deflection member, etc., and the second C deflection member, etc. that diffract light having a green wavelength band may be stacked on one surface of the second light guide plate, and the second A deflection member, etc., the second B deflection member, etc., and the second C deflection member, etc. that diffract light having a blue or red wavelength band may be arranged on the other surface of the second light guide plate.Then, by using these configurations, when light having each wavelength band (or wavelength) is diffracted by the first A deflection member, the first B deflection member, the first C deflection member, etc., the diffraction efficiency can be improved, the diffraction acceptance angle can be increased, and the diffraction angle can be optimized. It is preferable to arrange the protective member so that the volume holographic diffraction grating is not in direct contact with the atmosphere.

[0143] As a material constituting the volume holographic diffraction grating, a photopolymer material can be cited. The constituent materials and basic structure of the volume holographic diffraction grating in the optical device of the present disclosure, etc. only need to be the same as the constituent materials and structure of a conventional volume holographic diffraction grating. Interference fringes are formed on the volume holographic diffraction grating from its interior to the surface, and the method of forming such interference fringes itself only needs to be the same as the conventional formation method. Specifically, for example, it is only necessary to irradiate the material constituting the volume holographic diffraction grating (for example, a photopolymer material) with object light from a first predetermined direction on one side, and at the same time irradiate the material constituting the volume holographic diffraction grating with reference light from a second predetermined direction on the other side, and record the interference fringes formed by the object light and the reference light inside the material constituting the volume holographic diffraction grating. By appropriately selecting the first predetermined direction, the second predetermined direction and the wavelength of the object light and the reference light, the desired pitch of the interference fringes on the surface of the volume holographic diffraction grating and the desired inclination (oblique angle) of the interference fringes can be obtained. The inclination of the interference fringes means the angle formed by the surface of the volume holographic diffraction grating and the interference fringes. In the case where it is composed of a stacked structure of a diffraction grating layer of a P layer including a volume holographic diffraction grating, it is only necessary to stack such diffraction grating layers so that the diffraction grating layer of the P layer is prepared separately and then the diffraction grating layer of the P layer is stacked (bonded) by using, for example, an ultraviolet light-curing adhesive. In addition, after one layer of the diffraction grating layer is prepared by using a photopolymer material having adhesiveness, the photopolymer material having adhesiveness can be sequentially bonded thereon to prepare a diffraction grating layer, thereby preparing a diffraction grating layer of the P layer.

[0144] The inclination angle (oblique angle) of the interference fringes can be constant in the volume holographic diffraction grating, or can be changed according to the viewing angle value of the image incident on the volume holographic diffraction grating. In the case where the inclination angle of the interference fringes changes according to the viewing angle value of the incident image, it can be changed continuously or stepwise. In addition, by changing the interference ratio between the object light and the reference light, the diffraction efficiency of the interference fringes can be changed continuously or stepwise.

[0145] As a material constituting the volume holographic diffraction grating (a photopolymer material constituting a photosensitive material precursor layer before irradiation with object light and reference light), any photopolymer material can be used as long as it includes at least a photopolymerizable compound, a binder resin and a photopolymerization initiator. As a photopolymerizable compound, for example, a known photopolymerizable compound such as an acrylic monomer, a methacrylic monomer, a styrene monomer, a butadiene monomer, a vinyl monomer and an epoxy resin monomer can be used. These can be copolymers, monofunctional groups or multifunctional groups. In addition, these monomers can be used alone, or multiple of them can be used. Any known binder resin can be used, specifically, cellulose acetate resin, acrylic resin, acrylate resin, methacrylic resin, epoxy resin, polyurethane resin, polypropylene resin, polyvinyl ether resin, polycarbonate resin, polyamide resin, polyvinyl acetate, vinyl chloride resin, urea resin, styrene resin, butadiene resin, natural rubber resin, polyvinyl carbazole, polyethylene glycol and phenolic resin and their copolymers and gelatin, etc. can be cited. The binder resin can also be used alone, or multiple of them can be used. As a photopolymerization initiator, any known photopolymerization initiator can be used. The photopolymerization initiator can be used alone or multiple of them can be used, or it can be used in combination with multiple photosensitive dyes, or a single photosensitive dye can be used. Plasticizers, chain transfer agents and other additives can be appropriately added to the photosensitive material precursor layer. Any material as long as it is transparent can be used as a material for constituting a protective layer for protecting the volume holographic diffraction grating, and even if it is formed by coating, a pre-filmed material can be stacked on the photosensitive material precursor layer. As materials constituting the protective layer, for example, polyvinyl alcohol (PVA) resin, acrylic resin, polyurethane resin, polyethylene terephthalate (PET) resin, triacetyl cellulose (TAC) resin, polymethyl methacrylate (PMMA) resin, polypropylene resin, polycarbonate resin and polyvinyl chloride resin can be cited.

[0146] In the image display device of the present disclosure or the image display device in the display device including the above-mentioned various preferred modes, a mode in which the image forming device has a plurality of pixels arranged in a two-dimensional matrix can be adopted. Note that for convenience, the configuration of such an image forming device will be referred to as a "first configuration image forming device".

[0147] As an image forming device of the first configuration, for example, an image forming device including a reflective spatial light modulation device and a light source, an image forming device including a transmissive spatial light modulation device and a light source, and an image forming device including a light emitting element such as an organic electroluminescent (EL) element, an inorganic EL element, a light emitting diode (LED), and a semiconductor laser element can be cited, and, among them, an image forming device including a reflective spatial light modulation device and a light source or an image forming device including an organic EL element is preferred. As a spatial light modulation device, a transmissive or reflective liquid crystal display device of a light valve such as liquid crystal on silicon (LCOS), and a digital micromirror device (DMD) can be cited, and, as a light source, a light emitting element can be cited. In addition, a configuration can be adopted in which the reflective spatial light modulation device includes a liquid crystal display device and a polarized beam splitter, which reflects a portion of the light from the light source and guides the light to the liquid crystal display device and passes a portion of the light reflected by the liquid crystal display device and guides the light to the optical system. As the light emitting element constituting the light source, a red light emitting element, a green light emitting element, a blue light emitting element and a white light emitting element can be cited, or the red light, green light and blue light emitted from the red light emitting element, the green light emitting element and the blue light emitting element can be mixed by a light pipe and subjected to brightness uniformization to obtain white light. As the light emitting element, for example, a semiconductor laser element, a solid-state laser and an LED can be cited. The number of pixels only needs to be determined based on the specifications required for the image display device, and as a specific value of the number of pixels, 320×240, 432×240, 640×480, 1024×768 or 1920×1080 can be cited.

[0148] Alternatively, in the image display device of the present disclosure or the image display device including the above-mentioned preferred mode, a mode in which the image forming device includes a light source and a scanning means for scanning with parallel light emitted from the light source can be adopted. Note that for convenience, the configuration of such an image forming device will be referred to as "the image forming device of the second configuration".

[0149] As the light source in the image forming device of the second configuration, a light emitting element can be cited, specifically, a red light emitting element, a green light emitting element, a blue light emitting element and a white light emitting element can be cited, or the red light, green light and blue light emitted from the red light emitting element, the green light emitting element and the blue light emitting element can be mixed by a light pipe and subjected to brightness uniformization to obtain white light. As the light emitting element, for example, a semiconductor laser element, a solid-state laser and an LED can be cited. The number of pixels (virtual pixels) in the image forming device of the second configuration also only needs to be determined based on the specifications required by the image display device, and as a specific value of the number of pixels (virtual pixels), 320×240, 432×240, 640×480, 1024×768 or 1920×1080 can be cited. In addition, in the case of displaying a color image and forming a light source by a red light emitting element, a green light emitting element and a blue light emitting element, it is preferred to perform color synthesis by using, for example, a cross prism. As the scanning means, for example, a microelectromechanical system (MEMS) and a galvano mirror having a micromirror rotatable in two-dimensional directions that performs horizontal and vertical scanning using light emitted from a light source can be cited.

[0150] In the image forming device of the first configuration or the image forming device of the second configuration, a plurality of parallel lights are incident on a light guide plate in an optical system (the optical system is an optical system that causes the light emitted from the image forming device to become parallel lights, and can be referred to as a "parallel light emission optical system", specifically, for example, a collimating optical system or a relay optical system), and, specifically, this requirement of becoming parallel lights is based on the fact that the light wave plane information when these lights are incident on the light guide plate needs to be stored even after being emitted from the light guide plate through the first A deflection component, the first B deflection component, the first C deflection component, etc. Note that in order to generate a plurality of parallel lights, specifically, for example, it is only necessary to position the light emitting unit of the image forming device at the focal length positioning (position) in the parallel light emission optical system. The parallel light emission optical system has a function of converting the position information of a pixel into angle information in the optical system of an optical device. As a parallel light emission optical system, an optical system having a positive optical focal length as a whole can be cited in which a convex lens, a concave lens, a free bending prism, and a holographic lens are used alone or in combination.

[0151] In order to make the light emitted from the parallel light emitting optical system enter the first A deflection component and the second A deflection component, it is only necessary to arrange appropriate light guiding means between the parallel light emitting optical system and the first A deflection component and the second A deflection component. As the light guiding means, a reflector can be cited. In addition, the light emitted from the parallel light emitting optical system can be directly converged on the first A deflection component and the second A deflection component.

[0152] The light guide plate has two parallel surfaces (a first surface and a second surface). When the surface of the light guide plate on which light is incident is the light guide plate incident surface and the surface of the light guide plate from which light is emitted is the light guide plate emission surface, the first surface may form the light guide plate incident surface and the light guide plate emission surface, or the first surface may form the light guide plate incident surface and the second surface may form the light guide plate emission surface.

[0153] As a material constituting the light guide plate, glass or plastic materials containing optical glass such as quartz glass or BK7 (for example, PMMA, polycarbonate resin, acrylic resin, amorphous polypropylene resin, and styrene resin containing AS resin) can be cited. The shape of the light guide plate is not limited to a flat plate, and may have a curved shape. As a material having a refractive index of 1.5 or more, BK7, polycarbonate resin, amorphous polypropylene resin, and styrene resin containing AS resin can be cited, and, as a material having a refractive index of 1.6 or more, acrylic resin can be cited.

[0154] The image display device may include a light control device. That is, the optical device may overlap at least a portion of the light control device. More specifically, it is preferred that at least a first C deflection component and a second C deflection component of the optical device overlap the light control device. The light control device will be described in detail later.

[0155] In the display device of the present disclosure, a configuration can be adopted in which the frame includes a front portion arranged in front of the observer and two temple portions pivotally attached to both ends of the front portion by a hinge. Note that the temple tips are attached to the tip portions of each temple portion. The image display device is attached to the frame, specifically, for example, it is only necessary to attach the image forming device to the upper portion of the front portion. In addition, a configuration can be adopted in which the front portion and the two temple portions are integrated. That is, when the entire display device of the present disclosure is viewed, the frame has substantially the same structure as ordinary glasses. The material constituting the frame including the pad portion can be formed of the same material (such as metal, alloy, plastic or a combination thereof) as the material forming ordinary glasses. In addition, a configuration can be adopted in which the nose pad is attached to the front portion. That is, when the entire display device of the present disclosure is viewed, the assembly of the frame (including the edge) and the nose pad has substantially the same structure as ordinary glasses. The nose pad may also have a known configuration and structure.

[0156] In addition, in the display device of the present disclosure, from the perspective of design or easy installation, it is desirable to adopt a mode in which the wiring (signal line or power line, etc.) from one or two image forming devices extends from the tip part of the temple tip via the temple part and the inside of the temple tip to the outside and is connected to the control device (control circuit or control means). In addition, a mode in which each image forming device includes an earphone part and the wiring for the earphone part from each image forming device extends from the tip part of the temple tip via the inside of the temple tip to the earphone part. As the earphone part, for example, an inner ear type earphone part and an ear canal type earphone part can be cited. More specifically, it is preferred to adopt a mode in which the wiring for the earphone part extends from the tip part of the temple tip to the earphone part to surround the back of the auricle (ear auricle). In addition, a mode in which an imaging device is attached to the center part of the front can be adopted. Specifically, the imaging device includes, for example, a solid-state image sensor including a CCD or CMOS sensor and a lens. The wiring from the imaging device only needs to be connected to an image display device (or image forming device) via, for example, the front and is further included in the wiring extending from the image display device (or image forming device).

[0157] Using the display device of the present disclosure, for example, a head-mounted display (HMD) can be formed. In this way, the weight and size of the display device can be reduced, the discomfort when attaching the display device can be significantly reduced, and the manufacturing cost can also be reduced. Alternatively, the image display device of the present disclosure can be applied to a head-up display (HUD) set in a vehicle or an aircraft cockpit, etc. Specifically, the HUD can be formed so that a virtual image forming area that forms a virtual image based on light emitted from an image forming device is arranged on a windshield of a vehicle or an aircraft cockpit, etc., or the HUD can be formed so that a synthesizer having a virtual image forming area that forms a virtual image based on light emitted from an image forming device is arranged on a windshield of a vehicle or an aircraft cockpit, etc.

[0158] [First embodiment]

[0159] The first embodiment relates to an optical device of the present disclosure, an image display device of the present disclosure, and a display device of the present disclosure. Figure 1A A schematic diagram of a first light guide plate and a first deflection unit constituting an optical device of a first embodiment is shown in FIG. Figure 1B A schematic diagram of a second light guide plate and a second deflection unit is shown. Figure 2A 2 is a schematic diagram showing the arrangement of the first A deflection member, the first B deflection member and the first C deflection member constituting the optical device of the first embodiment. Figure 2B A conceptual diagram showing the wave vectors of the first A deflection unit, the first B deflection unit, and the first C deflection unit. Figure 3A and Figure 3BA schematic cross-sectional view of an optical device according to a first embodiment is shown in FIG. Figure 3C A schematic diagram of the optical device as seen from the side is shown in Figure 4 A schematic diagram of the optical device of the first embodiment as viewed from above is shown in Figure 5 A schematic diagram of a display device of the first embodiment as viewed from the front is shown in FIG. Fig. 6A , Figure 6B and Figure 6C A conceptual diagram of an image forming device in a display device of the first embodiment is shown in FIG. Figure 1A , Figure 1B , Fig. 8A , Figure 8B , Fig. 10A , Fig. 10B , Fig. 12A and Fig. 12B is a conceptual diagram of an optical device constituting an image display device for the right eye viewing from the front, wherein the nose of the observer is located on the right-hand side of the diagram and the ear of the observer is located on the left-hand side of the diagram.

[0160] The optical device 10 of the first embodiment is an optical device in which light emitted from an image forming device 60 is incident, guided, and emitted, and includes a first light guide plate 21 and a second light guide plate 22, and a first deflection unit 30 provided on the first light guide plate 21 and a second deflection unit 40 provided on the second light guide plate 22.

[0161] The first deflection unit 30 includes a first A deflection member 31, a first B deflection member 32, and a first C deflection member 33, and,

[0162] The second deflection unit 40 includes a second A deflection member 41 , a second B deflection member 42 , and a second C deflection member 43 .

[0163] Then, a portion of the light emitted from the image forming device 60 is incident on the first A deflection component 31, the light incident on the first A deflection component 31 is deflected by the first A deflection component 31, is totally reflected in the first light guide plate 21 and is incident on the first B deflection component 32, is deflected by the first B deflection component 32, is totally reflected in the first light guide plate 21 and is incident on the first C deflection component 33, is deflected by the first C deflection component 33, and is emitted toward the pupil 90 of the observer.

[0164] In addition, at least a remaining portion of the light emitted from the image forming device 60 is incident on the second A deflection component 41, the light incident on the second A deflection component 41 is deflected by the second A deflection component 41, is totally reflected within the second light guide plate 22 and is incident on the second B deflection component 42, is deflected by the second B deflection component 42, is totally reflected within the second light guide plate 22 and is incident on the second C deflection component 43, is deflected by the second C deflection component 43, and is emitted toward the pupil 90 of the observer.

[0165] Then, the propagation direction of the light deflected by the first B deflection member 32 in the first light guide plate 21 is the first direction when orthogonally projected onto the first light guide plate 21, and the propagation direction of the light deflected by the second B deflection member 42 in the second light guide plate 22 is the second direction when orthogonally projected onto the first light guide plate 21, and the first direction is opposite to the second direction. Note that the first direction and the second direction are not parallel to each other. However, it is not limited to this state, and in some cases, the first direction and the second direction may be on the same straight line.

[0166] Furthermore, the image display device 11 of the first embodiment includes:

[0167] an image forming device 60; and

[0168] an optical device that incident, guides, and emits light emitted from the image forming device 60,

[0169] The optical device includes the optical device 10 of the first embodiment.

[0170] Furthermore, the display device of the first embodiment includes:

[0171] a frame 50 attached to the viewer's head; and

[0172] The image display device 11 is attached to the frame 50,

[0173] Among them, the image display device 11 includes an image forming device 60 and an optical device that incidents, guides, and emits light emitted from the image forming device 60, and

[0174] The optical device includes the optical device 10 of the first embodiment.

[0175] Then, in the optical device of the first embodiment, the first light guide plate 21 and the second light guide plate 22 are juxtaposed. That is, the first light guide plate 21 and the second light guide plate 22 are arranged in parallel and separated with, for example, an air layer interposed therebetween.

[0176] Specifically, the display device of the first embodiment is a binocular type having two image display devices 11, but a monocular type having one may be used. The optical device 10 is a perspective type (semi-transmissive type). In addition, the image forming device 60 displays a monochrome image, but is not limited thereto. The image display device for the right eye will be described below based on the coordinate axis of the right-hand system, but for the image display device for the left eye, it only needs to be read as the coordinate axis of the left-hand system.

[0177] In the optical device 10 of the first embodiment,

[0178] The point on the first light guide plate 21 where the light beam emitted from the center point of the image forming area of ​​the image forming device 60 collides with the first light guide plate 21 is the origin O.

[0179] In the XYZ Cartesian coordinate system passing through the origin O,

[0180] When the axis including the bisector toward the first direction (the bisector is the bisector of the acute angle within the angle between the straight line passing through the origin O and parallel to the first direction and the straight line passing through the origin O and parallel to the second direction) is the +X axis,

[0181] The axis passing through the origin O and perpendicular to the first light guide plate 21 is the Z axis, and

[0182] When the axis orthogonal to the X-axis and the Z-axis is the Y-axis,

[0183] The first deflection unit 30 and the second deflection unit 40 are arranged at positions symmetrical with respect to the YZ plane. As will be described later, a mode may be adopted in which a light beam emitted from the center point of the image forming area of ​​the image forming device 60 is vertically incident on the first A deflection member 31 and the second A deflection member 41, or, as will be described later, a mode may be adopted in which it is incident at a certain angle. In addition, it is assumed that the light beam emitted from the center point of the image forming area of ​​the image forming device 60 is incident on the center of the pupil of the observer.

[0184] The first direction, which is the direction in which the propagation direction of the light deflected by the first B deflection unit 32 in the first light guide plate 21 is orthogonally projected onto the first light guide plate 21, extends in the +X axis direction. However, it does not extend parallel to the +X axis. In addition, the second direction, which is the direction in which the propagation direction of the light deflected by the second B deflection unit 42 in the second light guide plate 22 is orthogonally projected onto the first light guide plate 21, extends in the -X axis direction. However, it does not extend parallel to the -X axis. When a plane including the observer's line of sight when viewing an object located in the horizontal direction (e.g., a horizontal object, an object at infinity, or the horizon or the sea horizon) ("observer's horizontal line of sight") and including the observer's two horizontally positioned pupils is assumed to be a "horizontal plane", and a plane perpendicular to the horizontal plane is assumed to be a "vertical plane", in the first embodiment, the +X axis and the -X axis are located in the horizontal plane.

[0185] Here, a (x0, y0, z0) Cartesian coordinate system centered at the origin O is assumed. The x0 axis is an axis parallel to the pupil axis passing through the center of the observer's pupil 90. The z0 axis is in the XZ plane, and the y0 axis is orthogonal to the x0 and y0 axes. The "+" direction of the x0 axis is the direction away from the observer. The "+" direction of the z0 axis is the direction from the observer's ear to the nose. Here, the "pupil axis" is defined as a line passing through the center of the entrance pupil of the eye and perpendicular to the corneal surface.

[0186] As mentioned above, Fig.22A As shown, the first light guide plate 21 and the second light guide plate 22 may be arranged so that the X axis coincides with the x0 axis and the Z axis coincides with the z0 axis. Fig.22A , Fig. 22B and Fig. 22C , a light beam emitted from the center point of the image forming area of ​​the image forming device 60 is shown by a dotted line, a pupil axis is shown by an alternating long and short dashed line, and these diagrams are for the image display device for the right eye.

[0187] Or, if Fig. 22B and Fig. 22C As shown, the end A of the first light guide plate 21 and the second light guide plate 22 located on the observer's nose side can be arranged to be more forward than the end B located on the observer's ear side. In this case, the angle θ0 formed by the X-axis and the z0-axis is a value exceeding 0 degrees (θ0>0). Specifically, the value of θ0 preferably satisfies 0 (degrees) < θ0 ≤ 20 (degrees). In addition, when the light beam emitted from the center point of the image forming area of ​​the image forming device 60 is incident on the origin O, the angle formed by the X-axis and the Y-axis is (θ X ,θ Y ), that is, when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin O is orthogonally projected onto the first light guide plate 21 (XZ plane), the angle formed by the orthogonally projected image and the X axis is θX And when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin O is orthogonally projected onto the YZ plane, the angle formed by the orthogonally projected image and the Y axis is θ Y When the light beam emitted from the center point of the image forming area of ​​the image forming device enters the light guide plate from the observer side (see Fig. 22B ), preferably satisfying:

[0188] 70 degrees≤θ X <90 degrees, and

[0189] -20 degrees≤θ Y ≤20 degrees.

[0190] Furthermore, in the case where a light beam emitted from the center point of the image forming area of ​​the image forming device is incident on the light guide plate from the side opposite to the observer (see Fig. 22C ), preferably satisfying:

[0191] 70 degrees≤θ X <90 degrees, and

[0192] -20 degrees≤θ Y ≤20 degrees.

[0193] θ0 and θ X The relationship between is preferably θ0≥(90-θ X That is, it is desired that the angle (θ) formed by the orthogonal projection image and the X-axis when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin O is orthogonally projected onto the first light guide plate 21 (XZ plane) X ) is less than 90 degrees, and more preferably it is equal to or greater than 70 degrees and less than 90 degrees. In addition, it is desirable that the angle (θ) formed by the orthogonal projection image and the Y axis when the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin O is orthogonally projected onto the YZ plane is Y ) is greater than or equal to -20 degrees and less than or equal to 20 degrees.

[0194] In the example shown, the first A deflection member 31 and the second A deflection member 41 constituting the first deflection unit 30 and the second deflection unit 40 are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape. Similarly, the first B deflection member 32 and the second B deflection member 42 are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape, and the first C deflection member 33 and the second C deflection member 43 are arranged at positions symmetrical about the YZ plane, symmetrically and have the same shape. Specifically, for example, it is possible to adopt a configuration in which the first deflection unit 30 displays an image having a horizontal viewing angle of 20 degrees to a horizontal viewing angle of 0 degrees and a vertical viewing angle of ±20 degrees, and the second deflection unit 40 displays an image having a horizontal viewing angle of 0 degrees to a horizontal viewing angle of -20 degrees and a vertical viewing angle of ±20 degrees. That is, in the optical device of the first embodiment, specifically, half of the light emitted from the image forming device 60 is incident on the first A deflection member 31, and the other half of the light emitted from the image forming device 60 is incident on the second A deflection member 41. An image having a horizontal viewing angle in the positive direction corresponds to an image occupying the nose side of the observer, and an image having a horizontal viewing angle in the negative direction is an image occupying the ear side of the observer.

[0195] However, this is not limited to the above, and the first A deflection member 31 and the second A deflection member 41 constituting the first deflection unit 30 and the second deflection unit 40 may be arranged at positions symmetrical about the YZ plane but have different shapes. Similarly, the first B deflection member 32 and the second B deflection member 42 may be arranged at positions symmetrical about the YZ plane and have different shapes, and, similarly, the first C deflection member 33 and the second C deflection member 43 may be arranged at positions symmetrical about the YZ plane and have different shapes. Specifically, for example, it is possible to adopt a configuration in which the first deflection unit 30 displays an image having a horizontal viewing angle of 16 degrees to a horizontal viewing angle of 0 degrees and a vertical viewing angle of ±20 degrees and the second deflection unit 40 displays an image having a horizontal viewing angle of 0 degrees to a horizontal viewing angle of -23 degrees and a vertical viewing angle of ±20 degrees.

[0196] In the optical device 10 of the first embodiment, the first A deflecting member 31, the first B deflecting member 32, and the first C deflecting member 33, and the second A deflecting member 41, the second B deflecting member 42, and the second C deflecting member 43 each include a volume holographic diffraction grating. Figure 3AAs shown, the first light guide plate 21 has two parallel surfaces (a first surface 21A and a second surface 21B), and, for example, the first surface 21A forms a light guide plate incident surface of the first light guide plate 21, and the second surface 21B forms a light guide plate emission surface of the first light guide plate 21. In addition, the second light guide plate 22 has two parallel surfaces (a first surface 22A and a second surface 22B), and, for example, the first surface 22A forms a light guide plate incident surface of the second light guide plate 22, and the second surface 22B forms a light guide plate emission surface of the second light guide plate 22. Alternatively, as Figure 3B As shown, the first light guide plate 21 has two parallel surfaces (a first surface 21A and a second surface 21B), and, for example, the first surface 21A forms a light guide plate incident surface of the first light guide plate 21, and the second surface 21B forms a light guide plate emission surface of the first light guide plate 21. In addition, the second light guide plate 22 has two parallel surfaces (a first surface 22A and a second surface 22B), and, for example, the first surface 22A forms a light guide plate incident surface of the second light guide plate 22, and the second surface 22B forms a light guide plate emission surface of the second light guide plate 22.

[0197] Then, the first A deflection component 31, the first B deflection component 32, the first C deflection component 33, the second A deflection component 41, the second B deflection component 42 and the second C deflection component 43, which respectively include reflective volume holographic diffraction gratings, are arranged (specifically, joined) on the second surfaces 21B and 22B or the first surfaces 21A and 22A of the first light guide plate 21 and the second light guide plate 22. The first A deflection component 31, the first B deflection component 32, the first C deflection component 33, the second A deflection component 41, the second B deflection component 42 and the second C deflection component 43 include a diffraction grating layer. Interference fringes corresponding to one type of wavelength band (or wavelength) are formed in each deflection component formed of a photopolymer material and manufactured by a conventional method. The pitch of the interference fringes formed on the deflection component (diffractive optical element) is constant, and the interference fringes are linear. The inclination angle (tilt angle) of the interference fringes can be constant in the volume holographic diffraction grating, or can change according to the viewing angle value of the image incident on the volume holographic diffraction grating. In the case where the inclination angle of the interference fringes changes according to the viewing angle value of the incident image, it can change continuously or step by step.

[0198] In order to make the light incident on the first A deflection member 31 and the second A deflection member 41 totally reflected in the light guide plates 21 and 22, the angle (incident angle) of the light propagating in the light guide plates 21 and 22 and colliding with the first surface 21A, 22A or the second surface 21B, 22B of the light guide plates 21 and 22 needs to be greater than the total reflection angle. Therefore, for example, the incident angle of the light on the first A deflection member 31 must satisfy the following conditions:

[0199] k v ·sin(θ in )+m·k v 1-A =k v ·sin(θ diff )

[0200] In addition, θ diff It needs to be a value greater than the total reflection angle. Here,

[0201] k v ...the wave vector of the incident light,

[0202] θ in ... the angle of incidence,

[0203] θ diff ...the diffraction angle, and

[0204] m... series

[0205] The diffraction angle with respect to the image viewing angle is defined by an equation satisfying the Bragg condition described later, and is determined by the wavelength λ and the pitch d of the grating surface. Fig.21 The graph of shows the relationship between the incident angle of light on the first A deflection member 31 or the second A deflection member 41 and the diffraction angle of the first A deflection member 31 or the second A deflection member 41, where the pitch d is a parameter. Fig.21 In the figure, “A” represents data with a pitch of d=300 nm, “B” represents data with a pitch of d=320 nm, “C” represents data with a pitch of d=340 nm, “d” represents data with a pitch of d=360 nm, and “E” represents data with a pitch of d=380 nm.

[0206] Incidentally, the diffraction angle θ with respect to the viewing angle of the image diff In the case of a transmission type volume holographic diffraction grating, the value of m is preferably "-1" (-1 order), and the incident viewing angle corresponds to a diffraction angle of -90 degrees to the total reflection angle (see Fig.21 ). The first A deflection element 31 and the second A deflection element 41 share a horizontal viewing angle in the +X axis direction and the -X axis direction, respectively, but preferably the responsible horizontal viewing angles overlap. Fig.21The graph shows the relationship between the pitch d and the diffraction angle when the wavelength is 530nm in the first A deflection component 31 or the second A deflection component 41. In this case, it is preferable to select a pitch in which the incident horizontal viewing angles overlap, such as "D" and "E", where 0 degrees is the boundary. The larger the overlapping incident angle, the narrower the horizontal viewing angle that can reach the pupil. However, it is only necessary to set the width of the deflection component to be equal to the pitch of total reflection, and in this case, the width of the deflection component can be set in consideration of the wavelength dispersion of the light source. For example, when the thickness of the light guide plate is T and the pitch of total reflection of the light totally reflected inside the light guide plate is Pt ir When , the width of the deflection member (specifically, the width of the first A deflection member 31 along the +X axis direction and the width of the second A deflection member 41 along the -X axis direction) only needs to be set to satisfy the following equation:

[0207] Width of deflection element = Pt ir =2·T·tan(θ diff ).

[0208] For example, in the case where the wavelength half width of the light source including the LED is 30 nm, it is preferable to calculate the range of 500 nm to 560 nm and set the minimum width of the deflection member or set the diffraction angle θ diff The maximum angle of

[0209] Here, it is preferred that all the light deflected by the first A deflection element 31 is incident on the first B deflection element 32.

[0210] All the light deflected by the first B deflection element 32 is incident on the first C deflection element 33.

[0211] All the light deflected by the second A deflection element 41 is incident on the second B deflection element 42, and

[0212] All the light deflected by the second B deflecting member 42 is incident on the second C deflecting member 43. However, light loss on the light guide plates 21 and 22 is not included.

[0213] Light propagates in the light guide plates 21 and 22 by total reflection from the first A deflection member, etc. to the first B deflection member, etc., and therefore, the image incident on the light guide plates 21 and 22 is extended (enlarged) in the Y-axis direction. In addition, light propagates in the light guide plates 21 and 22 by total reflection from the first B deflection member, etc. to the first C deflection member, etc., and therefore, the image extended (enlarged) in the Y-axis direction is further extended in the +X-axis direction and the -X-axis direction. In this way, the image from the image forming device 60 is stretched (enlarged) in the vertical direction and the horizontal direction and reaches the pupil 90 of the observer. In addition, the parallel light from the image forming device 60 is diffracted (specifically, multiple diffracted and reflected) by the first A deflection member, etc. and the first B deflection member, etc., propagates in the light guide plates 21 and 22 by total reflection, and is emitted from the light guide plates 21 and 22 from the second surface 22 as parallel light as it is.

[0214] The surfaces of the first A deflection member, etc., the first B deflection member, etc., and the first C deflection member, etc. that are not opposite to the light guide plate 20 may be covered with a transparent resin plate or a transparent resin film to have a structure that prevents damage to the first A deflection member, etc., the first B deflection member, etc., and the first C deflection member, etc. In addition, a transparent protective film may be attached to the first surface 21 or the second surface 22 of the light guide plate 20 to protect the light guide plate 20.

[0215] In the example shown, the planar shape of the first A deflection member, etc. and the first C deflection member, etc. is a rectangle, and the planar shape of the first B deflection member, etc. is a trapezoid. However, the planar shapes of these members are not limited thereto. For example, the planar shape of the first A deflection member, etc. may be a circle, or the planar shape of the first B deflection member, etc. may be a rectangle. The planar shapes of the light guide plates 21 and 22 may also be shapes having cutout angles.

[0216] The wavelength of light (monochrome) emitted from the image forming device 60 is set to λ0=530nm. In addition, the material constituting the light guide plates 21 and 22 is glass with a thickness of 1.0mm (refractive index of 1.51), and the average refractive index of the photopolymer material constituting the first A deflection member, the first B deflection member, the first C deflection member, etc. is 1.51. Note that although the thickness of the light guide plates 21 and 22 does not substantially contribute to widening the viewing angle of the displayed image, by reducing the thickness of the light guide plates 21 and 22, the size of the first A deflection member, etc. can be reduced, and the parallel light emitting optical system constituting the image forming device 60 can be miniaturized, and by increasing the thickness of the light guide plates 21 and 22, the number of total reflections on the light guide plates 21 and 22 can be reduced and scattering on the reflection surface can be suppressed, and a high-quality image can be projected. Therefore, it is necessary to select the light guide plates 21 and 22 with the optimal thickness.

[0217] Hereinafter, the arrangement of the first A deflection unit 31, the first B deflection unit 32, and the first C deflection unit 33 constituting the first deflection unit 30 will be described, but the arrangement of the second A deflection unit 41, the second B deflection unit 42, and the second C deflection unit 43 constituting the second deflection unit 40 may be similar to that of the first deflection unit 30 except that the orientation is different. Furthermore, as described above, the image display device for the right eye will be described below based on the coordinate axes of the right-hand system.

[0218] Here, interference fringes with an inclination angle (oblique angle) Φ are formed on the volume holographic diffraction grating. The inclination angle Φ refers to the angle formed by the surface of the volume holographic diffraction grating and the interference fringes. The interference fringes are formed from the inside to the surface of the volume holographic diffraction grating. The interference fringes satisfy the Bragg condition. The Bragg condition in the reflective volume holographic diffraction grating refers to the condition that satisfies the following equation (A). In equation (A), m represents a positive integer, λ represents the wavelength, d represents the pitch of the grating surface (including the interval in the normal direction of the virtual plane of the interference fringes), and Θ is the complementary angle of the incident angle on the interference fringes. In addition, the relationship between Θ, the inclination angle Φ and the incident angle Ψ when light enters the volume holographic diffraction grating at an incident angle Ψ is as shown in equation (B).

[0219] m·λ=2·d·sin(Θ) (A)

[0220] Θ=90°-(Φ+Ψ) (B)

[0221] Fig. 8A and 8B : is a schematic diagram showing a first stage arrangement of the first A deflection member 31, the first B deflection member 32, and the first C deflection member 33 constituting the first deflection unit 30, and the second A deflection member 41, the second B deflection member 42, and the second C deflection member 43 constituting the second deflection unit 40. In addition, Fig.9A and Fig. 9B They are respectively a schematic diagram of the first stage arrangement of the first A deflection unit, the first B deflection unit and the first C deflection unit constituting the optical device of the first embodiment and a conceptual diagram of the wave vectors etc. of the first A deflection unit, the first B deflection unit and the first C deflection unit in the first stage arrangement.

[0222] In the first stage arrangement, when the wave vector of the first A deflection element 31 is k v 1-A ′,k v 1-A The X, Y and Z components of ′ are k X 1-A ′, k Y 1-A ′ and k Z 1-A', the wave vector of the second A deflection element 41 is k v 2-A ′ and k v 2-A The X, Y and Z components of ′ are k X 2-A ′, k Y 2-A ′ and k Z 2-A ′, k X 1-A ′=-k X 2-A ′=0,

[0223] k Y 1-A ′=k Y 2-A ′ = 0, and

[0224] k Z 1-A ′=k Z 2-A '

[0225] In addition, when the wave vector of the first C deflection element 33 is k v 1-C ′,k v 1-C The X, Y and Z components of ′ are k X 1-C ′, k Y 1-C ′ and k Z 1-C ', the wave vector of the second C deflection element 43 is k v 2-C ′ and k v 2-C The X, Y and Z components of ′ are k X 2-C ′, k Y 2-C ′ and k Z 2-C 'hour

[0226] k X 1-C ′=-k X 2-C ′=0,

[0227] k Y 1-C ′=k Y 2-C ′ = 0, and

[0228] k Z 1-C ′=kZ 2-C '

[0229] In addition, when the wave vector of the first B deflection element 32 is k v 1-B ′,k v 1-B The X, Y and Z components of ′ are k X 1-B ′,k Y 1-B ′ and k Z 1-B ', the wave vector of the second B deflection element 42 is k v 2-B ′ and k v 2-B The X, Y and Z components of ′ are k X 2-B ′,k Y 2-B ′ and k Z 2-B 'hour,

[0230] k X 1-B ′=-k X 2-B ′=0,

[0231] k Y 1-B ′=k Y 2-B ′ = 0, and

[0232] k Z 1-B ′=k Z 2-C '.here,

[0233] Satisfy k v 1-A ′+k v 1-B ′+k v 1-C ′ = 0, and

[0234] k v 2-A ′+k v 2-B ′+k v 2-C ′=0

[0235] exist Fig.16A The simulation results of this state are shown in FIG. Fig.16A , Fig. 16B and Fig.17FIG. 1 is a diagram showing a first deflection element 31, a first deflection element 32, and a first deflection element 33 constituting the first deflection unit 30. Fig. 20 Graph showing simulation results when the state shown is arranged, that is, the first A deflection member 31 and the second A deflection member 41 are arranged in a combined state and the first B deflection member 32 and the second B deflection member 42 are arranged in a combined state. Fig.16A , Fig. 16B , Fig.17 , Fig.19A and Fig.19B In , "A" represents the area of ​​the image obtained by the light of wavelength λ0 having peak intensity among the light emitted from the light source, "B" represents the area of ​​the image obtained by the wavelength (λ0-10nm) among the light emitted from the light source, and "C" represents the area of ​​the image obtained by the wavelength (λ0+10nm) among the light emitted from the light source. In addition, in Fig.16A , Fig. 16B , Fig.17 , Fig.19A and Fig.19B In the figure, the horizontal axis is the value of the field of view (FOV) in the Y-axis direction, and the vertical axis is the value of the FOV in the X-axis direction. Fig.18A and 18B In FIG. 1 , the horizontal axis represents the position of the first light guide plate 21 in the ±X axis directions, and the vertical axis represents the position of the first light guide plate 21 in the ±Y axis directions.

[0236] exist Fig. 10A and Fig. 10B , a schematic diagram of a second stage arrangement of the first A deflection component 31, the first B deflection component 32, and the first C deflection component 33 constituting the first deflection unit 30 and the second A deflection component 41, the second B deflection component 42, and the second C deflection component 43 constituting the second deflection unit 40 is shown. Fig.11A and Fig. 11B In the figure, there are shown a schematic diagram of the second stage arrangement of the first A deflection component, the first B deflection component and the first C deflection component constituting the optical device of the first embodiment, and a conceptual diagram of the wave vectors of the first A deflection component, the first B deflection component and the first C deflection component in the second stage arrangement.

[0237] In the second stage arrangement, the first deflection unit 30 is arranged in a state rotated, for example, by 7 degrees in the first rotation direction in the clockwise direction with the origin O as the center. In addition, the second deflection unit 40 is arranged in a state rotated, for example, by 7 degrees (for example, in the clockwise direction, -7 degrees) in the second rotation direction in the counterclockwise direction with the origin O as the center. Fig. 16B The simulation results of the image obtained by this rotation are shown in FIG. 1 and it can be seen that Fig.16AIn comparison, they move in the +X-axis direction and the Y-axis direction. Note that, instead of arranging the first deflection unit 30 in a state rotated, for example, by 7 degrees in the first rotation direction in the clockwise direction, the wave vectors of the first A deflection component 31, the first B deflection component 32, and the first C deflection component 33 constituting the first deflection unit 30 may be in a state rotated, for example, by 7 degrees in the first rotation direction in the clockwise direction. And, instead of arranging the second deflection unit 40 in a state rotated, for example, by 7 degrees in the second rotation direction in the counterclockwise direction (for example, in the clockwise direction, -7 degrees), the wave vectors of the second A deflection component 41, the second B deflection component 42, and the second C deflection component 43 constituting the second deflection unit 40 may be in a state rotated, for example, by 7 degrees in the second rotation direction in the counterclockwise direction (for example, in the clockwise direction, -7 degrees).

[0238] Note that in the second stage arrangement, when the wave vector of the first A deflection element 31 is k v 1-A ″,k v 1-A The X, Y and Z components of ″ are k X 1-A ″、k Y 1-A ″ and k Z 1-A ″, the wave vector of the second A deflection component 41 is k v 2-A ″ and k v 2-A The X, Y and Z components of ″ are k X 2-A ″、k Y 2-A ″ and k Z 2-A "hour,

[0239] k X 1-A +k X 2-A =0,

[0240] k Y 1-A ″=k Y 2-A ",as well as

[0241] k Z 1-A ″=k Z 2-A ″

[0242] In addition, when the wave vector of the first C deflection element 33 is k v 1-C ″,k v1-C The X, Y and Z components of ″ are k X 1-C ″、k Y 1-C ″ and k Z 1-C ″, the wave vector of the second C deflection element 43 is k v 2-C ″ and k v 2-C The X, Y and Z components of ″ are k X 2-C ″、k Y 2-C ″ and k Z 2-C "hour,

[0243] k X 1-C ″+k X 2-C "=0,

[0244] k Y 1-C ″=k Y 2-C ",as well as

[0245] k Z 1-C ″=k Z 2-C ″

[0246] In addition, when the wave vector of the first B deflection element 32 is k v 1-B ″,k v 1-B The X, Y, and Z components are k X 1-B ″、k Y 1-B ″ and k Z 1-B ″, the wave vector of the second B deflection element 42 is k v 2-B ″ and k v 2-B The X, Y and Z components of ″ are k X 2-B ″、k Y 2-B ″ and k Z 2-B "hour,

[0247] k X 1-B ″+k X 2-B "=0,

[0248] k Y 1-B ″=k Y 2-B ",as well as

[0249] k Z 1-B ″=k Z 2-C ".here,

[0250] Satisfy k v 1-A ″+k v 1-B ″+k v 1-C = 0 and

[0251] k v 2-A ″+k v 2-B ″+k v 2-C ″=0

[0252] That is, in the optical device of the first embodiment,

[0253] The first deflection unit 30 is arranged in a state of rotating in a first rotation direction in a counterclockwise direction or a clockwise direction with the Z axis as the center. In addition, the second deflection unit 40 is arranged in a state of rotating in a second rotation direction in a clockwise direction or a counterclockwise direction with the Z axis as the center. In addition, when the rotation angle in the first rotation direction is and the rotation angle in the second rotation direction is hour,

[0254] Hope to meet

[0255] And, I hope

[0256]

[0257] Specifically, in the example shown, the first deflection unit 30 rotates in a first rotation direction in a clockwise direction with the origin O as the center. The second deflection unit 40 is arranged in a state of 7 degrees (+7 degrees), and the second deflection unit 40 rotates in a second rotation direction in the counterclockwise direction with the origin O as the center. It is arranged at a temperature of -7 degrees.

[0258] By the way, if Fig. 8A The first deflection unit 30 shown is arranged in a state rotated, for example, by 7 degrees in a first rotation direction in the clockwise direction with the origin O as the center. Figure 8B The second deflection unit 40 shown is arranged in a state where it is rotated, for example, by 7 degrees in the second rotation direction in the counterclockwise direction (for example, -7 degrees in the clockwise direction) with the origin O as the center, and then Fig. 10A and Fig. 10B However, in these states, a "missing portion" appears in the image at and near the Y axis. Fig. 10A and Fig. 10B In FIG. 1 , the area where loss occurs in the image is shown by the area surrounded by the dotted line.

[0259] Therefore, in order to prevent such image loss, in each of the first B deflection unit 32 and the second B deflection unit 42, the first B deflection unit orthogonal projection image when the first B deflection unit 32 is orthogonally projected onto the first light guide plate 21 and the second B deflection unit orthogonal projection image when the second B deflection unit 42 is orthogonally projected onto the first light guide plate 21 partially overlap. In addition, the end of the first B deflection unit orthogonal projection image in the +X axis direction and the end of the second B deflection unit orthogonal projection image in the -X axis direction overlap. Fig. 12A and Fig. 12B A schematic diagram of such a second stage arrangement of the first deflection unit of the optical device constituting the first embodiment is shown, and, in the example shown, the +X-axis direction end of the orthogonal projection image of the first B deflection component and the -X-axis direction end of the orthogonal projection image of the second B deflection component are in contact.

[0260] A schematic diagram showing a third stage arrangement of the first A deflection member 31, the first B deflection member 32 and the first C deflection member 33 constituting the first deflection unit 30 and the second A deflection member 41, the second B deflection member 42 and the second C deflection member 43 constituting the second deflection unit 40 is shown in FIG. Figure 1A and Figure 1B In addition, Figure 2A A schematic diagram of the third stage arrangement of the first A deflecting member, the first B deflecting member and the first C deflecting member constituting the optical device of the first embodiment is shown in FIG. Figure 2B A conceptual diagram showing wave vectors and the like of the first A deflection unit, the first B deflection unit, and the first C deflection unit in the third stage arrangement is shown in FIG.

[0261] In the third stage arrangement, when the direction of the light incident on the first B deflection element 32 (in Figure 1A ” in the figure) and the direction of the light emitted from the first B deflection element 32 (indicated by “L1” in the figure) Figure 1A The angle formed by the direction of the light incident on the second B deflection element 42 (indicated by "L2" in Figure 1A ” in the figure) and the direction of the light emitted from the second B deflection element 42 (indicated by “L3” in the figure) Figure 1AWhen the angle formed by (indicated by "L4" in the figure) is ψ2,

[0262] Satisfies 90 degrees < ψ1, and

[0263] 90 degrees < ψ2

[0264] In addition, it is preferred to satisfy

[0265] 90 degrees < ψ1 ≤ 105 degrees, and

[0266] 90 degrees < ψ2 ≤ 105 degrees,

[0267] More preferably,

[0268] 90 degrees < ψ1 ≤ 100 degrees, and

[0269] 90 degrees<ψ2≤100 degrees.

[0270] Specifically, although not limited, it is preferred to satisfy

[0271] 99.5 (degrees) ≤ ψ1 = ψ2 ≤ 100.5 (degrees)

[0272] Specifically, it is only necessary to rotate the first B deflection member 32 and the second B deflection member 42 to optimize the inclination angle (oblique angle) Φ in the first B deflection member 32 and the second B deflection member 42, the pitch d of the grating surface, and the complementary angle θ of the incident angle on the interference fringes. Specifically, ψ1=ψ2=100 degrees. In addition, it is only necessary to rotate the first C deflection member 33 and the second C deflection member 43 to optimize the inclination angle (oblique angle) Φ in the first C deflection member 33 and the second C deflection member 43, the pitch d of the grating surface, and the complementary angle θ of the incident angle on the interference fringes.

[0273] exist Fig.17 The simulation result of the image obtained by such rotation of the deflection components 32, 42, 33 and 43 is shown in FIG. 1 , where it can be seen that the value of the FOV in the +X axis direction is greater than that in FIG. Fig. 16B The wider one, that is, Fig. 16B The area in (area D shown in white) is partly Fig.17 has been almost eliminated. Fig.18A and Fig.18B The simulation results of the light propagation states in the first light guide plate 21 and the second light guide plate 22 obtained in the optical device of the first embodiment are shown in FIG. Fig.19A and Fig.19B It is shown in Figure 1A The simulation results of the images obtained by the first deflection unit 30 and the second deflection unit 40 are shown.

[0274] Note that in the third stage arrangement, when the wave vector of the first A deflection element 31 is k v1-A , k v 1-A The X, Y, and Z components are k X 1-A , k Y 1-A and k Z 1-A , the wave vector of the second A deflection element 41 is k v 2-A And k v 2-A The X, Y, and Z components are k X 2-A , k Y 2-A and k Z 2-A hour,

[0275] k X 1-A +k X 2-A =0,

[0276] k Y 1-A =k Y 2-A ,as well as

[0277] k Z 1-A =k Z 2-A

[0278] In addition, when the wave vector of the first C deflection element 33 is k v 1-C , k v 1-C The X, Y, and Z components are k X 1-C , k Y 1-C and k Z 1-C , the wave vector of the second C deflection element 43 is k v 2-C And k v 2-C The X, Y, and Z components are k X 2-C , k Y 2-C and k Z 2-C hour,

[0279] k X 1-C +k X 2-C =0,

[0280] k Y 1-C =k Y 2-C ,as well as

[0281] k Z 1-C =k Z 2-C .

[0282] In addition, when the wave vector of the first B deflection element 32 is k v 1-B , k v 1-B The X, Y, and Z components are k X 1-B , k Y 1-B and k Z 1-B , the wave vector of the second B deflection element 42 is k v 2-B And k v 2-B The X, Y, and Z components are k X 2-B , k Y 2-B and k Z 2-B hour,

[0283] k X 1-B +k X 2-B =0,

[0284] k Y 1-B =k Y 2-B ,as well as

[0285] k Z 1-B =k Z 2-C

[0286] Here, it satisfies:

[0287] k v 1-A +k v 1-B +k v 1-C = 0, and

[0288] k v 2-A +k v 2-B +k v2-C =0.

[0289] exist Figure 2B In the example shown, the wave vector k is conceptually shown v 1-A , k v 1-B and k v 1-C The formed triangle is an unequal triangle, and the grating period d1 of the first A deflection unit, etc. has a value of, for example, 335.00nm, the grating period d2 of the first B deflection unit, etc. has a value of, for example, 359.26nm, and the grating period d3 of the first C deflection unit, etc. has a value of, for example, 384.22nm.

[0290] In addition, when the average diffraction efficiency of the first A deflecting member 31 is η for the light emitted from the image forming device 60, 1-A , the average diffraction efficiency of the first B deflection element 32 is η 1-B And the average diffraction efficiency of the first C deflection component 33 is η 1-C When η 1-B / η 1-A <1 and η 1-C / η 1-A <1, and when the average diffraction efficiency of the second A deflecting member 41 for the light emitted from the image forming device 60 is η 2-A The average diffraction efficiency of the second B deflection element 42 is η 2-B And the average diffraction efficiency of the second C deflection element 42 is η 2-C When η 2-B / η 2-A <1 and η 2-C / η 2-A <1.

[0291] like Fig. 6A As shown, the image forming device 60 (hereinafter, Fig. 6A The image forming device shown will be referred to as image forming device 60A) is an image forming device of a first configuration and has a plurality of pixels arranged in a two-dimensional matrix. Specifically, the image forming device 60A includes a reflective spatial light modulation device and a light source 71 including a light emitting diode (LED) that emits white light. Each image forming device 60A is entirely accommodated in a housing 70 (by Fig. 6A), the housing 70 has an opening (not shown), and light is emitted from the optical system (parallel light emitting optical system, collimating optical system) 74 through the opening. The housing 70 is attached to the upper part of the front part 51 by an attachment component not shown. The reflective spatial light modulation device includes a liquid crystal display device (LCD) 73 including an LCOS as a bulb. In addition, a polarized beam splitter 72 is provided, which reflects a portion of the light from the light source 71 and guides the light to the liquid crystal display device 73, and also passes a portion of the light reflected by the liquid crystal display device 73 and guides the light to the optical system 74. The liquid crystal display device 73 includes a plurality of (for example, 640×480) pixels (liquid crystal cells, liquid crystal display elements) arranged in a two-dimensional matrix. The polarized beam splitter 72 has a known configuration and structure. The non-polarized light emitted from the light source 71 collides with the polarized beam splitter 72. In the polarized beam splitter 72, the P polarized component passes through and is emitted to the outside of the system. On the other hand, the S polarized component is reflected by the polarized beam splitter 72, enters the liquid crystal display device 73, is reflected in the liquid crystal display device 73, and is emitted from the liquid crystal display device 73. Here, in the light emitted from the liquid crystal display device 73, the light emitted from the pixel displaying "white" contains a large amount of P polarized component, and the light emitted from the pixel displaying "black" contains a large amount of S polarized component. Therefore, in the light emitted from the liquid crystal display device 73 and colliding with the polarized beam splitter 72, the P polarized component passes through the polarized beam splitter 72 and is guided to the optical system 74. On the other hand, the S polarized component is reflected by the polarized beam splitter 72 and returns to the light source 71. The optical system 74 includes, for example, a convex lens, and, in order to generate parallel light, the image forming device 60A (more specifically, the liquid crystal display device 73) is arranged at a focal length position (position) in the optical system 74. The image emitted from the image forming device 60A is incident on the first A deflection component 31 and the second A deflection component 41 via a light guiding means not shown. The liquid crystal display device 73 includes a plurality of (for example, 640×480) pixels (liquid crystal cells, liquid crystal display elements) arranged in a two-dimensional matrix.

[0292] Or, if Figure 6B As shown, the image forming device 60 (hereinafter, Figure 6B The image forming device shown will be referred to as the image forming device 60B) includes an organic EL display device 75. An image emitted from the organic EL display device 75 passes through a convex lens 76, becomes parallel light, and proceeds to the first A deflection member 31 and the second A deflection member 41 via a light guiding means not shown. The organic EL display device 75 includes a plurality of (e.g., 640×480) pixels (organic EL elements) arranged in a two-dimensional matrix.

[0293] Or, if Figure 6CAs shown, an image forming apparatus 60 (hereinafter, Figure 6C The image forming apparatus shown will be referred to as image forming apparatus 60C) includes:

[0294] Light source 81;

[0295] a collimating optical system 82 that causes the light emitted from the light source 81 to become parallel light;

[0296] Scanning means 84 for scanning with parallel light emitted from the collimating optical system 82; and

[0297] A relay optical system 85 relays and emits the parallel light scanned by the scanning means 84. Note that the entire image forming apparatus 60C is housed in a housing 70 (composed of a Figure 6C In the embodiment of the present invention, the housing 70 has an opening (not shown), and light is emitted from the relay optical system 85 through the opening. The housing 70 is then attached to the upper portion of the front portion 51 by an attachment component not shown. The light source 81 includes a light emitting element (LED) that emits green light. The light emitted from the light source 81 is then incident on a collimating optical system 82 that has a positive optical power as a whole, and is emitted as parallel light. The parallel light is then reflected by a total reflection mirror 83, and for the parallel light, horizontal scanning and vertical scanning are performed by a scanning means 84 including a MEMS having a micromirror that can rotate in a two-dimensional direction to form a two-dimensional image, thereby generating a virtual pixel (whose number of pixels can be the same as, for example, the image forming device 60A). The light from the virtual pixel then passes through a relay optical system (parallel light emitting optical system) 85 formed by a known relay optical system, and is incident on the first A deflection component 31 and the second A deflection component 41 via a light guiding means not shown.

[0298] like Figure 7 As shown in the conceptual diagram in , the optical device includes an image forming device 60 (60A, 60B, 60C), and the image emitted from the image forming device 60 can be converged by lenses 74, 76, 85 (indicated by reference numeral 101 in the drawings) and incident on the first A deflection component 31 and the second A deflection component 41. The image emitted from the image forming device 60 is incident on the first A deflection component 31 and the second A deflection component 41 via the lens 101. At this time, the incident pupil diameter of the lens 101 in the X-axis direction is preferably larger than the width of the first A deflection component 31 and the second A deflection component 32 in the X-axis direction, and is more preferably the same as the width of the first A deflection component 31 and the second A deflection component 32 in the X-axis direction. Note that in Figure 7 In the figure, illustration of deflection members other than the first A deflection member 31 , the second A deflection member 41 , and the light guide plates 21 and 22 is omitted.

[0299] The frame 50 constituting the display device includes a front portion 51 (including an edge 51′) arranged in front of the observer, two temple portions 53 pivotally attached to both ends of the front portion 51 by hinges 52, and temple tips (also called tip units, earpieces, ear pads) 54 attached to the tips of each temple portion 53. In addition, a nose pad 51″ is attached. That is, the assembly of the frame 50 and the nose pad 51″ has substantially the same structure as ordinary glasses. In addition, as described above, each shell 70 is attached to the front portion 51 by an attachment component not shown. The frame 50 includes metal or plastic. Note that each shell 70 can be detachably attached to the front portion 51 by an attachment component.

[0300] Furthermore, a wiring (signal line or power line, etc., not shown in part) 55 extending from one of the image forming devices 60 extends from the tip portion of the temple tip 54 to the outside via the temple portion 53 and the inside of the temple tip 54, and is connected to a control device (control circuit, control means) 58. Furthermore, each image forming device 60 includes an earphone portion 56, and a wiring 57 for the earphone portion extending from each image forming device 60 extends from the tip portion of the temple tip 54 to the earphone portion 56 via the inside of the temple portion 53 and the inside of the temple tip 54. More specifically, the wiring 57 for the earphone portion (not shown in part) extends from the tip portion of the temple tip 54 to the earphone portion 56 so as to surround the back of the auricle (ear auricle). By such a configuration, a neat display device can be obtained without giving the impression that the earphone portion 56 and the wiring 57 for the earphone portion are randomly arranged.

[0301] The optical device of the first embodiment, the optical device constituting the image display device of the first embodiment, and the optical device constituting the display device of the first embodiment include a first deflection unit and a second deflection unit arranged on a first light guide plate and a second light guide plate, and a portion (for example, half) of the image emitted from the image forming device is incident on the first deflection unit, and at least the remaining portion (for example, the remaining half) of the image emitted from the image forming device is incident on the second deflection unit. That is, it is a kind of image divided by the first A deflection component and the second A deflection component. Then, these divided images are finally emitted and synthesized from the first deflection unit and the second deflection unit, that is, the images emitted from the first C deflection component and the second C deflection component are synthesized and reach the pupil of the observer. Therefore, the horizontal viewing angle of the image in the conventional optical device can be doubled, for example. That is, an optical device having a configuration and structure capable of further widening the viewing angle, an image display device including such an optical device, and a display device including such an image display device can be provided. In addition, since the first direction and the second direction are opposite directions and are not parallel, further widening of the viewing angle can be achieved.

[0302] In the case where the first deflection unit and the second deflection unit are arranged on one light guide plate instead of the first light guide plate and the second light guide plate, there is a risk that the traveling light diffracted and reflected by the first deflection unit and totally reflected in the light guide plate enters the second deflection unit and is diffracted and reflected by the second deflection unit. However, by arranging the first deflection unit on the first light guide plate and arranging the second deflection unit on the second light guide plate, the light diffracted and reflected by the first deflection unit and traveling by total reflection in the light guide plate does not enter the second deflection unit, and the occurrence of such a problem can be prevented.

[0303] [Second embodiment]

[0304] The second embodiment is a modification of the first embodiment. In the first embodiment, it is assumed that the +X axis and the -X axis are located in a horizontal plane. On the other hand, in the second embodiment, the +X axis and the -X axis are located in a vertical plane. Fig.13 and Fig.14 , schematic diagrams of a first light guide plate and a first deflecting unit and a second light guide plate and a second deflecting unit constituting the optical device of the second embodiment are shown. Fig.13 and Fig.14 A conceptual diagram of an optical device constituting an image display device for the right eye viewed from the front is shown, wherein the observer's ear is located on the right-hand side of the diagram and the observer's nose is located on the left-hand side of the diagram. That is, the observer's nose is located in the Y-axis (specifically, -Y-axis) direction, and the observer's ear is located in the Y-axis (specifically, +Y-axis) direction. The light incident on the light guide plate travels substantially horizontally from the first A deflection member and the second A deflection member to the first B deflection member and the second B deflection member (that is, the Y-axis is located in the horizontal direction). In addition to the above points, the optical device of the second embodiment may have a configuration and structure similar to that of the optical device of the first embodiment, so a detailed description thereof will be omitted. Note that it is only necessary to determine whether to adopt the first embodiment or the second embodiment based on the specifications required for the optical device, the image display device, and the display device.

[0305] Although the present disclosure is described above based on preferred embodiments, the present disclosure is not limited to these embodiments. The configurations and structures of the display device (head-mounted display), image display device, and optical device described in the embodiments are examples and can be appropriately changed. The deflection component can also be a reflective blazed diffraction grating element. In addition, the display device of the present disclosure can also be used as a stereoscopic display device. In this case, if necessary, it is only necessary to detachably attach the polarizing plate or polarizing film to the optical device, or to attach the polarizing plate or polarizing film to the optical device. The image display device may include a light control device. That is, the optical device may overlap with at least a portion of the light control device. More specifically, it is preferred that at least the first C deflection component of the optical device overlaps with the light control device.

[0306] In the first embodiment, although an example is described in which light emitted from the first A deflecting member and the second A deflecting member travels downward from the light guide plate, a mode may be adopted in which light travels upward from the light guide plate.

[0307] On the material constituting one volume holographic diffraction grating, a first A deflection member and a first B deflection member may be formed, a first A deflection member and a first C deflection member may be formed, a first B deflection member and a first C deflection member may be formed, or a first A deflection member, a first B deflection member, a first C deflection member, a first B deflection member, a first C deflection member, a first B deflection member, etc. may be formed. A holographic area may be formed on the light guide plate based on an imprinting method or an etching method.

[0308] As will be referred to below Fig.15A , Fig. 15B , Fig. 15C , Fig.15D , Fig.15E , Fig.15F , Figure 15G and Fig.15H As described above, the conceptual diagram of the modified example of the optical device described in the first embodiment can also be modified. Fig.15A As shown, the first A deflection component 31a including a transmission type volume holographic diffraction grating can be arranged on the first surface of the light guide plate, and the first B deflection component 32b and the first C deflection component 33b including a reflection type volume holographic diffraction grating can be arranged on the second surface of the light guide plate. Fig. 15B As shown, the first B deflection component 32a and the first C deflection component 33a including the transmission type volume hologram diffraction grating can be arranged on the first surface of the light guide plate, and the first A deflection component 31b including the reflection type volume hologram diffraction grating can be arranged on the second surface of the light guide plate. Fig. 15C As shown, the first A deflection member 31a, the first B deflection member 32a and the first C deflection member 33a including the transmission type volume hologram diffraction grating may be arranged on the first surface of the light guide plate. Fig.15D As shown, the first A deflection component 31a including the transmission type volume holographic diffraction grating can be arranged on the first surface of the light guide plate, and the first A deflection component 31b including the reflection type volume holographic diffraction grating, the first B deflection component 32b and the first C deflection component 33b can be arranged on the second surface of the light guide plate. Fig.15EAs shown, the first A deflection component 31a including the transmission type volume holographic diffraction grating, the first B deflection component 32a and the first C deflection component 33a can be arranged on the first surface of the light guide plate, and the first A deflection component 31b including the reflection type volume holographic diffraction grating can be arranged on the second surface of the light guide plate. Or, as Fig.15F As shown, the first B deflection component 32a and the first C deflection component 33a including the transmission type volume holographic diffraction grating can be arranged on the first surface of the light guide plate, and the first A deflection component 31b, the first B deflection component 32b and the first C deflection component 33b including the reflection type volume holographic diffraction grating can be arranged on the second surface of the light guide plate. Or, as Figure 15G As shown, the first A deflection component 31a, the first B deflection component 32a and the first C deflection component 33a including the transmission type volume hologram diffraction grating can be arranged on the first surface of the light guide plate, and the first B deflection component 32b and the first C deflection component 33b including the reflection type volume hologram diffraction grating can be arranged on the second surface of the light guide plate. Or, as Fig.15H As shown, the first A deflection component 31a, the first B deflection component 32a and the first C deflection component 33a including the transmission type volume holographic diffraction grating can be arranged on the first surface of the light guide plate, and the first A deflection component 31b, the first B deflection component 32b and the first C deflection component 33b including the reflection type volume holographic diffraction grating can be arranged on the second surface of the light guide plate.

[0309] Specifically, the following modes may be adopted, wherein the light control device includes:

[0310] a first substrate;

[0311] a second substrate opposite to the first substrate;

[0312] a first transparent electrode disposed on a surface of the first substrate opposite to the second substrate;

[0313] A second transparent electrode disposed on an opposite surface of the second substrate to the first substrate; and

[0314] The light control layer is sandwiched between the first transparent electrode and the second transparent electrode. Note that when the light control device is operating, for example, when the light control device is operating, a voltage higher than the voltage of the second transparent electrode is applied to the first transparent electrode.

[0315] A mode in which the light control layer includes a shutter that applies a color change of a substance generated by a redox reaction of an inorganic or organic electrochromic material may be adopted. Specifically, a mode in which the light control layer includes an inorganic or organic electrochromic material may be adopted, and a mode in which the light control layer has a plurality of layers such as a WO3 layer / Ta2O5 layer / Ir X Sn 1-X O layer of inorganic electrochromic material layer stacked structure or such as WO3 layer / Ta2O5 layer / IrO x The stacking structure of the inorganic electrochromic material layer is shown in FIG. 1 . A MoO3 layer or a V2O5 layer can be used instead of the WO3 layer. In addition, as IrO x Instead of the layer, a ZrO2 layer and a zirconium phosphate layer can be used, or a Prussian blue complex / nickel-substituted Prussian blue complex can be used. As the organic electrochromic material, for example, the electrochromic materials disclosed in Japanese Patent Application Publication No. 2014-111710 and Japanese Patent Application Publication No. 2014-159385 can also be used.

[0316] Alternatively, a mode may be adopted in which the light control layer includes an electrophoretic dispersion liquid, and a mode may be adopted in which the light control device is a light shutter of an electrodeposition method (electrodeposition / electric field deposition) applying an electrodeposition / dissociation phenomenon generated by a reversible redox reaction of a metal (e.g., silver particles), i.e., the light control layer includes an electrolyte containing metal ions.

[0317] Here, the electrophoretic dispersion includes a large number of charged electrophoretic particles and a dispersion medium having a color different from that of the electrophoretic particles. For example, when the first transparent electrode is patterned and the second transparent electrode is not patterned (referred to as a solid electrode configuration) and the electrophoretic particles are negatively charged, when a relatively negative voltage is applied to the first transparent electrode and a relatively positive voltage is applied to the second transparent electrode, the negatively charged electrophoretic particles migrate to cover the second transparent electrode. Therefore, the light shielding rate in the light control device is a high value. On the other hand, on the contrary, when a relatively positive voltage is applied to the first transparent electrode and a relatively negative voltage is applied to the second transparent electrode, the electrophoretic particles migrate to cover the first transparent electrode. Therefore, the light shielding rate in the light control device is a low value. By appropriately applying such a transparent electrode, the light shielding rate in the light control device can be controlled. The voltage can be direct current or alternating current. The shape of the patterned first transparent electrode only needs to make it possible for the value of the light shielding rate in the light control device to be optimized when the electrophoretic particles migrate to cover the first transparent electrode and the light shielding rate in the light control device is a low value, and only needs to be determined by performing various tests. If necessary, an insulating layer can be formed on the transparent electrode. Examples of the material constituting the insulating layer include colorless and transparent insulating resins, and specific examples thereof include acrylic resins, epoxy resins, fluororesins, silicone resins, polyimide resins, and polystyrene resins.

[0318] As the material forming the transparent first substrate and the second substrate constituting the light control device, specifically, transparent glass substrates such as soda lime glass or white plate glass, plastic substrates, plastic sheets and plastic films can be cited. Here, as plastics, polyethylene terephthalate, polyethylene naphthalate, polycarbonate, cellulose ester (such as cellulose acetate), fluorine-containing polymers (such as copolymers of polyvinylidene fluoride or polytetrafluoroethylene and hexafluoropropylene), polyethers (such as polyoxymethylene), polyolefins (such as polyacetaldehyde, polystyrene, polyethylene, polypropylene, methylpentene polymers), polyimides (such as polyamideimide or polyetherimide), polyamides, polyethersulfones, polyphenylene sulfide, polyvinylidene fluoride, tetraacetyl cellulose, brominated phenoxy, polyarylate or polysulfone, etc. Plastic sheets and plastic films may have rigidity that is not easy to bend, or may have flexibility. In the case where the first substrate and the second substrate are formed by transparent plastic substrates, a barrier layer composed of an inorganic material or an organic material may be formed on the inner surface of the substrate.

[0319] The first substrate and the second substrate are sealed and joined at the outer edge portion by a sealing member. As the sealing member also called a sealant, various resins of a heat-curing type, a light-curing type, a moisture-curing type, and an anaerobic-curing type, such as an epoxy resin, a polyurethane resin, an acrylic resin, a vinyl acetate resin, an ene-thiol resin, a silicone resin, or a modified polymer resin, etc. can be used.

[0320] If one of the substrates constituting the light control device is formed to also serve as a component of the optical device (specifically, a protective component arranged so that the volume hologram diffraction grating is not in direct contact with the atmosphere), the weight of the entire display device can be reduced, and there is no risk of causing discomfort to a user of the display device. Note that a configuration in which the other substrate is thinner than one substrate can be adopted.

[0321] The first transparent electrode may be patterned or not. The second transparent electrode may be patterned or not. As materials constituting the first transparent electrode and the second transparent electrode, specifically, indium tin oxide composite oxides (including ITO, indium tin oxide, tin-doped In2O3, crystalline ITO and amorphous ITO) and fluorine-doped SnO2 (FTO), F-doped In2O3 (IFO), antimony-doped SnO2 (ATO), SnO2, ZnO (including Al-doped ZnO and B-doped ZnO), indium zinc oxide (IZO), spinel-type oxides, oxides with YbFe2O4 structure or conductive polymers (such as polyaniline, polypyrrole and polythiophene), etc. can be cited, but not limited to these materials, and two or more of these materials can be combined and used. The first transparent electrode and the second transparent electrode can be formed based on physical vapor deposition (PVD method) such as a vacuum deposition method and a sputtering method, various chemical vapor deposition methods (CVD methods), and various coating methods, and composition can be performed by any method such as an etching method, a stripping method, and a method using various masks.

[0322] A mode in which the light control device is arranged at the front may be adopted. Then, in this case, a mode in which the front has an edge and the light control device is embedded in the edge may be adopted. In addition, in the display device of the present disclosure including the above-mentioned various preferred modes, the optical device and the light control device may be arranged in sequence from the observer side or the light control device and the optical device may be arranged in sequence.

[0323] A mode may be adopted in which an illuminance sensor (environmental illuminance measuring sensor) that measures the illuminance of the environment in which the display device is placed is further provided, and the light shielding rate of the light control device is controlled based on the measurement result of the illuminance sensor (environmental illuminance measuring sensor). Alternatively, a mode may be adopted in which an illuminance sensor (environmental illuminance measuring sensor) that measures the illuminance of the environment in which the display device is placed is further provided, and the illuminance of the image formed by the image forming device is controlled based on the measurement result of the illuminance sensor (environmental illuminance measuring sensor). These modes may be combined.

[0324] Alternatively, a mode may be adopted in which a second illuminance sensor (for convenience, it may be referred to as a "transmitted light illuminance measuring sensor") that measures illuminance based on light from an external environment passing through a light control device is further provided and controls the light shielding rate of the light control device based on the measurement result of the (transmitted light illuminance measuring sensor). Alternatively, a mode may be adopted in which a second illuminance sensor (transmitted light illuminance measuring sensor) that measures illuminance based on light from an external environment passing through a light control device is further provided and controls the light shielding rate of an image formed by an image forming device based on the measurement result of the second illuminance sensor (transmitted light illuminance measuring sensor). Note that it is desirable to adopt a mode in which the second illuminance sensor (transmitted light illuminance measuring sensor) is arranged on the observer side of the optical device. At least two second illuminance sensors (transmitted light illuminance measuring sensors) may be arranged to measure illuminance based on light that has passed through a portion with a high light shielding rate, and to measure illuminance based on light that has passed through a portion with a low light shielding rate. These modes may be combined. In addition, these modes may be combined with a mode in which control is performed based on the measurement result of the above-mentioned illuminance sensor (environmental illuminance measuring sensor).

[0325] The illuminance sensor (ambient illuminance measuring sensor, transmitted light illuminance measuring sensor) only needs to include a known illuminance sensor, and control of the illuminance sensor only needs to be performed based on a known control circuit.

[0326] A configuration in which the maximum light transmittance of the light control device is 50% or higher and the minimum light transmittance of the light control device is 30% or lower may be adopted. Note that the upper limit of the maximum light transmittance of the light control device may be 99%, and the lower limit of the minimum light transmittance of the light control device may be 1%. Here, the following relationship exists:

[0327] (Light transmittance) = 1-(light blocking rate)

[0328] The connector can be attached to the light control device (specifically, the connector can be attached to the first transparent electrode or the second transparent electrode), and the light control device only needs to be electrically connected to a control circuit that controls the shading rate of the light control device (for example, a light control device control circuit included in a control device for controlling an image forming device) through the connector and wiring.

[0329] In some cases, a configuration may be adopted in which the light passing through the light control device can be configured to be colored with a desired color by the light control device. Then, in this case, a mode in which the color to be taken by the light control device is variable may be adopted, or a mode in which the color to be taken by the light control device is fixed may be adopted. Note that in the former case, for example, it is only necessary to adopt a mode in which a light control device with red as the color, a light control device with green as the color, and a light control device with blue as the color are stacked. In addition, in the latter case, although not limited to this, brown may be cited as the color to be taken by the light control device.

[0330] The observer observes the brightness of the light passing through the light control device and the optical device, and the observer can manually control and adjust the shading rate by operating a switch, button, dial, slider or knob, etc., or can control and adjust the shading rate based on the measurement result of the above-mentioned second illuminance sensor (transmitted light illuminance measuring sensor), which measures the illuminance based on the light passing through the light control device from the external environment. Note that, specifically, it is only necessary to control and adjust the shading rate by controlling the voltage applied to the first transparent electrode and the second transparent electrode. At least two second illuminance sensors (transmitted light illuminance measuring sensors) can be arranged to measure the illuminance based on the light that has passed through the part with a high shading rate and to measure the illuminance based on the light that has passed through the part with a low shading rate. The display device can be provided with one image display device or two display devices. In the case of setting two image display devices, the shading rate in one light control device can be equal to the shading rate in another light control device by adjusting the voltage applied to the first transparent electrode and the second transparent electrode by one light control device and the other light control device, respectively. The shading rate of one light control device and the shading rate of another light control device can be controlled based on, for example, the measurement result of the second illuminance sensor (transmitted light illuminance measuring sensor) that measures illuminance based on light transmitted from the external environment through the light control device as described above, or an observer can observe the brightness of light passing through one light control device and the optical device and the brightness of light passing through the other light control device and the optical device, and the observer can manually control and adjust the shading rate by operating a switch, button, dial, slider or knob, etc. A test pattern can be displayed on the optical device while the shading rate is adjusted.

[0331] Note that the present disclosure can also adopt the following configurations.

[0332] [A01]<<Optical Equipment>>

[0333] An optical device for incident, guiding and emitting light emitted from an image forming device, the optical device comprising a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate,

[0334] The first deflection unit includes a first A deflection component, a first B deflection component and a first C deflection component.

[0335] The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member,

[0336] A portion of the light emitted from the image forming device is incident on the first A deflecting member,

[0337] The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer,

[0338] at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member,

[0339] The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and

[0340] When the propagation direction of light deflected by the first B deflection component in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of light deflected by the second B deflection component in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction.

[0341] [A02] The optical device according to [A01], wherein the first light guide plate and the second light guide plate are juxtaposed.

[0342] [A03] An optical device according to [A01] or [A02], wherein:

[0343] The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin,

[0344] In the XYZ Cartesian coordinate system through the origin,

[0345] When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction,

[0346] The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and

[0347] When the axis orthogonal to the X-axis and the Z-axis is the Y-axis,

[0348] The first deflection unit and the second deflection unit are arranged at positions symmetrical with respect to the YZ plane.

[0349] [A04] An optical device according to [A03], wherein:

[0350] The first deflection unit is arranged in a state of being rotated in a first rotation direction in a counterclockwise direction or a clockwise direction around the Z axis, and

[0351] The second deflection unit is arranged in a state of being rotated around the Z axis in a second rotation direction of the clockwise direction or the counterclockwise direction.

[0352] [A05] An optical device according to [A04], wherein:

[0353] When the rotation angle in the first rotation direction is based on the +X axis, and the rotation angle in the second rotation direction is hour,

[0354] satisfy

[0355] [A06] An optical device according to [A05], wherein:

[0356]

[0357] [A07] The optical device according to any one of [A03] to [A06], wherein:

[0358] When the angle formed by the direction of light incident on the first B deflection element and the direction of light emitted from the first B deflection element is ψ1 and the angle formed by the direction of light incident on the second B deflection element and the direction of light emitted from the second B deflection element is ψ2, it is satisfied:

[0359] 90 degrees < ψ1, and

[0360] 90 degrees <ψ2.

[0361] [A08] An optical device according to [A07], wherein:

[0362] Satisfies 90 degrees < ψ1 ≤ 105 degrees, and

[0363] 90 degrees<ψ2≤105 degrees.

[0364] [A09] An optical device according to [A07] or [A08], wherein:

[0365] Satisfies ψ1=ψ2.

[0366] [A10] The optical device according to any one of [A01] to [A09], wherein:

[0367] The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin,

[0368] In the XYZ Cartesian coordinate system through the origin,

[0369] When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction,

[0370] The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and

[0371] When the axis orthogonal to the X-axis and the Z-axis is the Y-axis,

[0372] When the light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the first light guide plate, the angle (θ) formed by the orthogonally projected image and the X-axis is X ) is less than 90 degrees.

[0373] [A11] The optical device according to [A10], wherein:

[0374] Satisfies 70(degrees)≤θ0<90(degrees).

[0375] [A12] An optical device according to [A10] or [A11], wherein when a light beam emitted from the center point of an image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto an XY plane, an angle (θ X ) is greater than or equal to -20 degrees and less than or equal to 20 degrees.

[0376] [A13] An optical device according to any one of [A03] to [A12], wherein an orthogonal projection image of the first B deflection component when the first B deflection component is orthogonally projected onto the first light guide plate (XY plane) partially overlaps with an orthogonal projection image of the second B deflection component when the second B deflection component is orthogonally projected onto the first light guide plate (XY plane).

[0377] [A14] An optical device according to [A013], wherein an end of the first B deflection component orthogonal projection image in the +X axis direction overlaps an end of the second B deflection component orthogonal projection image in the -X axis direction.

[0378] [A15] The optical device according to any one of [A03] to [A14], wherein:

[0379] The first A deflection element and the second A deflection element include volume holographic diffraction gratings, and

[0380] When the wave vector of the first A deflection element is k v 1-A , k v 1-A The X, Y, and Z components are k X 1-A , k Y 1-A and k Z 1-A , the wave vector of the second A deflection element is k v 2-A And k v 2-A The X, Y, and Z components are k X 2-A , k Y 2-A and k Z 2-A hour,

[0381] Satisfy k X 1-A +k X 2-A =0,

[0382] k Y 1-A =k Y 2-A ,as well as

[0383] k Z 1-A =k Z 2-A .

[0384] [A16] The optical device according to [A15], wherein:

[0385] The first C-deflection element and the second C-deflection element include volume holographic diffraction gratings, and

[0386] When the wave vector of the first C deflection element is k v 1-C , k v 1-C The X, Y, and Z components are k X 1-C , k Y 1-C , k Z 1-C , the wave vector of the second C deflection element is kv 2-C And k v 2-C The X, Y, and Z components are k X 2-C , k Y 2-C , k Z 2-C hour,

[0387] Satisfy k X 1-C +k X 2-C =0,

[0388] k Y 1-C =k Y 2-C ,as well as

[0389] k Z 1-C =k Z 2-C .

[0390] [A17] The optical device according to [A16], wherein:

[0391] The first B deflection element and the second B deflection element include volume holographic diffraction gratings, and

[0392] When the wave vector of the first B deflection element is k v 1-B , k v 1-B The X, Y, and Z components are k X 1-B , k Y 1-B , k Z 1-B , the wave vector of the second B deflection element is k v 2-B And k v 2-B The X, Y, and Z components are k X 2-B , k Y 2-B , k Z 2-B hour,

[0393] Satisfy k X 1-B +k X 2-B =0,

[0394] k Y 1-B =kY 2-B ,as well as

[0395] k Z 1-B =k Z 2-C .

[0396] [A18] The optical device according to [A17], wherein:

[0397] Satisfy k v 1-A +k v 1-B +k v 1-C = 0, and

[0398] k v 2-A +k v 2-B +k v 2-C =0.

[0399] [A19] The optical device according to any one of [A01] to [A18], wherein:

[0400] When the first A deflection element, the first B deflection element and the first C deflection element include volume holographic diffraction gratings, and

[0401] With respect to light emitted from the image forming device, the average diffraction efficiency of the first A deflecting member is η 1-A The average diffraction efficiency of the first B deflection element is η 1-B , the average diffraction efficiency of the first C deflection element is η 1-C hour,

[0402] Satisfy η 1-B / η 1-A <1, and

[0403] η 1-C / η 1-A <1.

[0404] Furthermore, when the second A deflection element, the second B deflection element and the second C deflection element include volume holographic diffraction gratings, and

[0405] With respect to light emitted from the image forming device, the average diffraction efficiency of the second A deflecting member is η 2-A The average diffraction efficiency of the second B deflection element is η 2-B And the average diffraction efficiency of the second C deflection element is η 2-C hour,

[0406] Satisfy η 2-B / η 2-A <1, and

[0407] η 2-C / η 2-A <1.

[0408] [B01]<<Image Display Device>>

[0409] An image display device, comprising:

[0410] image forming apparatus; and

[0411] an optical device for incident, guiding and emitting light emitted from an image forming device,

[0412] The optical device includes a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate.

[0413] The first deflection unit comprises a first A deflection member, a first B deflection member and a first C deflection member,

[0414] The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member,

[0415] A portion of the light emitted from the image forming device is incident on the first A deflecting member,

[0416] The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer,

[0417] at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member,

[0418] The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and

[0419] When the propagation direction of light deflected by the first B deflection component in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of light deflected by the second B deflection component in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction.

[0420] [B02] <<Image Display Device>>

[0421] An image display device, comprising:

[0422] image forming apparatus; and

[0423] an optical device for incident, guiding and emitting light emitted from an image forming device,

[0424] The optical device includes the optical device according to any one of [A01] to [A19].

[0425] [C01]<<Display Device>>

[0426] A display device, comprising:

[0427] a frame that attaches to the viewer's head; and

[0428] an image display device attached to the frame,

[0429] The image display device includes an image forming device and an optical device for incident, guiding and emitting light emitted from the image forming device.

[0430] The optical device includes a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate.

[0431] The first deflection unit comprises a first A deflection member, a first B deflection member and a first C deflection member,

[0432] The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member,

[0433] A portion of the light emitted from the image forming device is incident on the first A deflecting member,

[0434] The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer,

[0435] at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member,

[0436] The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and

[0437] When the propagation direction of light deflected by the first B deflection component in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of light deflected by the second B deflection component in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction.

[0438] [C02]<<Display Device>>

[0439] A display device, comprising:

[0440] a frame that attaches to the viewer's head; and

[0441] an image display device attached to the frame,

[0442] The image display device includes an image forming device and an optical device for incident, guiding and emitting light emitted from the image forming device, and

[0443] The optical device includes the optical device according to any one of [A01] to [A19].

[0444] List of Reference Numerals

[0445] 10 Optical equipment

[0446] 11 Image display device

[0447] 20 Light guide plate

[0448] 21 First surface of light guide plate

[0449] 22 Second surface of light guide plate

[0450] 23 Support components

[0451] 31 1st A deflection component

[0452] 32 1st B deflection unit

[0453] 33 First C deflection component

[0454] 41 Second A deflection component

[0455] 42 second B deflection member

[0456] 43 Second C deflection component

[0457] 50 Frames

[0458] 51 front

[0459] 51′ Edge

[0460] 51″ Nose Pad

[0461] 52 Hinge

[0462] 53 Temple part

[0463] 54 temple tip

[0464] 55 Wiring (signal lines or power lines, etc.)

[0465] 56 Headphones

[0466] 57 Wiring for headphone section

[0467] 58 Control equipment (control circuit, control means)

[0468] 60, 60A, 60B, 60C Image forming device

[0469] 70 Shell

[0470] 71 Light Source

[0471] 72 Polarizing Beam Splitter (PBS)

[0472] 73 Liquid crystal display device (LCD)

[0473] 74 Optical system (parallel light emission optical system, collimation optical system)

[0474] 75 Organic EL display device

[0475] 76 Convex lens

[0476] 81 Light Source

[0477] 82 Collimation Optical System

[0478] 83 Total Reflection Mirror

[0479] 84 Scanning methods

[0480] 85 Relay optical system

[0481] 90 The Observer's Pupil

Claims

1. An optical device for incident, guiding and emitting light emitted from an image forming device, the optical device comprising a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate, in, The first deflection unit comprises a first A deflection member, a first B deflection member and a first C deflection member, The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member, A portion of the light emitted from the image forming device is incident on the first A deflecting member, The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer, at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member, The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and When the propagation direction of the light deflected by the first B deflection member in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of the light deflected by the second B deflection member in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction, The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin, In the XYZ Cartesian coordinate system through the origin, When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction, The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and When the axis orthogonal to the X-axis and the Z-axis is the Y-axis, When a light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the first light guide plate, an angle formed by the orthogonally projected image and the X-axis is less than 90 degrees.

2. The optical device according to claim 1, wherein The first light guide plate and the second light guide plate are juxtaposed.

3. The optical device according to claim 1, wherein: The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin, In the XYZ Cartesian coordinate system through the origin, When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction, The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and When the axis orthogonal to the X-axis and the Z-axis is the Y-axis, The first deflection unit and the second deflection unit are arranged at positions symmetrical with respect to the YZ plane.

4. The optical device according to claim 3, wherein: The first deflection unit is arranged in a state of being rotated in a first rotation direction in a counterclockwise direction or a clockwise direction around the Z axis, and The second deflection unit is arranged in a state of being rotated around the Z axis in a second rotation direction of the clockwise direction or the counterclockwise direction.

5. The optical device according to claim 4, wherein: When the rotation angle in the first rotation direction is based on the +X axis, and the rotation angle in the second rotation direction is hour, satisfy 6. The optical device according to claim 5, wherein:

7. The optical device according to claim 3, wherein: When the angle formed by the direction of light incident on the first B deflection element and the direction of light emitted from the first B deflection element is ψ1 and the angle formed by the direction of light incident on the second B deflection element and the direction of light emitted from the second B deflection element is ψ2, it is satisfied: 90 degrees < ψ1, and 90 degrees <ψ2.

8. The optical device according to claim 7, wherein: Satisfies 90 degrees < ψ1 ≤ 105 degrees, and 90 degrees<ψ2≤105 degrees.

9. The optical device according to claim 7, wherein: Satisfies ψ1=ψ2.

10. The optical device according to claim 3, wherein: The first B deflection member orthogonal projection image when the first B deflection member is orthogonally projected onto the first light guide plate partially overlaps with the second B deflection member orthogonal projection image when the second B deflection member is orthogonally projected onto the first light guide plate.

11. The optical device according to claim 10, wherein: The end portion of the first B deflection means orthogonal projection image in the +X axis direction overlaps with the end portion of the second B deflection means orthogonal projection image in the -X axis direction.

12. The optical device according to claim 3, wherein: The first A deflection element and the second A deflection element include volume holographic diffraction gratings, and When the wave vector of the first A deflection element is k v 1-A , k v 1-A The X, Y, and Z components are k X 1-A , k Y 1-A and k Z 1-A , the wave vector of the second A deflection element is k v 2-A And k v 2-A The X, Y, and Z components are k X 2-A , k Y 2-A and k Z 2-A hour, Satisfy k X 1-A +k X 2-A =0, k Y 1-A =k Y 2-A ,as well as k Z 1-A =k Z 2-A 。 13. The optical device according to claim 12, wherein: The first C-deflection element and the second C-deflection element include volume holographic diffraction gratings, and When the wave vector of the first C deflection element is k v 1-C , k v 1-C The X, Y, and Z components are k X 1-C , k Y 1-C and k Z 1-C , the wave vector of the second C deflection element is k v 2-C And k v 2-C The X, Y, and Z components are k X 2-C , k Y 2-C and k Z 2-C hour, Satisfy k X 1-C +k X 2-C =0, k Y 1-C =k Y 2-C ,as well as k Z 1-C =k Z 2-C 。 14. The optical device according to claim 13, wherein: The first B deflection element and the second B deflection element include volume holographic diffraction gratings, and When the wave vector of the first B deflection element is k v 1-B , k v 1-B The X, Y, and Z components are k X 1-B , k Y 1-B and k Z 1-B , the wave vector of the second B deflection element is k v 2-B And k v 2-B The X, Y, and Z components are k X 2-B , k Y 2-B and k Z 2-B hour, Satisfy k X 1-B +k X 2-B =0, k Y 1-B =k Y 2-B ,as well as k Z 1-B =k Z 2-C 。 15. The optical device according to claim 14, wherein: Satisfy k v 1-A +k v 1-B +k v 1-C = 0, and k v 2-A +k v 2-B +k v 2-C =0。 16. An image display device, comprising: Image forming equipment; and an optical device for incident, guiding and emitting light emitted from an image forming device, The optical device includes a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate. The first deflection unit comprises a first A deflection member, a first B deflection member and a first C deflection member, The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member, A portion of the light emitted from the image forming device is incident on the first A deflecting member, The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer, at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member, The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and When the propagation direction of the light deflected by the first B deflection member in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of the light deflected by the second B deflection member in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction, The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin, In the XYZ Cartesian coordinate system through the origin, When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction, The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and When the axis orthogonal to the X-axis and the Z-axis is the Y-axis, When a light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the first light guide plate, an angle formed by the orthogonally projected image and the X-axis is less than 90 degrees.

17. A display device comprising: a frame attached to the observer's head; and an image display device attached to the frame, The image display device includes an image forming device and an optical device for incident, guiding and emitting light emitted from the image forming device. The optical device includes a first light guide plate and a second light guide plate, and a first deflection unit disposed on the first light guide plate and a second deflection unit disposed on the second light guide plate. The first deflection unit comprises a first A deflection member, a first B deflection member and a first C deflection member, The second deflection unit comprises a second A deflection member, a second B deflection member and a second C deflection member, A portion of the light emitted from the image forming device is incident on the first A deflecting member, The light incident on the first A deflection component is deflected by the first A deflection component, totally reflected in the first light guide plate and incident on the first B deflection component, deflected by the first B deflection component, totally reflected in the first light guide plate and incident on the first C deflection component, deflected by the first C deflection component, and emitted toward the pupil of the observer, at least a remaining portion of the light emitted from the image forming device is incident on the second A deflecting member, The light incident on the second A deflection component is deflected by the second A deflection component, totally reflected in the second light guide plate, incident on the second B deflection component, deflected by the second B deflection component, totally reflected in the second light guide plate, incident on the second C deflection component, deflected by the second C deflection component, and emitted to the pupil of the observer, and When the propagation direction of the light deflected by the first B deflection member in the first light guide plate is orthogonally projected onto the first light guide plate as a first direction and the propagation direction of the light deflected by the second B deflection member in the second light guide plate is orthogonally projected onto the first light guide plate as a second direction, the first direction is opposite to the second direction, The point on the first light guide plate where the light beam emitted from the center point of the image forming area of ​​the image forming device collides with the first light guide plate is the origin, In the XYZ Cartesian coordinate system through the origin, When the axis including the bisector toward the first direction is the +X axis, the bisector is the bisector of an acute angle within the angle between a straight line passing through the origin and parallel to the first direction and a straight line passing through the origin and parallel to the second direction, The axis passing through the origin and perpendicular to the first light guide plate is the Z axis, and When the axis orthogonal to the X-axis and the Z-axis is the Y-axis, When a light beam emitted from the center point of the image forming area of ​​the image forming device and incident on the origin is orthogonally projected onto the first light guide plate, an angle formed by the orthogonally projected image and the X-axis is less than 90 degrees.

Images