Virtual image display device

Abstract

Virtual image display device. Reduce the unevenness of the brightness of the displayed virtual image. In the virtual image display device (110), the first exit diffraction grating (541) and the second exit diffraction grating (542) overlap when viewed from the exit pupil (EP), the area of the first exit diffraction grating (541) that exits the first image light (G1) is different from the area of the second exit diffraction grating (542) that exits the second image light (G2), so that a large difference between the optical path from the first display element (31a) to the first exit diffraction grating (541) and the optical path from the second display element (32a) to the second exit diffraction grating (542) can be avoided, and the unevenness of the brightness of the virtual image displayed due to the increase in the brightness difference between the first image light (G1) exiting from the first exit diffraction grating (541) and the second image light (G2) exiting from the second exit diffraction grating (542) can be reduced.

Description

Technical Field

[0001] This invention relates to a virtual image display device capable of observing virtual images, and particularly to a virtual image display device utilizing diffraction and light guiding. Background Technology

[0002] As an HMD capable of observing virtual images, it is known to have an HMD with a light guide plate on its surface formed with diffraction elements in order to make the optical system thinner (Patent Document 1). Regarding this HMD optical system, it is disclosed that the field of view of the eye alignment direction is divided using the incident coupler elements 308a-308c and the exit coupler elements 310a-310c provided on the light wave pickers 306a-306c (see [reference]). Figure 9 ,twenty two).

[0003] Patent Document 1: US Patent No. US10191288

[0004] In the HMD optical system shown in Patent Document 1, uneven brightness may occur in the region corresponding to the left side of the field of view and the region corresponding to the right side of the field of view, resulting in a large brightness difference. For example, in Figure 22 of Patent Document 1, in the exit coupler elements 310a and 310c, light incident from the incident coupler elements 308a and 308c is diffracted sequentially from the side closer to the incident coupler elements 308a and 308c to the side farther away, and then exits at an appropriate position. In the exit coupler elements 310a and 310c, the light diffracted on the side farther away from the incident coupler elements 308a and 308c has an increased diffraction number and a decreased brightness compared to the light diffracted on the side closer to the incident coupler elements 308a and 308c. Therefore, the brightness difference between the light emitted from the optical waveguide 306c corresponding to the field of view on the left side away from the incident coupler element 308c and the light emitted from the optical waveguide 306a corresponding to the field of view on the right side close to the incident coupler element 308a increases, which may result in uneven brightness. Summary of the Invention

[0005] A virtual image display device according to one aspect of the present invention includes: a first display element that emits first image light; a second display element that emits second image light; a first optical component having a first incident diffraction grating, a first exit diffraction grating, and a first pupil diffraction grating, wherein the first incident diffraction grating receives the first image light from the first display element, the first exit diffraction grating causes the incident first image light to exit toward a position forming an exit pupil, and the first pupil diffraction grating causes the first image light from the first incident diffraction grating to diffract toward the first exit diffraction grating; and a second optical component having There is a second incident diffraction grating, a second exit diffraction grating, and a second pupil diffraction grating. The second incident diffraction grating receives second image light from the second display element. The second exit diffraction grating causes the incident second image light to exit towards the position forming the exit pupil. The second pupil diffraction grating causes the second image light from the second incident diffraction grating to diffract towards the second exit diffraction grating. When viewed from the exit pupil, the first exit diffraction grating and the second exit diffraction grating overlap. The area of ​​the first exit diffraction grating from which the first image light exits is different from the area of ​​the second exit diffraction grating from which the second image light exits. Attached Figure Description

[0006] Figure 1 This is a top view illustrating the wearing state of an HMD equipped with a virtual image display device.

[0007] Figure 2 These are top and rear views of the virtual image display device according to the first embodiment.

[0008] Figure 3 These are top and rear views of the first optical device constituting the virtual image display device.

[0009] Figure 4 It is a diagram illustrating the image formation of each optical device.

[0010] Figure 5 This is a top view illustrating a modified example of a virtual image display device.

[0011] Figure 6 These are top and rear views of the virtual image display device according to the second embodiment.

[0012] Figure 7 These are top and rear views illustrating a modified example of a virtual image display device.

[0013] Figure 8 This is a diagram illustrating yet another variation of the virtual image display device.

[0014] Figure 9 This is an explanation Figure 8 A side view of a modified example of the virtual image display device shown.

[0015] Figure 10This is a top view illustrating the virtual image display device of the third embodiment.

[0016] Figure 11 This is a diagram comparing the first incident diffraction grating and the long-wavelength incident diffraction grating.

[0017] Figure 12 These are rear and side views of the virtual image display device according to the fourth embodiment.

[0018] Figure 13 These are rear and side views illustrating the structure of the first optical device.

[0019] Figure 14 These are top and rear views illustrating a modified example of a virtual image display device.

[0020] Figure 15 This is a top view illustrating a modified example of a virtual image display device.

[0021] Label Explanation

[0022] 31a, 32a, 33a First to third display elements; 31c, 32c, 33c First to third optical components; 41 display panel; 41a display surface; 42 collimating lens; 51 light guide component; 51a, 51b planes; 52a, 53a, 54a patterns; 61, 62 light shielding components; 110 virtual image display device; 111 to 113 First to third optical devices; 210 virtual image display device; 531, 532, 533 First to third dilated pupils. Gratings; 524, 525, 526 wavelength long-wavelength incident diffraction gratings; 534, 535, 536 wavelength long-wavelength pupil diffraction gratings; 544, 545, 546 wavelength long-wavelength exit diffraction gratings; DL1, DL2, DL3 display light; EP exit pupil; EY eye; G1, G2, G3 first to third image light; GB, GG, GR image light; P1, P2, P3 spacing; SE outer surface; SI light incident surface; SO light exit surface; US wearer. Detailed Implementation

[0023] [First Implementation]

[0024] The following is for reference Figure 1 The first embodiment of the virtual image display device of the present invention will be described in detail below.

[0025] Figure 1 This is a diagram illustrating the wearing state of a head-mounted display (hereinafter also referred to as HMD) 200, which allows the observer or wearer US to recognize an image as a virtual image. Figure 1In the coordinate system, X, Y, and Z are orthogonal coordinates. The +X direction corresponds to the horizontal direction of the eye EY alignment of the observer or wearer US wearing the HMD200 or virtual image display device 110. The +Y direction is equivalent to the downward direction orthogonal to the horizontal direction of the eye EY alignment for the wearer US. The +Z direction is equivalent to the frontal or forward direction for the wearer US. The ±Y directions are parallel to the vertical axis or the vertical direction.

[0026] The HMD200 includes a virtual image display device 110 for the left eye and a support device 120. The support device 120 includes a pair of temples 120a and 120b and supports the virtual image display device 110. The virtual image display device 110 is configured to cover the front of the wearer's eye EY, i.e., the +Z side.

[0027] Reference Figures 2-4 Description of the virtual image display device 110. In Figure 2 In the diagram, region AR1 is a top view of the virtual image display device 110, and region AR2 is a rear view of the virtual image display device 110. Figure 3 In the diagram, region BR1 is a top view of the first optical device 111, and region BR2 is a rear view of the first optical device 111. Figure 4 In the diagram, region CR1 describes the image formation of the first optical device 111, region CR2 describes the image formation of the second optical device 112, and region CR3 describes the image formation of the third optical device 113.

[0028] Figure 2 The virtual image display device 110 shown includes a first optical device 111, a second optical device 112, a third optical device 113, and a drive control device 91. The virtual image display device 110 has a configuration in which the first optical device 111, the second optical device 112, and the third optical device 113 are staggered in the lateral X direction and overlapped in the front-back Z direction. Here, the first optical device 111 displays a virtual image in the left-side field of view region near -X, the second optical device 112 displays a virtual image in the central field of view region relative to the left and right, and the third optical device 113 displays a virtual image in the right-side field of view region near +X. By combining the virtual image display based on the first optical device 111, the virtual image display based on the second optical device 112, and the virtual image display based on the third optical device 113, a complete image can be observed. Furthermore, since the optical devices 111 to 113 allow ambient light to pass through, the virtual image display device 110 can display a virtual image against an ambient image background. That is, the virtual image display device 110 is a perspective-type virtual image display device.

[0029] Reference Figure 3The first optical device 111 includes a first display element 31a that emits a first image light G1 and a first optical component 31c that emits the first image light G1 as display light DL1. The first display element 31a has a display panel 41 and a collimating lens 42, and the first optical component 31c has a light guide component 51, a first incident diffraction element 521, a first pupil diffraction grating 531, and a first exit diffraction grating 541. The first optical component 31c guides the first image light G1 generated by the first display element 31a to the eye EY of the wearer US, enabling the wearer US to see a virtual image.

[0030] In the first display element 31a, the display panel 41 is a display device that emits a first image light G1 to form an image corresponding to a virtual image. Specifically, it is, for example, a display of organic EL (organic electroluminescence), inorganic EL, or LED array, forming a colored static image or dynamic image on the two-dimensional display surface 41a. The display panel 41 is not limited to a self-emissive image light generating device, but can also be composed of a light modulation element such as an LCD, forming an image by illuminating the light modulation element with a light source such as a backlight. As the display panel 41, LCOS (Liquid crystal on silicon, LCoS is a registered trademark), digital micromirror devices, etc., can also be used instead of LCDs.

[0031] The collimating lens 42 is a projection optical system that includes a lens that parallelizes incident light. It parallelizes the first image light G1 from the display panel 41 to a state with a predetermined ray width and emits it toward the first optical component 31c in a state that covers a predetermined angular range corresponding to the pixel position. The first optical axis X1 of the collimating lens 42 becomes a direction that rotates counterclockwise by a predetermined angle α1 in the XZ plane relative to the +Z direction of the front surface.

[0032] In the first optical component 31c, the light guide component 51 is a component formed from parallel flat plates, having a pair of planes 51a and 51b extending parallel to the XY plane. In the upper left region of the light guide component 51, i.e., the region on the -X and -Y sides, on the outer side, i.e., the +Z side, a first incident diffraction element 521 (described later) is provided as part of or an extension of the plane 51a, i.e., the light incident surface SI. Furthermore, in the main region on the upper side (+X side), excluding the left end and its periphery of the light guide component 51, on the outer side (+Z side), a first pupil diffraction grating 531 (described later) is provided as part of the outer surface SE, which is part of the plane 51a. In the main region on the central and lower sides of the light guide component 51, excluding the left end and its periphery, i.e., the +Y side, on the opposite outer side (-Z side), a first exit diffraction grating 541 (described later) is provided as part of the light exit surface SO, which is part of the plane 51b. The pair of planes 51a and 51b in the light guide component 51 function as total internal reflection surfaces to guide the first image light G1, which is guided to the light guide component 51 via the first incident diffraction element 521, through total internal reflection. The light guide component 51 is formed, for example, from resin or glass with a thickness of about 1 to 2 mm and high light transmittance.

[0033] The first incident diffraction element 521 is disposed opposite to the collimating lens 42 in a circular region parallel to the XY plane. The first incident diffraction element 521 guides the first image light G1 emitted from the display panel 41 and passing through the collimating lens 42 into the interior of the light guide member 51. The first incident diffraction element 521 can be integrally formed with the light guide member 51, or it can be separately formed from the light guide member 51 and joined or pasted to the light incident surface SI of the light guide member 51. The first incident diffraction element 521 takes in the first image light G1 incident on it through diffraction in a manner that propagates inside the light guide member 51, specifically, for example, a surface relief diffraction grating. The first incident diffraction element 521 is formed by a pattern 52a comprising a plurality of protrusions or grooves extending linearly in the longitudinal Y direction and having a periodicity in the transverse X direction. The grating period (spacing) and grating height of the pattern 52a are constant. To enable the first image light G1 to propagate through total internal reflection in the light guide member 51, the grating period of pattern 52a is set such that the propagation angle is larger than the critical angle determined by the refractive index in the light guide member 51. Furthermore, for ease of explanation, the illustrated pattern 52a is distorted and does not reflect the actual pattern density or pattern size. Additionally, the first incident diffraction element 521 is not limited to having periodic irregularities exposed on its surface; it may also have an interface corresponding to periodic irregularities embedded within it.

[0034] The first pupil diffraction grating 531 is disposed on the +X side of the first incident diffraction element 521, bending the light path of the first image light G1, which is guided into the light guide member 51 and propagates in the +X direction, while maintaining its angular information and propagating in the +Y direction. The first pupil diffraction grating 531 can be integrally formed with the light guide member 51, or it can be separately formed from the light guide member 51 and joined or pasted to the outer surface SE of the light guide member 51. When the first image light G1 is reflected and propagated by the planes 51a and 51b of the light guide member 51, the first pupil diffraction grating 531 bends the travel direction of the first image light G1 within the light guide member 51 at a certain position through diffraction. Specifically, for example, it is a surface relief diffraction grating. The first pupil diffraction grating 531 is formed by a pattern 53a having a plurality of protrusions or grooves extending linearly in the DS1 direction parallel and inclined to the XY plane and having a periodic pattern 53a in the DS2 direction parallel to the XY plane and perpendicular to the DS1 direction. The DS1 direction is a direction rotated 45° clockwise relative to the +X direction, and is the midpoint between the +X and +Y directions. The grating period (spacing) and grating height of pattern 53a are constant. The grating periods in the X and Y directions of pattern 53a are made to match the grating period in the X direction of the first incident diffraction element 521. Furthermore, for ease of explanation, the illustrated pattern 53a is distorted and does not reflect the actual pattern density or pattern size. In addition, the first pupil grating 531 is not limited to having periodic bumps exposed on the surface; it can also have an interface equivalent to periodic bumps embedded within it.

[0035] The first exit diffraction grating 541 is disposed on the +Y side of the first pupil dilator grating 531. It extracts the first image light G1, which propagates integrally within the light guide member 51 in the +Y direction, and exits it outside the light guide member 51, directing it towards the wearer's eye EY. The first exit diffraction grating 541 can be integrally formed with the light guide member 51, or it can be separately formed and joined or adhered to the light exit surface SO of the light guide member 51. When the first image light G1 is reflected and propagated by the planes 51a and 51b of the light guide member 51, the first exit diffraction grating 541 diffracts at a certain position, causing the first image light G1 to be transmitted through diffraction and recovering the angular information before it incident on the first incident diffraction element 521. For example, the lateral exit angle β1 of the first image light G1 when it exits from the light exit surface SO is equal to the lateral incident angle α1 of the first image light G1 when it incident on the light incident surface SI. Specifically, the first exit diffraction grating 541 is, for example, a surface-embossed diffraction grating. The first exit diffraction grating 541 is formed by a pattern 54a having a plurality of protrusions or grooves extending linearly in the transverse X direction and periodicity in the longitudinal Y direction. The grating period (spacing) and grating height of the pattern 54a are constant. The grating period in the Y direction of the pattern 54a is aligned with the grating period in the X direction of the first incident diffraction element 521. Furthermore, the first exit diffraction grating 541 is not limited to having the periodic protrusions and concave surfaces exposed; an interface corresponding to the periodic protrusions and concave surfaces may also be embedded within it.

[0036] The following describes the guiding of the first image light G1 and the formation of the virtual image by the first optical device 111. The display panel 41 forms a colored static or dynamic image on a two-dimensional display surface 41a. The first image light G1 from the display surface 41a is collimated by the collimating lens 42, thereby, when viewed from above in the +Y direction, incident at an angle corresponding to the position in the X direction of the display surface 41a onto the first incident diffraction element 521, diffracted in an angle direction corresponding to the spacing of the pattern 52a formed on the first incident diffraction element 521, totally internally reflected and propagated in the light guide member 51, advancing as a whole in the +X direction. In the light guide member 51, the first image light G1, propagating as a whole in the +X direction, is diffracted by the first pupil grating 531 and bent in the +Y direction, shifting the light path as a whole to a position in the +X direction reflecting the number of reflections up to being diffracted by the first pupil grating 531. That is, the first pupil dilatation grating 531 has the function of magnifying the lateral pupil size, which is equivalent to the width of the light rays in the lateral or X direction that the first image light G1 is incident on the eye EY. The first image light G1, which propagates as a whole in the light guide member 51 in the +Y direction after passing through the first pupil dilatation grating 531, is diffracted by the first exit diffraction grating 541 and exits from the light exiting surface SO toward the eye EY. The first image light G1, i.e., the display light DL1, exiting from the light exiting surface SO, maintains the angular state of its exit from the display surface 41a in the +X and +Y directions, and the pupil size is enlarged in the +X direction. That is, the first image light G1 enlarges the pupil size in the longitudinal and lateral directions via the first optical member 31c, so that even if the position of the eye EY is significantly shifted in the longitudinal and lateral directions, the virtual image formed by the first image light G1 from the first display element 31a can be observed.

[0037] The shaded area RH of the dot pattern is the area where the virtual image within the field of view range handled by the first optical device 111 can be seen simultaneously. Therefore, by placing the eye EY in this area, as described later, the virtual image with a lateral field of view from -30° to -10° can be observed without deficiency.

[0038] Return to Figure 2The second optical device 112 includes a second display element 32a that emits a second image light G2 and a second optical component 32c that emits the second image light G2 as display light DL2. The second display element 32a has a display panel 41 and a collimating lens 42, and the second optical component 32c has a light guide component 51, a second incident diffraction element 522, a second pupil grating 532, and a second exit diffraction grating 542. The second display element 32a has the same structure as the first display element 31a, but the second optical axis X2 of the second display element 32a is tilted relative to the first optical axis X1 of the first display element 31a, specifically, it is parallel to the Z direction of the front surface. As a result, the incident angle α2 of the second image light G2 incident on the second incident diffraction grating 522 is different from the incident angle α1 of the first image light G1 incident on the first incident diffraction grating 521. With clockwise rotation set to positive, the incident angle α2 of the second image light G2 is greater than the incident angle α1 of the first image light G1. The second optical component 32c has the same structure as the first optical component 31c, and the relative arrangement of the second incident diffraction element 522, the second pupil grating 532, and the second exit diffraction grating 542 is approximately the same as the relative arrangement of the first incident diffraction element 521, the first pupil grating 531, and the first exit diffraction grating 541 of the first optical component 31c. However, due to the relationship with the incident angle α2, in order to easily satisfy the condition of total internal reflection, the spacing of patterns 52a, 53a, and 54a on the second incident diffraction element 522, the second pupil grating 532, and the second exit diffraction grating 542 is smaller than the spacing of patterns 52a, 53a, and 54a on the first incident diffraction element 521, the first pupil grating 531, and the first exit diffraction grating 541 of the first optical component 31c.

[0039] like Figure 4 As shown, the spacing P2 of the second incident diffraction element 522 in the second optical component 32c is set to be smaller than the spacing P1 of the first incident diffraction element 521 in the first optical component 31c. As a result, the angle at which the first image light G1 is diffracted by the first incident diffraction grating 521 is smaller than the angle at which the second image light G2 is diffracted by the second incident diffraction grating 522.

[0040] Return to Figure 2The third optical device 113 includes a third display element 33a that emits a third image light G3 and a third optical component 33c that emits the third image light G3 as display light DL3. The third display element 33a has a display panel 41 and a collimating lens 42, and the third optical component 33c has a light guide component 51, a third incident diffraction element 523, a third pupil grating 533, and a third exit diffraction grating 543. The third display element 33a has the same structure as the first display element 31a, but the third optical axis X3 of the third display element 33a is tilted relative to the first optical axis X1 of the first display element 31a and the second optical axis X2 of the second display element 32a. Specifically, it is tilted clockwise by a predetermined angle α3 relative to the +Z direction of the front surface. As a result, the incident angle α3 of the third image light G3 incident on the third incident diffraction grating 523 is different from the incident angle α2 of the second image light G2 incident on the second incident diffraction grating 522. Assuming clockwise is positive, the incident angle α3 of the third image light G3 is greater than the incident angle α2 of the second image light G2. The third optical component 33c has the same structure as the first optical component 31c or the second optical component 32c, and the relative arrangement of the third incident diffraction element 523, the third pupil grating 533, and the third exit diffraction grating 543 is approximately consistent with the relative arrangement of the first incident diffraction element 521, the first pupil grating 531, and the first exit diffraction grating 541 of the first optical component 31c. However, due to the relationship with the incident angle, in order to easily meet the condition of total internal reflection, the spacing of patterns 52a, 53a, and 54a on the third incident diffraction element 523, the third pupil grating 533, and the third exit diffraction grating 543 is smaller than the spacing of patterns 52a, 53a, and 54a on the second incident diffraction element 522, the second pupil grating 532, and the second exit diffraction grating 542 of the second optical component 32c.

[0041] like Figure 4 As shown, the spacing P3 of the third incident diffraction element 523 of the third optical component 33c is set to be smaller than the spacing P2 of the second incident diffraction element 522 of the second optical component 32c. As a result, the angle at which the second image light G2 is diffracted by the second incident diffraction grating 522 is smaller than the angle at which the third image G3 is diffracted by the third incident diffraction grating 523.

[0042] The spacings P1, P2, and P3 of the first incident diffraction element 521, the second incident diffraction element 522, and the third incident diffraction element 523 satisfy the following relationship:

[0043] P1>P2>P3.

[0044] Return to Figure 2The second optical component 32c is configured to be offset towards the +X side compared to the first optical component 31c, and the third optical component 33c is configured to be offset towards the +X side compared to the second optical component 32c. Image lights G1, G2, and G3 from the optical components 31c, 32c, and 33c are incident in a manner that overlaps at the exit pupil EP where the eye EY should be positioned. At this time, the second incident diffraction element 522 of the second optical component 32c is positioned towards the +X side compared to the first incident diffraction element 521 of the first optical component 31c, and the second pupil dilator grating 532 is positioned towards the +X side compared to the first pupil dilator grating 531. The second incident diffraction element 522 is disposed on the second optical component 32c such that it partially overlaps with the first pupil dilator grating 531 when viewed from the exit pupil EP. The second pupil dilator grating 532 is disposed on the second optical component 32c such that it partially overlaps with the third pupil dilator grating 533 when viewed from the exit pupil EP. The third incident diffraction element 523 of the third optical component 33c is positioned on the +X side closer to the second incident diffraction element 522 of the second optical component 32c. The third pupil dilator grating 533 is positioned on the +X side closer to the second pupil dilator grating 532. The third incident diffraction element 523 is disposed on the third optical component 33c such that it overlaps with the second pupil dilator grating 532 when viewed from the exit pupil EP. The third pupil dilator grating 533 is disposed on the third optical component 33c such that it partially overlaps with the second pupil dilator grating 532 when viewed from the exit pupil EP.

[0045] When viewed from the exit pupil EP, the first exit diffraction grating 541 overlaps with the second exit diffraction grating 542, and the second exit diffraction grating 542 overlaps with the third exit diffraction grating 543. As a result, the second exit diffraction grating 542 causes the second image light G2 to pass through the first exit diffraction grating 541 and exit towards the position forming the exit pupil EP. Furthermore, the third exit diffraction grating 543 causes the third image light G3 to pass through the second exit diffraction grating 542 and exit towards the position forming the exit pupil EP. Based on observation from the eye (EY), the display areas EA1 of the first image light G1 emitted by the first outgoing diffraction grating 541, EA2 of the second image light G2 emitted by the second outgoing diffraction grating 542, and EA3 of the third image light G3 emitted by the third outgoing diffraction grating 543 are different in the horizontal direction, but partially overlap.

[0046] In the first optical device 111, a first incident diffraction grating 521 and a first pupil diffraction grating 531 are disposed on a plane 51a, which is the +Z side, on one side of the first optical component 31c or light guide component 51, and a first exit diffraction grating 541 is disposed on a plane 51b, which is the -Z side, on the other side of the first optical component 31c or light guide component 51. This allows the first display element 31a to be positioned on the outside, ensuring sufficient space between the first optical component 31c and the exit pupil EP. Similarly, in the second optical device 112, a second incident diffraction grating 522 and a second pupil diffraction grating 532 are disposed on a plane 51a, which is one side of the second optical component 32c, and a second exit diffraction grating 542 is disposed on a plane 51b, which is the other side of the second optical component 32c. In the third optical device 113, the third incident diffraction grating 523 and the third pupil diffraction grating 533 are disposed on a plane 51a on one side of the third optical component 33c, and the third exit diffraction grating 543 is disposed on a plane 51b on the other side of the third optical component 33c.

[0047] Reference Figure 4 The angle range θ1 of the first image light G1 incident from the first display element 31a to the first optical component 31c in the XZ plane is 0° in the Z direction, for example, within the range of -30° to -10°, and is an angle difference of 20°. The angle range θ2 of the second image light G2 incident from the second display element 32a to the second optical component 32c in the XZ plane is 0° in the Z direction, for example, within the range of -10° to +10°, and is an angle difference of 20°. The angle range θ3 of the third image light G3 incident from the third display element 33a to the third optical component 33c in the XZ plane is 0° in the Z direction, for example, within the range of +10° to +30°, and is an angle difference of 20°. As a result, the field of view θ11 of the first image light G1 emitted from the first optical component 31c in the XZ plane is equal to the angle range θ1, which is -30° to -10°. The field of view θ21 of the second image light G2 emitted from the second optical component 32c in the XZ plane is equal to the angle range θ2, which is -10° to +10°. The field of view θ31 of the third image light G3 emitted from the third optical component 33c in the XZ plane is equal to the angle range θ3, which is +10° to +30°. Thus, a virtual image continuously covering a field of view of -30° to +30° is provided to the eye EY. To achieve the above continuous field of view, in the first display element 31a, the tilt of the first optical axis X1 is set to counterclockwise α1 = -20°, and in the third display element 33a, the tilt of the third optical axis X3 is set to counterclockwise α3 = +20°.

[0048] Figure 5This is a top view illustrating a modified example of the virtual image display device 110. In this case, in the second optical component 32c of the second optical device 112, a light-shielding component 61 is disposed on the opposite side of the light guide component 51 sandwiched between the second incident diffraction element 522 and the light guide component 51. The light-shielding component 61 is positioned opposite the plane 51b of the light guide component 51 when separated from it. This light-shielding component 61 is used to prevent the second image light G2 transmitted through the second incident diffraction element 522 from entering the light guide component 51 of the adjacent first optical component 31c, and to absorb or block the second image light G2 transmitted through the second incident diffraction element 522. By distributing the light-shielding component 61 separately from the light guide component 51, the complete absorption of the second image light G2 that enters the light guide component 51 through the second incident diffraction element 522 is prevented. In the third optical component 33c of the third optical device 113, a light-shielding component 61 is also disposed separately from the light-guide component 51 on the opposite side of the light-guide component 51 sandwiched between the third incident diffraction element 523 and the light-guide component 51. This light-shielding component 61 prevents the third image light G3 transmitted through the third incident diffraction element 523 from entering the light-guide component 51 of the second optical component 32c.

[0049] The light-shielding component 61 can be fixed in a part of the light guide component 51 that does not affect the optical path, or it can be fixed to the support device 120 by a fixing component not shown. Figure 1 ).

[0050] In the virtual image display device 110 of the first embodiment described above, there are a first optical component 31c and a second optical component 32c. The first optical component 31c includes: a first display element 31a that emits a first image light G1; a second display element 32a that emits a second image light G2; a first incident diffraction grating 521 that receives the first image light G1 from the first display element 31a; a first exit diffraction grating 541 that causes the received first image light G1 to exit towards a position forming an exit pupil EP; and a first pupil diffraction grating 531 that causes the first image light G1 from the first incident diffraction grating 521 to diffract towards the first exit diffraction grating 541. The optical component 32c includes: a second incident diffraction grating 522 that receives the second image light G2 from the second display element 32a; a second exit diffraction grating 542 that causes the incident second image light G2 to exit at a position forming an exit pupil EP; and a second pupil diffraction grating 532 that causes the second image light G2 from the second incident diffraction grating 522 to diffract the second exit diffraction grating 542. When viewed from the exit pupil EP, the first exit diffraction grating 541 and the second exit diffraction grating 542 overlap, and the area of ​​the first exit diffraction grating 541 that receives the first image light G1 is different from the area of ​​the second exit diffraction grating 542 that receives the second image light G2.

[0051] In the aforementioned virtual image display device, when viewed from the exit pupil EP, the first exit diffraction grating 541 and the second exit diffraction grating 542 overlap. The area from which the first image light G1 is emitted by the first exit diffraction grating 541 is different from the area from which the second image light G2 is emitted by the second exit diffraction grating 542. Therefore, it is possible to avoid a large difference between the light path from the first display element 31a to the first exit diffraction grating 541 and the light path from the second display element 32a to the second exit diffraction grating 542. This reduces the brightness unevenness in the displayed virtual image caused by the increased brightness difference between the first image light G1 emitted from the first exit diffraction grating 541 and the second image light G2 emitted from the second exit diffraction grating 542.

[0052] [Second Implementation]

[0053] Hereinafter, a virtual image display device according to the second embodiment of the present invention will be described. Furthermore, the virtual image display device of the second embodiment partially modifies the virtual image display device of the first embodiment; descriptions of common parts are omitted.

[0054] Reference Figure 6 The virtual image display device 110 according to the second embodiment will be described. Figure 6 In the diagram, region CR1 is a top view of the virtual image display device 110, and region CR2 is a rear view of the virtual image display device 110. At this time, the first optical device 111, the second optical device 112, and the third optical device 113 have approximately equal dimensions in the longitudinal and transverse directions, based on the XY plane, and overlap in the Z direction. However, in order not to obstruct the arrangement of the first display element 31a and the second display element 32a, notches 51c are provided at the corners of the light guide members 51 of the first optical component 31c and the second optical component 32c.

[0055] In this configuration, the first optical component 31c, the second optical component 32c, and the third optical component 33c overlap to the same size and extend in a manner that covers the field of vision. Therefore, the end of the light guide component 51 is not easily visible, and the optical structure of the optical components 31c, 32c, and 33c is not easily visible to the wearer US. Furthermore, if the configuration of the first display element 31a and the second display element 32a is considered, the notch 51c is not necessary.

[0056] exist Figure 6 In the example, the relative position of the first pupil grating 531 in the first optical component 31c partially overlaps with, but is different from, the relative position of the second pupil grating 532 in the second optical component 32c, and also partially overlaps with, but is different from, the relative position of the third pupil grating 533 in the third optical component 33c.

[0057] Figure 7This is a diagram illustrating a modified example of the virtual image display device 110. Figure 7 In the diagram, region DR1 is a top view of the virtual image display device 110, and region DR2 is a rear view of the virtual image display device 110. In this case, in the second optical component 32c of the second optical device 112, the second exit diffraction grating 542 has a longitudinal and transverse extension that completely covers the third exit diffraction grating 543 of the third optical component 33c of the third optical device 113. Furthermore, in the first optical component 31c of the first optical device 111, the first exit diffraction grating 541 has a longitudinal and transverse extension that completely covers the second exit diffraction grating 542 of the second optical component 32c of the second optical device 112. That is, the second exit diffraction grating 542 and the first exit diffraction grating 541 extend beyond the area required for imaging. Particularly in the illustrated example, the ±X or ±Y edges of the second exit diffraction grating 542 and the third exit diffraction grating 543 coincide with the edge of the first exit diffraction grating 541. In this situation, the wearer US will not only have difficulty seeing the first exit diffraction grating 541, but also the edges of the second exit diffraction grating 542 and the third exit diffraction grating 543.

[0058] Figure 8 This is a diagram illustrating yet another variation of the virtual image display device 210. Figure 8 In the diagram, region ER1 is a front view of the virtual image display device 210, and region ER2 is a top view of the virtual image display device 210. The virtual image display device 210 is for both eyes, and includes a virtual image display device 110A for the left eye and a virtual image display device 110B for the right eye. Furthermore, each virtual image display device 110A, 110B and... Figure 6 The virtual image display device 110 shown is the same, but it can also be the same as... Figure 7 The virtual image display device 110 shown is the same.

[0059] Figure 9 This is an explanation Figure 8 This is a side view of a modified example of the virtual image display device 210. In this case, a light-shielding member 62 is disposed separately from the light guide member 51 on the inner side of the virtual image display devices 110A and 110B, opposite to the pupil gratings 531, 532, 533, etc. This light-shielding member 62 prevents the display elements 31a, 32a, 33a from being disposed in an observable state within the field of view, and prevents the pupil gratings 531, 532, 533 from being disposed in an observable state within the field of view.

[0060] [Third Implementation]

[0061] Hereinafter, a virtual image display device according to the third embodiment of the present invention will be described. Furthermore, the virtual image display device of the third embodiment partially modifies the virtual image display device of the first embodiment; descriptions of common parts are omitted.

[0062] Figure 10 This is a top view illustrating the virtual image display device 110 according to the third embodiment. The first optical device 111 includes a fourth optical element 34c as an optical element for the second band, the second optical device 112 includes a fifth optical element 35c as an optical element for the second band, and the third optical device 113 includes a sixth optical element 36c as an optical element for the second band. The fourth optical element 34c is sandwiched between the first optical element 31c and the second optical element 32c, the fifth optical element 35c is sandwiched between the second optical element 32c and the third optical element 33c, and the sixth optical element 36c is disposed opposite to the third optical element 33c on the outer side.

[0063] The first display element 31a forms the image light GB in the blue area, the image light GG in the green area, and the image light GR in the red area. The second display element 32a and the third display element 33a also form the image light GB in the blue area, the image light GG in the green area, and the image light GR in the red area.

[0064] The first optical component 31c, the second optical component 32c, and the third optical component 33c efficiently propagate image light GB and GG, which are the blue and green regions of the first band. The fourth optical component 34c, the fifth optical component 35c, and the sixth optical component 36c efficiently propagate image light GR, which is the red region of the second band.

[0065] The fourth optical component 34c covers the left field of view in the same way as the first optical component 31c. The fourth optical component 34c includes: a long-wavelength incident diffraction grating 524 for diffracting the image light GR, which is in the red region of the second band; a long-wavelength exit diffraction grating 544 for diffracting the incident image light GR toward the position forming the exit pupil EP; and a long-wavelength pupil diffraction grating 534 for diffracting the image light GR from the long-wavelength incident diffraction grating 524 toward the long-wavelength exit diffraction grating 544. The image light GR incident on the long-wavelength incident diffraction grating 524 of the fourth optical component 34c is coupled to its attached light guide component 51, and the image lights GB and GG, which pass through the blue and green regions of the long-wavelength incident diffraction grating 524, are coupled to the light guide component 51 through the first incident diffraction grating 521 disposed in the next first optical component 31c.

[0066] The fifth optical component 35c covers the central field of view in the same way as the second optical component 32c. The fifth optical component 35c includes: a long-wavelength incident diffraction grating 525 for diffracting image light GR, which is in the red region of the second band; a long-wavelength exit diffraction grating 545 for causing the incident image light GR to exit towards the position forming the exit pupil EP; and a long-wavelength pupil diffraction grating 535 for causing the image light GR from the long-wavelength incident diffraction grating 525 to diffract towards the long-wavelength exit diffraction grating 545. The image light GR incident on the long-wavelength incident diffraction grating 525 of the fifth optical component 35c is coupled to the light guide component 51 therewith, and the image light GB and GG in the blue and green regions of the long-wavelength incident diffraction grating 525 are coupled to the light guide component 51 through the second incident diffraction grating 522 disposed in the next second optical component 32c.

[0067] The sixth optical component 36c, like the third optical component 33c, covers the right field of view. The sixth optical component 36c includes: a long-wavelength incident diffraction grating 526 that diffracts the image light GR, which is in the red region of the second band; a long-wavelength exit diffraction grating 546 that directs the incident image light GR towards a position forming the exit pupil EP; and a long-wavelength pupil diffraction grating 536 that diffracts the image light GR from the long-wavelength incident diffraction grating 526 towards the long-wavelength exit diffraction grating 546. The long-wavelength image light GR incident on the sixth optical component 36c is coupled to its associated light guide component 51. Image lights GB and GG, which pass through the blue and green regions of the long-wavelength incident diffraction grating 526, are coupled to the light guide component 51 via a third incident diffraction grating 523 disposed on the next third optical component 33c.

[0068] Figure 11 This is a partially enlarged cross-sectional view comparing the structures of the first incident diffraction grating 521 and the long-wavelength incident diffraction grating 524. The spacing PR of the long-wavelength incident diffraction grating 524 is greater than the spacing PGB of the first incident diffraction grating 521. Furthermore, the grating height HR of the long-wavelength incident diffraction grating 524 is greater than the grating height HGB of the first incident diffraction grating 521. While the first incident diffraction grating 521 and the long-wavelength incident diffraction grating 524 have been compared above, when comparing the second incident diffraction grating 522 and the long-wavelength incident diffraction grating 525, the spacing and grating height of the long-wavelength incident diffraction grating 525 are relatively larger than those of the second incident diffraction grating 522. Furthermore, when comparing the third incident diffraction grating 523 and the long-wavelength incident diffraction grating 526, the spacing and grating height of the long-wavelength incident diffraction grating 526 are relatively larger than those of the third incident diffraction grating 523.

[0069] The image light GR is coupled to the light guide component 51 via a long-wavelength incident diffraction grating 524. Alternatively, the image light GR and GG from the red and green regions can also be coupled to the light guide component 51 via the long-wavelength incident diffraction grating 524, while the image light GB from the blue region can be coupled to the light guide component 51 via the first incident diffraction grating 521. In this case, long-wavelength incident diffraction gratings 525 and 526 are also used for the image light GR and GG from the red and green regions.

[0070] [Fourth Implementation]

[0071] Hereinafter, a virtual image display device according to the fourth embodiment of the present invention will be described. Furthermore, the virtual image display device of the fourth embodiment partially modifies the virtual image display device of the first embodiment; descriptions of common parts are omitted.

[0072] Reference Figure 12 The virtual image display device 110 according to the fourth embodiment will be described. Figure 12 In the diagram, region FR1 is a rear view of the virtual image display device 110, and region FR2 is a side view of the virtual image display device 110.

[0073] The first optical device 111 includes a fourth display element 37a, equivalent to the third display element in the claim, as an additional element to the first display element 31a. The fourth display element 37a emits a fourth image light G4, equivalent to the third image light in the claim. Furthermore, in the first optical component 31c, in addition to the light guide component 51, the first incident diffraction element 521, the first pupil grating 531, and the first exit diffraction grating 541, the first optical device 111 also includes, as additional elements: a fourth incident diffraction grating 527, equivalent to the third incident diffraction grating in the claim, which receives the fourth image light G4 from the fourth display element 37a, which is the third display element; and a fourth pupil grating 537, equivalent to the third pupil grating in the claim, which diffracts the fourth image light G4 from the fourth incident diffraction grating 527 toward the first exit diffraction grating 541.

[0074] The second optical device 112 includes a fifth display element 38a, equivalent to the fourth display element in the claim, as an additional element to the second display element 32a. The fifth display element 38a emits a fifth image light G5, equivalent to the fourth image light in the claim. Furthermore, in the second optical component 32c, in addition to the light guide component 51, the second incident diffraction element 522, the second pupil grating 532, and the second exit diffraction grating 542, the second optical device 112 also includes, as additional elements: a fifth incident diffraction grating 528, equivalent to the fourth incident diffraction grating in the claim, which receives the fifth image light G5 from the fifth display element 38a, which is the fourth display element; and a fifth pupil grating 538, equivalent to the fourth pupil grating in the claim, which diffracts the fifth image light G5 from the fifth incident diffraction grating 528 toward the second exit diffraction grating 542.

[0075] The third optical device 113 includes a sixth display element 39a that emits the sixth image light G6 as an additional element to the third display element 33a. Furthermore, in the third optical component 33c, in addition to the light guide component 51, the third incident diffraction element 523, the third pupil grating 533, and the third exit diffraction grating 543, the third optical device 113 also includes, as additional elements: a sixth incident diffraction grating 529, which receives the sixth image light G6 from the sixth display element 39a; and a sixth pupil grating 539, which diffracts the sixth image light G6 from the sixth incident diffraction grating 529 toward the third exit diffraction grating 543.

[0076] Figure 13 This is a diagram illustrating the structure of the first optical device 111. Figure 13 In the diagram, region GR1 is a rear view of the first optical device 111, and region GR2 is a side view of the first optical device 111. In this case, by also dividing the field of view in the vertical direction (Y direction) of the image into two parts (e.g., dividing it into two parts), a virtual image with a large field of view is displayed as a whole in both the vertical and horizontal directions.

[0077] In this case, the two image projection components, namely the first display element 31a and the fourth display element 37a, share the longitudinal image formation. The first display element 31a is responsible for the field of view angle of 0° to +20° in the Y direction, and the fourth display element 37a is responsible for the field of view angle of -20° to 0° in the Y direction. In order to couple the first image light G1 and the fourth image light G4 to the light guide component 51 of the first optical component 31c, the first display element 31a and the fourth display element 37a are tilted in the Y direction by +10° and -10° respectively relative to the normals of the first incident diffraction element 521 and the fourth incident diffraction element 527. The field of view of the image light emitted from the first exit diffraction grating 541 is from 0° to +20° (represented by the solid line in the figure) and from -20° to 0° (represented by the dashed line in the figure), and is vertically symmetrical in the Y direction. This allows the spacing required for diffraction to be consistent, thus enabling the first exit diffraction grating 541 to be common. Furthermore, the spacing of the diffraction gratings of the first incident diffraction element 521 is consistent with the spacing of the diffraction gratings of the fourth incident diffraction grating 527. Additionally, the spacing of the diffraction gratings of the second incident diffraction element 522 is consistent with the spacing of the diffraction gratings of the fifth incident diffraction grating 528. The spacing of the diffraction gratings of the third incident diffraction element 523 is also consistent with the spacing of the diffraction gratings of the sixth incident diffraction grating 529.

[0078] The shaded area RH of the dot pattern is the region where the virtual image, divided into vertically and horizontally, can be seen simultaneously. Therefore, by placing the eye EY in this region, a virtual image with a 40° field of view can be observed without any defects in the longitudinal Y direction. In this case, the light guide component 51 only needs to propagate a 20° field of view, but as a whole, a virtual image with a 40° field of view can be seen in the Y direction. That is, the field of view propagated by the light guide component 51 is small, thus reducing brightness and color unevenness of the virtual image.

[0079] Figure 14 This is a diagram illustrating a modified example of the virtual image display device 110. Figure 14 In the diagram, region HR1 is a top view of the first optical device 111, and region HR2 is a rear view of the first optical device 111. In this case, the arrangement... Figure 13 The virtual image display device 110 shown is divided into three sections in the vertical direction and two sections in the horizontal direction.

[0080] Figure 15 This is a diagram illustrating yet another modified example of the virtual image display device 110, and... Figure 12Correspondingly, in this case, in the second optical component 32c of the second optical device 112, a light-shielding component 61 is disposed on the side opposite to the first optical device 111, which is the side opposite to the second incident diffraction element 522 that sandwiches the light guide component 51. Additionally, a light-shielding component 61 is disposed on the side opposite to the fifth incident diffraction element 528 that sandwiches the light guide component 51, which is the side opposite to the first optical device 111. The light-shielding component 61 prevents light from leaking between the light guide components 51.

[0081] Furthermore, in the third optical component 33c of the third optical device 113, a light-shielding component 61 is disposed on the side opposite to the third incident diffraction element 523 that sandwiches the light guide component 51, i.e., the side of the second optical device 112. Additionally, a light-shielding component 61 is disposed on the side opposite to the sixth incident diffraction element 529 that sandwiches the light guide component 51, i.e., the side of the second optical device 112. The light-shielding component 61 prevents light from leaking between the light guide components 51.

[0082] [Other matters]

[0083] The above description is an example; various modifications can be made within the scope of achieving the same function.

[0084] The DS1 direction of the pattern tilt of the first pupil grating 53 is a direction rotated 45° clockwise relative to the +X direction, but the DS1 direction is not limited to a direction rotated 45° clockwise relative to the +X direction.

[0085] The first incident diffraction grating 521 and the first pupil diffraction grating 531 are arranged on one side of the light guide component 51, i.e., the +Z side, and the first exit diffraction grating 541 is arranged on the other side of the light guide component 51, i.e., the -Z side. However, the configuration of these light guide components 51 can also be interchanged in the ±Z direction.

[0086] The virtual image display device 100 and the like can be used as an HMD, but are not limited thereto. The invention can be applied to various optical devices, such as head-up displays (HUDs).

[0087] Furthermore, while the above describes a perspective-type virtual image display device that overlays external images (real objects) and virtual images, it is not limited to this and can be used for so-called closed-type devices for observing virtual reality.

[0088] A virtual image display device of a specific manner includes: a first display element that emits first image light; a second display element that emits second image light; a first optical component having a first incident diffraction grating, a first exit diffraction grating, and a first pupil diffraction grating, wherein the first incident diffraction grating receives the first image light from the first display element, the first exit diffraction grating causes the incident first image light to exit toward a position forming an exit pupil, and the first pupil diffraction grating causes the first image light from the first incident diffraction grating to diffract toward the first exit diffraction grating; and a second optical component having a first incident diffraction grating, a first exit diffraction grating, and a second exit diffraction grating. The system comprises two incident diffraction gratings, a second exit diffraction grating, and a second pupil diffraction grating. The second incident diffraction grating receives second image light from a second display element. The second exit diffraction grating causes the incident second image light to exit towards the location forming the exit pupil. The second pupil diffraction grating causes the second image light from the second incident diffraction grating to diffract towards the second exit diffraction grating. When viewed from the exit pupil, the first exit diffraction grating overlaps with the second exit diffraction grating. The area of ​​the first exit diffraction grating from which the first image light exits is different from the area of ​​the second exit diffraction grating from which the second image light exits.

[0089] In the aforementioned virtual image display device, when viewed from the exit pupil, the first exit diffraction grating and the second exit diffraction grating overlap. The area of ​​the first exit diffraction grating from which the first image light is emitted is different from the area of ​​the second exit diffraction grating from which the second image light is emitted. Therefore, it is possible to avoid a large difference between the optical path from the first display element to the first exit diffraction grating and the optical path from the second display element to the second exit diffraction grating. This reduces the brightness unevenness in the displayed virtual image caused by the increased brightness difference between the first image light emitted from the first exit diffraction grating and the second image light emitted from the second exit diffraction grating.

[0090] Specifically, the angle of incidence of the first image light incident on the first incident diffraction grating is different from the angle of incidence of the second image light incident on the second incident diffraction grating. Therefore, the angle of incidence covered by the first incident diffraction grating is different from that covered by the second incident diffraction grating, and their respective field-of-view ranges are also different.

[0091] In a specific aspect, the second exit diffraction grating causes the second image light to exit through the first exit diffraction grating toward the position forming the exit pupil.

[0092] In a specific aspect, the second incident diffraction grating is disposed on the second optical component in such a manner that it overlaps with the first diffraction grating when viewed from the exit pupil.

[0093] Specifically, a first light-shielding member is provided between the second incident diffraction grating and the first pupil grating to block the second image light. In this case, light crossing between the first optical member and the second optical member can be prevented, and the generation of stray light can be suppressed.

[0094] In a specific aspect, the relative position of the first pupil grating in the first optical component is different from the relative position of the second pupil grating in the second optical component.

[0095] Specifically, the spacing between the gratings of the first incident diffraction grating is larger than the spacing between the gratings of the second incident diffraction grating, and the angle at which the first image light is diffracted by the first incident diffraction grating is smaller than the angle at which the second image light is diffracted by the second incident diffraction grating. In this case, the propagation angle for guiding light to the first optical component and the propagation angle for guiding light to the second optical component can be made close, resulting in efficient light guiding, pupil expansion, and light extraction.

[0096] In a specific aspect, the first optical component is provided with a first incident diffraction grating and a first pupil diffraction grating on one side, and a first exit diffraction grating on the other side, which is the opposite side to one side.

[0097] Specifically, the first incident diffraction grating diffracts the image light containing the first wavelength band in the first image light. The virtual image display device includes an optical component for the second wavelength band. This second wavelength band optical component includes a long-wavelength incident diffraction grating, a long-wavelength exit diffraction grating, and a long-wavelength pupil diffraction grating. The long-wavelength incident diffraction grating diffracts the image light containing the second wavelength band in the first image light, which is on the wavelength side longer than the first wavelength band. The long-wavelength exit diffraction grating directs the incident image light containing the second wavelength band to exit towards the position forming the exit pupil. The long-wavelength pupil diffraction grating diffracts the image light containing the second wavelength band from the long-wavelength incident diffraction grating towards the long-wavelength exit diffraction grating. In this case, when displaying multiple colors, the diffraction angle and diffraction efficiency can be set to an optimal state for each color, suppressing the generation of color unevenness.

[0098] In a specific aspect, the height of the first incident diffraction grating is lower than that of the incident diffraction grating for longer wavelengths. In this case, the first incident diffraction grating is suitable for diffraction at shorter wavelengths, which can improve light utilization efficiency.

[0099] In a specific aspect, the second-band optical component is positioned between the first and second optical components. In this case, the first and second-band optical components are arranged close together, which easily suppresses the generation of color unevenness.

[0100] In a specific aspect, the virtual image display device further includes: a third display element that emits a third image light; and a fourth display element that emits a fourth image light; a first optical component having a third incident diffraction grating and a third pupil grating, the third incident diffraction grating receiving the third image light from the third display element, and the third pupil grating causing the third image light from the third incident diffraction grating to diffract towards the first exit diffraction grating; a second optical component having a fourth incident diffraction grating and a fourth pupil grating, the fourth incident diffraction grating receiving the fourth image light from the fourth display element, and the fourth pupil grating causing the fourth image light from the fourth incident diffraction grating to diffract towards the second exit diffraction grating. In this case, the third image light, which is incident on the first exit diffraction grating via the third incident diffraction grating and the third pupil diffraction grating, and the first image light, which is incident on the first exit diffraction grating via the first incident diffraction grating and the first pupil diffraction grating, mutually compensate for the field of view. The fourth image light, which is incident on the second exit diffraction grating via the fourth incident diffraction grating and the fourth pupil diffraction grating, and the second image light, which is incident on the second exit diffraction grating via the second incident diffraction grating and the second pupil diffraction grating, mutually compensate for the field of view. Therefore, in the direction in which the first and third incident diffraction gratings are arranged, the range of diffraction angles equally borne by the two incident diffraction gratings can be narrowed, and in the direction in which the second and fourth incident diffraction gratings are arranged, the range of diffraction angles equally borne by the two incident diffraction gratings can be narrowed, thus more reliably suppressing the generation of brightness difference in the virtual image.

[0101] Specifically, the fourth incident diffraction grating is disposed on the second optical component in such a manner that it overlaps with the third diffraction grating when viewed from the exit pupil, and a second light-shielding component is provided between the fourth incident diffraction grating and the third diffraction grating to block the fourth image light. In this case, light crossing between the first and second optical components can be prevented, and the generation of stray light can be suppressed.

[0102] Specifically, the spacing of the first incident diffraction grating is the same as that of the third incident diffraction grating, and the spacing of the second incident diffraction grating is the same as that of the fourth incident diffraction grating. At this time, the first and third image lights with consistent diffraction conditions are guided to the first exit diffraction grating, and the second and fourth image lights with consistent diffraction conditions are guided to the second exit diffraction grating.

Claims

1. An image display device of a virtual image type, comprising: a first display element which emits first image light; a second display element which emits second image light; a first optical member which has a first incident diffraction grating, a first exit diffraction grating, and a first pupil expanding grating, the first incident diffraction grating which is incident with the first image light from the first display element, the first exit diffraction grating which emits the incident first image light toward a position at which an exit pupil is formed, and the first pupil expanding grating which diffracts the first image light from the first incident diffraction grating toward the first exit diffraction grating; and a second optical member which has a second incident diffraction grating, a second exit diffraction grating, and a second pupil expanding grating, the second incident diffraction grating which is incident with the second image light from the second display element, the second exit diffraction grating which emits the incident second image light toward the position at which the exit pupil is formed, and the second pupil expanding grating which diffracts the second image light from the second incident diffraction grating toward the second exit diffraction grating, wherein the first exit diffraction grating and the second exit diffraction grating overlap each other when viewed from the exit pupil, a region of the first exit diffraction grating from which the first image light is emitted is different from a region of the second exit diffraction grating from which the second image light is emitted, the first pupil expanding grating is disposed on one side of the first optical member in a manner so as to overlap the first exit diffraction grating when viewed from the exit pupil, and the second pupil expanding grating is disposed on one side of the second optical member in a manner so as to overlap the second exit diffraction grating when viewed from the exit pupil.

2. The image display device according to claim 1, wherein an incident angle of the first image light incident on the first incident diffraction grating is different from an incident angle of the second image light incident on the second incident diffraction grating.

3. The image display device according to claim 1 or 2, wherein the second exit diffraction grating emits the second image light toward the position at which the exit pupil is formed through the first exit diffraction grating.

4. The image display device according to claim 1 or 2, wherein the second incident diffraction grating is disposed in the second optical member in a manner so as to overlap the first pupil expanding grating when viewed from the exit pupil.

5. The image display device according to claim 4, wherein a first light shielding member which shields the second image light is provided between the second incident diffraction grating and the first pupil expanding grating.

6. The image display device according to claim 1 or 2, wherein a relative position at which the first pupil expanding grating is disposed in the first optical member is different from a relative position at which the second pupil expanding grating is disposed in the second optical member.

7. The image display device according to claim 1 or 2, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The pitch of the first incident diffraction grating is larger than the pitch of the second incident diffraction grating, and the first incident diffraction grating diffracts the first image light at a smaller angle than the second incident diffraction grating diffracts the second image light.

8. The virtual image display device according to claim 1 or 2, wherein The first optical member is provided with the first incident diffraction grating and the first pupil expansion grating on one side, and is provided with the first exit diffraction grating on the other side opposite to the one side.

9. The virtual image display device according to claim 1 or 2, wherein The first incident diffraction grating diffracts image light of a first wavelength band included in the first image light, The virtual image display device has a second wavelength band optical member having a long wavelength band incident diffraction grating, a long wavelength band exit diffraction grating, and a long wavelength band pupil expansion grating, the long wavelength band incident diffraction grating diffracts image light of a second wavelength band included in the first image light and longer in wavelength than the first wavelength band, the long wavelength band exit diffraction grating causes the incident image light including the second wavelength band to exit toward a position at which the exit pupil is formed, and the long wavelength band pupil expansion grating causes the image light including the second wavelength band from the long wavelength band incident diffraction grating to be diffracted toward the long wavelength band exit diffraction grating.

10. The virtual image display device according to claim 9, wherein The height of the first incident diffraction grating is lower than the height of the long wavelength band incident diffraction grating.

11. The virtual image display device according to claim 9, wherein The second wavelength band optical member is provided between the first optical member and the second optical member.

12. The virtual image display device according to claim 1 or 2, wherein The virtual image display device further has: a third display element that exits third image light; and a fourth display element that exits fourth image light, The first optical member has a third incident diffraction grating that causes the third image light from the third display element to be incident and a third pupil expansion grating that causes the third image light from the third incident diffraction grating to be diffracted toward the first exit diffraction grating, The second optical member has a fourth incident diffraction grating that causes the fourth image light from the fourth display element to be incident and a fourth pupil expansion grating that causes the fourth image light from the fourth incident diffraction grating to be diffracted toward the second exit diffraction grating.

13. The virtual image display device according to claim 12, wherein The fourth incident diffraction grating is provided in the second optical member so as to overlap the third pupil expansion grating when viewed from the exit pupil, A second light shielding member that shields the fourth image light is provided between the fourth incident diffraction grating and the third pupil expansion grating.

14. The virtual image display device according to claim 12, wherein The pitch of the first incident diffraction grating is the same as the pitch of the third incident diffraction grating, The pitch of the second incident diffraction grating is the same as the pitch of the fourth incident diffraction grating.

Images