Display device

Abstract

The display device of the present embodiment includes an image display element (20, 20a to 20d), a light guide plate (10, 10a to 10d), a concave mirror (30, 30a to 30d), and two or more translucent mirrors (41, 41a to 41d; 42, 42a to 42d; 43, 43a, 43c, 43d). The image display element (20, 20a to 20d) is configured to emit light rays at a predetermined directivity angle (θ). The light guide plate (10, 10a to 10d) includes an incident surface (11, 11a to 11d) on which the light rays emitted from the image display element (20, 20a to 20d) are incident, a reflection surface (12, 12a to 12d) configured to reflect the light rays injected from the incident surface (11, 11a to 11d), and an exit surface (13, 13a to 13d) facing the reflection surface (12, 12a to 12d) to emit the light rays to the outside. The concave mirror (30, 30a to 30d) is configured to reflect the light rays reflected by the reflection surface (12, 12a to 12d) as parallel light. The two or more translucent mirrors (41, 41a to 41d; 42, 42a to 42d; 43, 43a, 43c, 43d) are configured to transmit a part of the parallel light reflected by the concave mirror (30, 30a to 30d) and reflect the remaining part of the parallel light to emit the remaining part from the light guide plate (10, 10a to 10d) to the outside, the translucent mirrors (41, 41a to 41d; 42, 42a to 42d; 43, 43a, 43c, 43d) being arranged side by side in a direction in which the parallel light travels inside the light guide plate (10, 10a to 10d). The concave mirror (30, 30a to 30d) reflects the light rays reflected by the reflection surface (12, 12a to 12d) to be incident on the translucent mirror (41, 41a to 41d) closest to the concave mirror (30, 30a to 30d) among the two or more translucent mirrors (41, 41a to 41d; 42, 42a to 42d; 43, 43a, 43c, 43d).

Description

TECHNICAL FIELD

[0001] The present application relates to a display device. BACKGROUND

[0002] In recent years, augmented reality (AR) glasses, which are display devices configured to superimpose and display a virtual reality image as a virtual image on the actual world by wearing a glasses-type device on the eyes, have been developed. Generally, the AR glasses are configured to include an image display element (display) configured to emit image light, a collimating optical system configured to convert the image light into parallel light (collimated light), and a light guide plate configured to repeatedly guide total reflection of the parallel light. Then, as a structure to take out the light rays guided inside the light guide plate to the outside to emit the light rays toward the human eyes, thereby expanding the eyebox in the light guide direction of the light rays. Here, the eyebox refers to a position range of the human eyes in which a virtual image composed of the light rays emitted from the light guide plate can be correctly observed as an image. There is a problem that this structure requires the collimating optical system, and thus it is difficult to reduce the size of the AR glasses. SUMMARY

[0003] Because this structure requires the collimating optical system, it is very difficult to reduce the size of the AR glasses. The present application is made in view of the above-described problem, and an object of the present application is to provide a display device capable of expanding the eyebox and suppressing the size.

[0004] To solve the above-described problem and achieve the object, a display device according to one embodiment includes an image display element, a light guide plate, a concave mirror, and two or more semi-transparent mirrors. The image display element is configured to emit light rays at a predetermined directivity angle. The light guide plate includes an incident surface on which the light rays emitted from the image display element are incident, a reflection surface configured to reflect the light rays injected from the incident surface, and an exit surface facing the reflection surface to emit the light rays to the outside. The concave mirror is configured to reflect the light rays reflected by the reflection surface as parallel light. The two or more semi-transparent mirrors are configured to transmit a part of the parallel light reflected by the concave mirror and reflect a remaining part of the parallel light to emit the remaining part from the light guide plate to the outside, the semi-transparent mirrors being arranged side by side in a direction in which the parallel light travels inside the light guide plate. The concave mirror reflects the light rays reflected by the reflection surface to be incident on the semi-transparent mirror closest to the concave mirror among the two or more semi-transparent mirrors.

[0005] According to the present application, it is possible to suppress disappearance of light rays to be guided, expand the eyebox, and suppress the size. BRIEF DESCRIPTION OF DRAWINGS

[0006] For a better understanding of the various implementations described herein, reference should be made to the Drawings where all Figures are of like numerals referring to like parts.

[0007] Figure 1 This is a diagram illustrating an example of the typical configuration of traditional AR glasses;

[0008] Figure 2 This is a diagram illustrating an example configuration of AR glasses according to an embodiment;

[0009] Figure 3 This is a diagram illustrating the behavior of light in AR glasses according to an embodiment;

[0010] Figure 4 It is a three-dimensional diagram illustrating the behavior of light in AR glasses according to an embodiment;

[0011] Figure 5 The illustration shows an example of wearing AR glasses while wearing regular glasses;

[0012] Figure 6 This is a diagram illustrating the configuration of the semi-transparent lens and λ / 4 of the AR glasses according to an embodiment, and the movement of light.

[0013] Figure 7 This is a diagram illustrating the configuration of AR glasses according to Example 1;

[0014] Figure 8 This is a diagram showing the distortion aberrations of the AR glasses according to Example 1;

[0015] Figure 9 This is a diagram illustrating the configuration of AR glasses according to Example 2;

[0016] Figure 10 This is a diagram showing the distortion aberrations of the AR glasses according to Example 2;

[0017] Figure 11 This is a diagram illustrating the configuration of AR glasses according to Example 3;

[0018] Figure 12 This is a diagram showing the distortion aberrations of the AR glasses according to Example 3;

[0019] Figure 13 This is a diagram illustrating the configuration of AR glasses according to Example 4;

[0020] Figure 14 This is a diagram showing the distortion aberrations of the AR glasses according to Example 4;

[0021] Figure 15 This is a diagram showing the glasses case of the AR glasses according to Example 4;

[0022] Figure 16 This is a diagram illustrating an example of configuring two or more AR glasses to expand the field of view according to Example 4. Detailed Implementation

[0023] Hereinafter, embodiments of a display device according to the present application will be described in detail with reference to the accompanying drawings. In addition, the present application is not limited to the following embodiments, and components in the following embodiments include components that can be easily conceived by those skilled in the art, substantially the same components, and so-called equivalent components. In addition, various omissions, substitutions, changes, and combinations of components can be made without departing from the spirit of the following embodiments.

[0024] (Configuration of Conventional AR Glasses)

[0025] Figure 1 is a diagram showing an example of a general configuration of conventional AR glasses 500. The configuration of the conventional general-purpose AR glasses 500 will be described with reference to Figure 1

[0026] As shown in Figure 1 , the AR glasses 500 include a light guide plate 100, an image display element 200, a collimating optical system 201, and semi-transparent mirrors 401 to 404.

[0027] The image display element 200 is a device configured to emit image light (hereinafter, can be simply referred to as light) that is the basis of an image to be displayed as a virtual image through the collimating optical system 201 and the light guide plate 100. The image display element 200 can employ various display elements such as an organic light emitting diode (OLED) and a liquid crystal display device. It should be noted that if the image display element 200 is capable of displaying information such as an image, a digital mirror device (DMD), a liquid crystal on silicon (LCOS), a laser display module obtained by combining a laser light source and a MEMS to be capable of displaying an image by scanning and projection, and the like can be used, for example. The digital mirror device is a micro electro mechanical system (MEMS) device in which a plurality of micromirrors (micro mirrors) are arranged on a plane.

[0028] The collimating optical system 201 is an optical system including one or more optical lenses, a diaphragm, or the like, and is configured to convert an angle of the image light emitted from the image display element 200 into a direction according to each pixel of the image display element, and convert the image light into parallel light.

[0029] The light guide plate 100 is a light guide configured to guide the light converted into parallel light by the collimating optical system 201 to be emitted toward the eye E of the user. The light guide plate 100 includes an incident surface 101 and an exit surface 103.

[0030] ​The incident surface 101 is a surface on which light rays converted into parallel light by the collimating optical system 201 are incident. The incident surface 101 is formed as a surface inclined at a predetermined angle with respect to a surface perpendicular to the exit surface 103 so as to inject light rays converted into parallel light by the collimating optical system 201 to guide them into the light guide plate 100. Light rays incident from the incident surface 101 as image light are guided inside the light guide plate 100 and reach the semi-transparent mirrors 401 to 404 while repeating total reflection on the exit surface 103 and a surface facing the exit surface 103.

[0031] The exit surface 103 is a surface through which light rays guided inside the light guide plate 100 are emitted toward the user's eye E by reflection on the semi-transparent mirrors 401 to 404.

[0032] The semi-transparent mirrors 401 to 404 are optical members configured to transmit some of the light rays guided inside the light guide plate 100 and reflect the remaining light rays. Further, the semi-transparent mirrors 401 to 404 are arranged side by side in a light guiding direction of the light rays inside the light guide plate 100 so that their reflecting surfaces have a predetermined angle (e.g., 45°) with respect to the exit surface 103. Further, from one close to the incident surface 101, the semi-transparent mirrors are the semi-transparent mirror 401, the semi-transparent mirror 402, the semi-transparent mirror 403, and the semi-transparent mirror 404 in this order. As described above, by arranging a plurality of semi-transparent mirrors like the semi-transparent mirrors 401 to 404, the eyebox EB10 is expanded in a left-right direction of the light guiding direction of the light rays (in the left-right direction). Figure 1 It should be noted that even if a diffractive optical element (DOE), a holographic optical element (HOE), or the like is applied instead of the semi-transparent mirrors 401 to 404, the eyebox EB10 can be expanded.

[0033] However, the configuration of the AR glasses 500 as described above has a problem that the collimating optical system 201 needs to be configured to make the image light emitted from the image display element 200 parallel, and thus the AR glasses 500 are large in overall size and heavy in weight. Further, the configuration also has a problem that, because the light rays incident on the light guide plate 100 are guided by repeating total reflection inside the light guide plate, if the surface precision of the light guide plate is not good, total reflection cannot be performed at accurate angles due to scattering or the like of the light rays, and thus the more the number of times of total reflection, the more errors occur, so that the image cannot be recognized correctly. In the following embodiments, a configuration of AR glasses that solves these problems will be described in detail.

[0034] (Configuration of AR glasses according to embodiments)

[0035] Figure 2 is a diagram showing an example of a configuration of AR glasses 1 according to an embodiment. The configuration of the AR glasses 1 will be described with reference to Figure 2The configuration of the AR glasses 1 according to the present embodiment will be described.

[0036] As Figure 2 shown, the AR glasses 1 according to the present embodiment include a light guide plate 10, an image display element 20, a concave mirror 30, a semi-transparent mirror 41 (first semi-transparent mirror), a semi-transparent mirror 42 (second semi-transparent mirror), and a semi-transparent mirror 43 (third semi-transparent mirror).

[0037] The light guide plate 10 is a light guide configured to guide image light (hereinafter, can be simply referred to as light) emitted from the image display element 20 and incident on the light guide plate 10, and emit the light toward the user's eye. The light guide plate 10 includes an incident surface 11, a reflection surface 12, and an exit surface 13.

[0038] The incident surface 11 is a surface on which the image light emitted from the image display element 20 is incident. The incident surface 11 is formed as a surface inclined at a predetermined angle (for example, 70°) with respect to the exit surface 13 (or the reflection surface 12), so as to cause the light that is the image light emitted from the image display element 20 to be incident thereon and guided inside the light guide plate 10. The image light injected from the incident surface 11 is directed toward the reflection surface 12.

[0039] The concave mirror 30 is formed inside the light guide plate 10, and has an action of concentrating the light totally reflected by the reflection surface 12. The reflection surface of the concave mirror 30 is an aspheric surface having a shape represented by, for example, the following equation (1).

[0040]

[0041] Here, the meanings of the characters in equation (1) are as follows.

[0042] z: sag with respect to a direction parallel to the optical axis of the concave mirror 30;

[0043] c: curvature at a surface vertex;

[0044] k: conic coefficient;

[0045] A, B, C, D, E, F, G, H, J: fourth, sixth, eighth, tenth, twelfth, fourteenth, sixteenth, eighteenth, and twentieth deformation coefficients (for example, in the case of a pure conic surface, A=B=C=D=E=F=G=H=J=0);

[0046] r: distance in a radial direction (represented by the following equation (2)).

[0047]

[0048] The light rays reflected by the concave mirror 30 are concentrated into parallel light. Here, the image light emitted from a certain pixel of the image display element 20 becomes light rays having a predetermined directivity angle, as described later in Figure 3 . The light rays having the directivity angle are totally reflected by the reflecting surface 12, become parallel light due to the concentrating effect of reflection on the concave mirror 30, and are emitted toward the semitransparent mirror 41 closest to the concave mirror 30. Furthermore, the light rays that have become parallel light by the concave mirror 30 are emitted as parallel light from the exit surface 13 even after being reflected by the semitransparent mirrors 41 to 43. It should be noted that the parallel light reflected by the concave mirror 30 does not simply mean strict parallel light, but includes light rays that can be regarded as parallel light.

[0049] It should be noted that the direction from the image display element 20 to the concave mirror 30, that is, the direction in which the image light emitted from the image display element 20 is guided, as well as the direction parallel to the reflecting surface 12 and the exit surface 13, is the y direction (y axis) in Figure 2 . The y direction corresponds to the up-down direction. Furthermore, the direction orthogonal to the y axis and orthogonal to the reflecting surface 12 and the exit surface 13 is the z direction (z axis), and the direction orthogonal to the y axis and the z axis and parallel to the reflecting surface 12 and the exit surface 13 is the x direction (x axis). The z direction corresponds to the depth direction, and the x direction corresponds to the horizontal direction.

[0050] The semitransparent mirrors 41 to 43 are optical members configured to transmit some of the light rays of the parallel light reflected by the concave mirror 30 and reflect the remaining light rays. Furthermore, the semitransparent mirrors 41 to 43 are arranged side by side inside the light guide plate 10 at positions close to the exit surface 13 in the direction of travel of the parallel light reflected by the concave mirror 30, such that their reflecting surfaces have a predetermined angle (for example, 45°) with respect to the exit surface. In other words, the semitransparent mirrors 41 to 43 are arranged such that their reflecting surfaces become parallel to each other. Furthermore, the semitransparent mirror 41, the semitransparent mirror 42, and the semitransparent mirror 43 are arranged in order from the side close to the concave mirror 30. In other words, the reflecting function of the semitransparent mirrors 41 to 43 makes it possible to reflect the light rays guided inside the light guide plate 10 and reflected by the concave mirror 30 and emit them from the exit surface 13, so that the user's eyes recognize them as a virtual image, and the transmissive function of the semitransparent mirrors 41 to 43 makes it possible to transmit the light of the outside world from the reflecting surface 12 toward the exit surface 12, and the user's ears recognize the actual world, thereby realizing augmented reality (AR).

[0051] (Behavior of light rays in AR glasses)

[0052] Figure 3 is a diagram that explains the behavior of light rays in AR glasses according to an embodiment. Figure 4 is a diagram that three-dimensionally shows the behavior of light rays in AR glasses according to an embodiment.Figure 5 is a diagram explaining that the AR glasses according to the embodiment can be worn while wearing glasses. The behavior of light rays in the AR glasses 1 according to the present embodiment will be described with reference to Figure 3 to Figure 5

[0053] As shown in FIG. 2, image light emitted from the pixels of the image display element 20 is first injected into the light guide plate 10 from the incident surface 11. Here, the image light is emitted from the pixels of the image display element 20 in a state in which diffusion is suppressed to have a predetermined directivity angle θ. In general, light emitted from pixels of an OLED, a liquid crystal display device, or the like is scattered light, but the image display element 20 of the AR glasses 1 according to the present embodiment emits image light in a state in which diffusion is suppressed to "directivity angle θ < 8°" (a semi-collimated state). Methods of suppressing diffusion of light rays emitted from the pixels of the image display element 20 include, for example, a method of concentrating light by providing a lenticular lens on the exit side of an R (red), G (green), and B (blue) color filter provided at each pixel, a method of physically suppressing diffusion by providing a physical partition at the boundary between pixels, and the like. As described above, by emitting image light from the pixels of the image display element 20 in a state in which diffusion is suppressed to "directivity angle θ < 8°", the image light can be totally reflected by the predetermined portion of the reflecting surface 12, and collision of light rays with the end portion 43EG of the semi-transparent mirror 43 located closest to the incident surface 11, which is located close to the reflecting surface 12, can be avoided to suppress occurrence of light ray loss. Figure 3

[0054] Here, the directivity angle is an angle obtained by doubling the angle at which the luminance is halved on the brightest central portion. In general, light emitted from pixels of an OLED, a liquid crystal display device, or the like is scattered light, but the image display element 20 of the AR glasses 1 according to the present embodiment emits image light in a state in which diffusion is suppressed to "directivity angle θ < 8°" (a semi-collimated state). Methods of suppressing diffusion of light rays emitted from the pixels of the image display element 20 include, for example, a method of concentrating light by providing a lenticular lens on the exit side of an R (red), G (green), and B (blue) color filter provided at each pixel, a method of physically suppressing diffusion by providing a physical partition at the boundary between pixels, and the like. As described above, by emitting image light from the pixels of the image display element 20 in a state in which diffusion is suppressed to "directivity angle θ < 8°", the image light can be totally reflected by the predetermined portion of the reflecting surface 12, and collision of light rays with the end portion 43EG of the semi-transparent mirror 43 located closest to the incident surface 11, which is located close to the reflecting surface 12, can be avoided to suppress occurrence of light ray loss.

[0055] Then, the light rays (image light) incident into the light guide plate 10 from the incident surface 11 head toward the reflecting surface 12, and are totally reflected by the reflecting surface 12. The light rays totally reflected by the reflecting surface 12 head toward the concave mirror 30. Here, because the directivity angle θ of the image light emitted from the image display element 20 is suppressed to be small, and thus the light rays totally reflected by the reflecting surface 12 in a state in which the width of the light beam is narrowed head toward the concave mirror 30, collision with the end portion 41EG of the semi-transparent mirror 41 located closest to the concave mirror 30, which is located close to the reflecting surface 12, can be avoided. As a result, occurrence of light ray loss can be suppressed.

[0056] ​​Before the light beam incident from the incident surface 11 is guided to the concave mirror 30, the total internal reflection occurs only once on the reflecting surface 12. As a result, light loss caused by light scattering due to repeated total internal reflection can be suppressed, and the accumulation of reflection angle errors caused by repeated total internal reflection can be suppressed. In other words, if the surface precision of the light guide plate is poor, there is a problem that total internal reflection cannot be performed at a precise angle due to light scattering, etc., and thus more errors occur. The greater the number of total internal reflections, the less correctly the image can be recognized. However, this problem can be solved in this embodiment because total internal reflection is performed only once.

[0057] Then, the light rays that are totally reflected by the reflecting surface 12 are reflected by the concave mirror 30 and become parallel light through the aforementioned focusing effect. In other words, because it includes conventional AR glasses (e.g., Figure 1 The light-focusing effect (conversion to parallel light) of the collimating optical system in the AR glasses 500 shown can be replaced by the light-focusing effect of reflection on the concave mirror 30, so the AR glasses 1 according to this embodiment does not require a collimating optical system. In other words, the AR glasses 1 has a configuration in which the image display element 20 is arranged outside the light guide plate 10. As a result, the overall size of the AR glasses 1 can be reduced and its weight can be lightened.

[0058] Then, the light rays, which become parallel by reflection on the concave mirror 30, directly reach the translucent mirror 41. Of the light rays incident on the translucent mirror 41, some are reflected and directed toward the exit surface 103, while the remaining light rays pass through the translucent mirror 41 and toward the translucent mirror 42. Of the light rays incident on the translucent mirror 42, some are reflected and directed toward the exit surface 103, while the remaining light rays pass through the translucent mirror 42 and toward the translucent mirror 43. Due to the properties of the quarter-wave plate and the polarizing dielectric multilayer film described later, the light rays incident on the translucent mirror 43 are reflected by the translucent mirror 43 and the head used for the exit surface 103, and the transmission of the translucent mirror 43 is suppressed. As described above, because the light rays reflected by the concave mirror 30 toward the translucent mirror 41 and the light rays passing through all the translucent mirrors 41 to 43 are suppressed, the occurrence of light loss can be suppressed.

[0059] Then, the light reflected by the translucent mirrors 41 to 43 is emitted from the exiting surface 13 toward the user's eye E. Furthermore, because the light becomes parallel through reflection on the concave mirror 30, the light to be reflected by the translucent mirrors 41 to 43 also becomes parallel. It should be noted that the parallel light reflected by the translucent mirrors 41 to 43 does not simply mean strictly parallel light, but includes light that can be considered parallel.

[0060] As described above, because multiple translucent mirrors such as translucent mirrors 41 to 43 are arranged side by side in the y-direction, therefore... Figure 3As shown, the eyebox EB formed by the AR glasses 1 can be expanded in the y direction. Here, in Figure 4 a perspective view of the AR glasses 1 is shown. Because the eyebox EB is also expanded in the z direction as the depth direction, and the exit pupil is expanded by the expansion of the eyebox EB in the y direction, the degree of freedom of the position of the eye point EPT indicating the position of the eye E of the user is improved. Furthermore, since the AR glasses do not have a configuration in which light rays are emitted to the outside by a pin mirror, disappearance of the light rays can be suppressed. It should be noted that, Figure 2 to Figure 4 the example of the AR glasses 1 shown has a configuration in which three half mirrors such as the half mirrors 41 to 43 are arranged, but the present embodiment is not limited thereto. The AR glasses can have a configuration in which two half mirrors are arranged, as long as the desired expansion of the eyebox EB can be achieved.

[0061] As described above, the AR glasses 1 according to the present embodiment need to cause the eye E of the user to recognize the image light emitted from the image display element 20 as a virtual image, and to recognize the light from the outside world that passes through the light guide plate 10. In other words, in general, even when the user wears the AR glasses 1 according to the present embodiment to enjoy the AR function, the user wearing the glasses cannot take off the glasses to clearly recognize the light (image) from the outside world. As described above, in the AR glasses 1 according to the present embodiment, the eyebox EB is expanded in the y direction by stacking the half mirrors, and the eyebox is also expanded in the depth direction (z direction). Furthermore, since the width of the display surface of the image display element 20 in the x direction is greater than the width in the z direction, the eyebox EB is expanded in the x direction, so the user can wear the AR glasses 1 in a state of wearing the glasses GL, as Figure 5 shown.

[0062] It should be noted that, in the examples shown in Figure 2 and Figure 3 , the reflecting surface 12 is located on the opposite side of the position of the eye E of the user wearing the AR glasses 1 with respect to the exit surface 13, but the present embodiment is not limited thereto. For example, the positions of the reflecting surface 12 and the exit surface 13 on which the half mirrors 41 to 43 are arranged can be reversed so that the exit surface 12 is located on the opposite side of the eye E of the user wearing the AR glasses 1 with respect to the reflecting surface 12. In this case, the image light emitted from the image display element 20 is totally reflected by the reflecting surface 12 located on the eye E side, and the light rays reflected by the half mirrors 41 to 43 arranged on the exit surface 13 side pass through the inside of the light guide plate 10, and are emitted outward (the eye E) from the reflecting surface 12 located on the eye E side.

[0063] (peripheral configuration of half mirrors)

[0064] Figure 6This is a diagram explaining the configuration of the semi-transparent lens and λ / 4 of the AR glasses according to an embodiment, and the movement of light. (Refer to...) Figure 6 The peripheral configuration of the semi-transparent lenses 41 to 43 of the AR glasses 1 according to this embodiment is described.

[0065] like Figure 6 As shown, the AR glasses 1 according to this embodiment further includes a quarter-wave plate 52a (first quarter-wave plate), a quarter-wave plate 52b (second quarter-wave plate), and a quarter-wave plate 53a (third quarter-wave plate). The quarter-wave plate 52a is arranged on the side of the semi-transparent mirror 41 of the semi-transparent mirror 42 and is parallel to the surface of the semi-transparent mirror. The quarter-wave plate 52b is arranged on the side of the semi-transparent mirror 43 of the semi-transparent mirror 42 and is parallel to the surface of the semi-transparent mirror. The quarter-wave plate 53a is arranged on the side of the semi-transparent mirror 42 of the semi-transparent mirror 43 and is parallel to the surface of the semi-transparent mirror.

[0066] Quarter-wave plates 52a, 52b, and 53a are phase plates configured to provide a phase difference of π / 2 (90°) to transmitted light. For example, quarter-wave plates 52a, 52b, and 53a convert linearly polarized light into circularly polarized light and vice versa. Furthermore, quarter-wave plates 52a, 52b, and 53a convert the S-polarization component of light into clockwise circularly polarized light and the P-polarization component into counterclockwise circularly polarized light. It should be noted that quarter-wave plates 52a, 52b, and 53a are preferably made of inorganic glass material instead of film material to improve surface finish.

[0067] Semi-transparent mirror 41 is provided with a non-polarizing dielectric multilayer film (an example of a non-polarizing film) and transmits some incident light while reflecting the rest without changing the polarization state of the light. Semi-transparent mirrors 42 and 43 are provided with polarization-separating dielectric multilayer films (examples of polarization-separating films) and reflect the S-polarization component of the incident light while transmitting the P-polarization component. For example, quarter-wave plates 52a, 52b, and 53a are made of crystal, and these configurations are established if two crystals are provided and a non-polarizing dielectric multilayer film or a polarization-separating dielectric multilayer film is formed on one surface of the crystal.

[0068] Reference Figure 6 The operation of light in the configuration of the translucent mirrors 41 to 43 and the quarter-wave plates 52a, 52b, and 53a as described above is explained. Figure 6 middle, Figure 6 (a) is a diagram illustrating the behavior of light rays incident on the approximate central portion of the translucent mirror 41 from the light reflected by the concave mirror 30. Figure 6 (b) is a diagram illustrating the behavior of light rays reflected by the concave mirror 30 that are incident on the portion of the translucent mirror 41 near the exiting surface 13.Figure 6 (c) is a diagram illustrating the behavior of the light rays of the light rays reflected by the concave mirror 30 that are incident on the portion of the semi-transparent mirror 41 near the reflecting surface 12.

[0069] As Figure 6 As shown in (a), of the light rays reflected by the concave mirror 30, a portion of the light rays incident on the approximately central portion of the semi-transparent mirror 41 is reflected by the semi-transparent mirror 41 and emitted to the outside from the exit surface 13, and the remaining light rays pass through the exit surface and are incident on the semi-transparent mirror 42. In this case, the light rays reflected by the semi-transparent mirror 41 and transmitted through the semi-transparent mirror 41 do not change to a polarized state. Furthermore, because the light rays transmitted through the semi-transparent mirror 41 pass through the quarter-wave plate 52a, but only the phase of the non-polarized light rays changes, the transmitted light rays are incident on the semi-transparent mirror 42 in a non-polarized state. Of the light rays incident on the semi-transparent mirror 42, for example, the light rays of the S-polarized component are reflected by the semi-transparent mirror 42 and again directed toward the quarter-wave plate 52a, and are converted by the quarter-wave plate 52a to, for example, clockwise circularly polarized light rays, and emitted to the outside from the exit surface 13. On the other hand, of the light rays incident on the semi-transparent mirror 42, the light rays of the P-polarized component pass through the semi-transparent mirror 42, are converted by the quarter-wave plate 52b to counterclockwise circularly polarized light rays, and are directed toward the semi-transparent mirror 43. Then, the counterclockwise circularly polarized light rays transmitted through the quarter-wave plate 52b are converted by the quarter-wave plate 53a to linearly polarized S-polarized light rays, and are incident on the semi-transparent mirror 43. Because the S-polarized light incident on the semi-transparent mirror 43 does not include a P-polarized component, all of the S-polarized light is reflected by the semi-transparent mirror 43 and again directed toward the quarter-wave plate 53a, and are converted by the quarter-wave plate 53a to clockwise circularly polarized light, and emitted to the outside from the exit surface 13.

[0070] As Figure 6(b) As shown, among the light rays reflected by the concave mirror 30, a portion of the light rays incident on the portion of the semi-transparent mirror 41 close to the exit surface 13 is reflected by the semi-transparent mirror 41 and emitted to the outside from the exit surface 13, and the remaining light rays pass through the semi-transparent mirror 41 and head toward the semi-transparent mirror 42. In this case, the light rays reflected by the semi-transparent mirror 41 and transmitted through the semi-transparent mirror 41 do not change to a polarized state. Furthermore, because the light rays transmitted through the semi-transparent mirror 41 pass through the quarter-wave plate 52a, but only the phase of the non-polarized light rays changes, the transmitted light rays are incident on the semi-transparent mirror 42 in a non-polarized state. Among the light rays incident on the semi-transparent mirror 42, the light rays of the S-polarization component are reflected by the semi-transparent mirror 42 and emitted to the outside from the exit surface 13. On the other hand, among the light rays incident on the semi-transparent mirror 42, the light rays of the P-polarization component pass through the semi-transparent mirror 42, are converted to counterclockwise circularly polarized light rays by the quarter-wave plate 52b, and head toward the semi-transparent mirror 43. Then, the counterclockwise circularly polarized light rays transmitted through the quarter-wave plate 52b are converted to linearly polarized S-polarized light rays by the quarter-wave plate 53a and are incident on the semi-transparent mirror 43. Because the S-polarized light incident on the semi-transparent mirror 43 does not include a P-polarization component, all of the S-polarized light is reflected by the semi-transparent mirror 43 and emitted to the outside from the exit surface 13.

[0071] As Figure 6 (c) As shown, among the light rays reflected by the concave mirror 30, a portion of the light rays incident on the portion of the semi-transparent mirror 41 close to the exit surface 13 is reflected by the semi-transparent mirror 41 and emitted to the outside from the exit surface 13, and the remaining light rays pass through the semi-transparent mirror 41 and head toward the semi-transparent mirror 42. In this case, the light rays reflected by the semi-transparent mirror 41 and transmitted through the semi-transparent mirror 41 do not change to a polarized state. Furthermore, because the light rays transmitted through the semi-transparent mirror 41 pass through the quarter-wave plate 52a, but only the phase of the non-polarized light rays changes, the transmitted light rays are incident on the semi-transparent mirror 42 in a non-polarized state. Among the light rays incident on the semi-transparent mirror 42, the light rays of the S-polarization component are reflected by the semi-transparent mirror 42 and emitted to the outside from the exit surface 13. On the other hand, among the light rays incident on the semi-transparent mirror 42, the light rays of the P-polarization component pass through the semi-transparent mirror 42, are converted to counterclockwise circularly polarized light rays by the quarter-wave plate 52b, and head toward the semi-transparent mirror 43. Then, the counterclockwise circularly polarized light rays transmitted through the quarter-wave plate 52b are converted to linearly polarized S-polarized light rays by the quarter-wave plate 53a and are incident on the semi-transparent mirror 43. Because the S-polarized light incident on the semi-transparent mirror 43 does not include a P-polarization component, all of the S-polarized light is reflected by the semi-transparent mirror 43 and emitted to the outside from the exit surface 13.

[0072] On the other hand, among the light rays that pass through the half mirror 41 and are incident on the half mirror 42, the light rays of the P-polarization component pass through the half mirror 42, are converted into counterclockwise circularly polarized light rays by the quarter wave plate 52b, and head toward the half mirror 43. Then, the counterclockwise circularly polarized light rays that are transmitted through the quarter wave plate 52b are converted into linearly polarized S-polarization light rays by the quarter wave plate 53a, and are incident on the half mirror 43. Because the S-polarization light that is incident on the half mirror 43 does not include a P-polarization component, all of the S-polarization light is reflected by the half mirror 43, heads toward the quarter wave plate 53a again, is converted into clockwise circularly polarized light by the quarter wave plate 53a, and heads toward the half mirror 42 again. The clockwise circularly polarized light that heads toward the half mirror 42 again is converted into P-polarization light by the quarter wave plate 52b, and is incident on the half mirror. Because the P-polarization light that is incident on the half mirror 42 does not include an S-polarization component, all of the P-polarization light passes through the half mirror 42, is converted into counterclockwise circularly polarized light by the quarter wave plate 52a, and is emitted to the outside from the exit surface 13.

[0073] As described above, according to the configuration of the half mirrors 41 to 43 and the quarter wave plates 52a, 52b, and 53a, the light rays that are reflected by the concave mirror 30 are reflected by any one of the half mirrors 41 to 43 to be emitted from the exit surface 13, and do not pass through the half mirror 43. Therefore, because the light rays that are transmitted through the half mirror 43 are suppressed, it is possible to suppress the occurrence of light ray loss.

[0074] As described above, the AR glasses 1 according to the present embodiment include the image display element 20 configured to emit light rays of a predetermined directivity angle θ from a pixel, the light guide plate 10 including an incident surface 11 on which the light rays emitted from the image display element 20 are incident, a reflection surface 12 configured to totally reflect the light beams incident from the incident surface 11 only once, and an exit surface 13 facing the reflection surface 12 to emit the light rays to the outside, the concave mirror 30 configured to reflect the light rays totally reflected by the reflection surface 12 as parallel light, and the semi-transparent mirrors 41 to 43 configured to transmit a part of the parallel light reflected by the concave mirror 30 and reflect a remaining part of the parallel light to emit the remaining part from the exit surface 13 to the outside, the semi-transparent mirrors being arranged side by side in a direction in which the parallel light travels inside the light guide plate 10. The concave mirror 30 reflects the light rays totally reflected by the reflection surface 12 to be incident on the semi-transparent mirror 41 closest to the concave mirror 30 among the semi-transparent mirrors 41 to 43. As described above, because the number of times of total reflection is only one on the reflection surface 12 until the light beams injected from the incident surface 11 are guided to the concave mirror 30, occurrence of loss of light rays due to scattering or the like of the light rays caused by repetition of total reflection can be suppressed, and accumulation of reflection angle errors caused by repetition of total reflection can be suppressed. Further, because the semi-transparent mirrors 41 to 43 are arranged side by side in the direction in which the parallel light travels inside the light guide plate 10, the eye box can be expanded. Further, because the AR glasses 1 do not include the collimating optical system included in the conventional AR glasses, but include the concave mirror 30 to replace a function of the collimating optical system, the overall size of the AR glasses 1 can be reduced and the weight can be lightened. Thus, with the configuration of the AR glasses 1 according to the present embodiment, disappearance of the light rays to be guided can be suppressed, the eye box can be expanded, and the size can be suppressed.

[0075] Further, the AR glasses 1 according to the present embodiment have a directivity angle θ of less than 8°. As described above, by emitting the image light from the pixel of the image display element 20 in a state in which diffusion is suppressed, the image light can be totally reflected on an intended part of the reflection surface 12, thereby suppressing occurrence of loss of light rays.

[0076] Further, in the AR glasses 1 according to the present embodiment, the semi-transparent mirrors 41 to 43 are arranged on the exit surface 13 side inside the light guide plate 10, the image display element 20 emits the light rays toward the reflection surface 12 so as not to collide with an end portion 43EG of the semi-transparent mirror 43 closest to the reflection surface 12 among the semi-transparent mirrors 41 to 43, and the reflection surface 12 totally reflects the light rays so as not to collide with an end portion 41EG of the semi-transparent mirror 41 closest to the reflection surface 12 among the semi-transparent mirrors 41 to 43. As a result, occurrence of loss of light rays can be suppressed.

[0077] Further, in the AR glasses 1 according to the present embodiment, of the semi-transparent mirrors 41 to 43, the semi-transparent mirror 41 closest to the concave mirror 30 is provided with a non-polarizing dielectric multilayer film, and the semi-transparent mirror 42 arranged next to the semi-transparent mirror 42 and the semi-transparent mirror 43 closest to the incident surface 11 are provided with a polarization-separating dielectric multilayer film. The AR glasses 1 further include a quarter-wave plate 52a arranged on the semi-transparent mirror 41 side of the semi-transparent mirror 42, a five-eighths wave plate 52b arranged on the semi-transparent mirror 43 side of the semi-transparent mirror 42, and a seven-eighths wave plate 53a arranged on the semi-transparent mirror 42 side of the semi-transparent mirror 43. As a result, the light rays reflected by the concave mirror 30 are reflected by any one of the semi-transparent mirrors 41 to 43 to be emitted from the exit surface 13, and do not pass through the semi-transparent mirror 43. Therefore, since the light rays transmitted through the semi-transparent mirror 43 are suppressed, occurrence of light ray loss can be suppressed.

[0078] Hereinafter, specific examples of the AR glasses 1 will be described by using Examples 1 to 4.

[0079] (Example 1)

[0080] Figure 7 is a diagram showing the structure of the AR glasses 1a of Example 1. Figure 8 is a diagram showing the distortion aberration of the AR glasses 1a of Example 1. The AR glasses 1a of Example 1 will be described with reference to Figure 7 and Figure 8 .

[0081] Figure 7 The AR glasses 1a shown in Table 1 shown below are specific examples of applying various dimensions and angles shown in the table 1 and light guide plate glass materials to the AR glasses 1 according to the above-described embodiments. The light guide plate 10a, the incident surface 11a, the reflection surface 12a, the exit surface 13a, the image display element 20a, the concave mirror 30a, and the semi-transparent mirrors 41a to 43a in the AR glasses 1a according to the present example respectively correspond to the light guide plate 10, the incident surface 11, the reflection surface 12, the exit surface 13, the image display element 20, the concave mirror 30, and the semi-transparent mirrors 41 to 43 in the AR glasses 1 according to the above-described embodiments. Further, the concave mirror 30a is an aspherical mirror as described above.

[0082] Table 1

[0083]

[0084]

[0085] In the pupil distance shown in Table 1, the pupil distance EP is the distance from the light guide plate 10a (exit surface 13a) to the position of the user's eye (eye point). The pupil diameter AP is the width in the y direction (array direction of the half-transparent mirrors 41a to 43a) through which one of the half-transparent mirrors can be displayed as an image. The pupil interval APD is the interval of the images generated by the light rays reflected by the half-transparent mirrors, that is, the interval in the y direction between the half-transparent mirrors, and is the same as the mirror interval MD. The difference between the pupil interval PDD and the pupil diameter AP (APD-AP) indicates the width in the y direction through which the light rays pass at the position of the pupil distance EP. The light guide plate thickness WGD is the thickness of the light guide plate 10a, that is, the distance between the reflecting surface 12a and the exit surface 13a. The eyebox V direction EBV is the vertical direction (y direction) width of the eyebox formed by the AR glasses 1a. The eyebox H direction EBH is the horizontal direction (x direction) width of the eyebox formed by the AR glasses 1a. The display surface interval DD is the distance from the incident surface 11a to the display surface (exit surface) of the image display element 20a. The display element short side direction DV is the length in the short side direction (direction from the reflecting surface 12a to the exit surface 13a) of the image display element 20a. The display element long side direction DH is the length in the long side direction (horizontal direction, x direction) of the image display element 20a. The vertical field of view (VFOV: vertical field of view) is the angle of view in the vertical direction (y direction). The horizontal field of view (HFOV: horizontal field of view) refers to the angle of view in the horizontal direction (x direction). The diagonal field of view (DFOV: diagonal Field Of View) is the angle of view in the diagonal direction. The display element short side angle of emission (VDang) is the angle of emission in the YZ plane of the image light emitted from the pixel of the image display element 20a, and corresponds to the above-mentioned directivity angle θ. The display element size IMS is the length in the diagonal direction of the image display element 20a. The refractive index RIX is the refractive index of the glass material constituting the light guide plate 10a. The Abbe number An is the Abbe number of the glass material constituting the light guide plate 10a.

[0086] By configuring the AR glasses 1a according to the above-described Table 1, it is possible to suppress the distortion aberration as shown in Figure 8 It should be noted that Figure 8 The distortion aberration shown in Table 1 shows the distortion aberration on the display surface of the image display element 20a when the image is formed by reverse tracing on the display surface from the exit pupil side. By adopting such a configuration, the AR glasses 1a have the same effects as the AR glasses 1 according to the above-described embodiment.

[0087] Further, since the diameter of a human pupil is approximately at least 2 [mm], the user can visually recognize an image having sufficient brightness by setting the "pupil interval APD-pupil diameter AP" to 1 [mm] or less as in Table 1. Further, as shown in Table 1, it is desirable to set the pupil diameter AP to 2 [mm] or more which is the minimum value of the diameter of a human pupil.

[0088] (Example 2)

[0089] Figure 9 is a diagram representing the structure of the AR glasses 1b of Example 2. Figure 10 is a diagram representing the distortion aberration of the AR glasses 1b of Example 2. The AR glasses 1b of Example 2 will be described with reference to Figure 9 and Figure 10 .

[0090] Figure 9 The AR glasses 1b shown in the diagram represent a specific example in which the various dimensions and angles shown in Table 2 below and the light guide plate glass material are applied to the AR glasses 1 according to the above-described embodiment. The light guide plate 10b, the incident surface 11b, the reflecting surface 12b, the exit surface 13b, the image display element 20b, and the concave mirror 30b in the AR glasses 1b according to the present example respectively correspond to the light guide plate 10, the incident surface 11, the reflecting surface 12, the exit surface 13, the image display element 20, and the concave mirror 30 in the AR glasses 1 according to the above-described embodiment. Further, instead of the semi-transparent mirrors 41 to 43 in the above-described AR glasses 1, the AR glasses 1b according to the present example include two semi-transparent mirrors (semi-transparent mirrors 41b and 42b). Further, the concave mirror 30b is an aspherical mirror as described above.

[0091] Table 2

[0092] Name Symbol Value Unit Pupil distance EP 15 millimeters Pupil vertical APV 3.5 millimeters Pupil horizontal APH 8 millimeters Pupil separation APD 4.5 millimeters Pupil separation-pupil vertical APD-APV 1 millimeters Mirror separation MD 4.5 millimeters Waveguide thickness WGD 13.1 millimeters Eyebox V direction EBV 8 millimeters Eyebox H direction EBH 8 millimeters Display surface separation DD 1 millimeters Display element short side direction DV 5.33 millimeters Display element long side direction DH 10.99 millimeters Vertical field of view VFOV 10.0 ° Horizontal field of view HFOV 20.0 ° Diagonal field of view DFOV 22.5 ° Display element short side pop-out angle VDang 6.6 ° Display element size IMS 0.48 inches Refractive index RIX 1.923 - Abbe number AN 20.88 -

[0093] The various dimensions and angles shown in Table 2 and the light guide plate glass material have meanings similar to those in Table 1 described above, but in Table 2, the pupil vertical APV and the pupil horizontal APH are prescribed instead of the pupil diameter AP of Table 1, and in Table 2, the difference (APD-APV) between the pupil interval APD and the pupil vertical APV is specified instead of the difference (APD-AP) between the pupil interval APD and the pupil diameter AP of Table 1. The pupil vertical APV is a width in the y direction (vertical direction, array direction of the semi-transparent mirrors 41b and 42b) through which one of the semi-transparent mirrors can be displayed as an image. The pupil horizontal APH is a width in the x direction (horizontal direction) through which one of the semi-transparent mirrors 41b and 42b can be displayed as an image.

[0094] By configuring the AR glasses 1b according to the above-described Table 2, distortion aberration can be suppressed as shown in Figure 10 It should be noted that Figure 10 The distortion aberration shown in FIG. 6B shows the distortion aberration on the display surface of the image display element 20b when an image is formed by reverse tracing on the display surface from the exit pupil side. By adopting such a configuration, the AR glasses 1b have the same effects as the AR glasses 1 according to the above-described embodiment.

[0095] Further, since the diameter of a human pupil is approximately at least 2 [mm], a user can visually recognize an image having sufficient brightness by setting the "pupil interval APD-pupil vertical APV" to 1 [mm] or less as in Table 2. Further, as shown in Table 2, it is desirable to set the pupil vertical APV to 2 [mm] or more, which is the minimum value of the diameter of a human pupil.

[0096] (Example 3)

[0097] Figure 11 is a diagram that represents the structure of the AR glasses 1c of Example 3. Figure 12 is a diagram that represents the distortion aberration of the AR glasses 1c of Example 3. The AR glasses 1c of Example 3 will be described with reference to Figure 11 and Figure 12 The AR glasses 1c according to Example 3 will be described.

[0098] Figure 11 The AR glasses 1c shown in FIG. 6A represents a specific example of applying the various dimensions and angles shown in Table 3 below and the light guide plate glass material to the AR glasses 1 according to the above-described embodiment. The light guide plate 10c, the incident surface 11c, the reflection surface 12c, the exit surface 13c, the image display element 20c, the concave mirror 30c, and the semi-transparent mirrors 41c to 43c in the AR glasses 1c according to the present example respectively correspond to the light guide plate 10, the incident surface 11, the reflection surface 12, the exit surface 13, the image display element 20, the concave mirror 30, and the semi-transparent mirrors 41 to 43 in the AR glasses 1 according to the above-described embodiment. Further, the concave mirror 30c is an aspherical mirror as described above.

[0099] Table 3

[0100]

[0101]

[0102] The meanings of the various dimensions and angles shown in Table 3 and the light guide plate glass material are similar to those of Table 2 described above.

[0103] By configuring the AR glasses 1c according to the above-described Table 3, distortion aberration can be suppressed as shown in Figure 12 It should be noted that Figure 12The distortion aberration diagram illustrated in FIG. 6 illustrates a distortion aberration on the display surface of the image display element 20c when an image is formed by reverse tracing on the display surface from the exit pupil side. By adopting such a configuration, the AR glasses 1c have the same effect as the AR glasses 1 according to the above-described embodiment.

[0104] Further, since the diameter of a human pupil is approximately at least 2 [mm], the user can visually recognize an image having sufficient brightness by setting the "pupil interval APD-pupil vertical APV" to 1 [mm] or less as illustrated in Table 3. Further, as illustrated in Table 3, it is desirable to set the pupil vertical APV to 2 [mm] or more which is the minimum value of the diameter of a human pupil.

[0105] (Example 4)

[0106] Figure 13 is a diagram representing the structure of the AR glasses 1d of Example 4. Figure 14 is a diagram representing the distortion aberration of the AR glasses 1d of Example 4. Figure 15 is a diagram illustrating the eyebox of the AR glasses 1d according to Example 4. Figure 16 is a diagram illustrating an example of arranging two or more AR glasses to expand the visual angle according to Example 4. The AR glasses 1d according to Example 4 will be described with reference to Figure 13 to Figure 16

[0107] Figure 13 The AR glasses 1d illustrated in FIG. 6 represent a specific example of applying the various dimensions and angles illustrated in Table 4 below and the light guide plate glass material to the AR glasses 1 according to the above-described embodiment. The light guide plate 10d, the incident surface 11d, the reflecting surface 12d, the exit surface 13d, the image display element 20d, the concave mirror 30d, and the semi-transparent mirrors 41d to 43d in the AR glasses 1d according to the present example respectively correspond to the light guide plate 10, the incident surface 11, the reflecting surface 12, the exit surface 13, the image display element 20, the concave mirror 30, and the semi-transparent mirrors 41 to 43 in the AR glasses 1 according to the above-described embodiment.

[0108] Table 4

[0109]

[0110]

[0111] The meanings of the various dimensions and angles illustrated in Table 4 and the light guide plate glass material are similar to those of Table 2 described above. Further, the reflecting surface of the concave mirror 30d is a deformed aspherical surface having a shape represented by the following equation (3).

[0112] ​

[0113] Here, the meanings of the characters in Equation (3) are as follows.

[0114] z: sag amount with respect to the direction parallel to the optical axis of the concave mirror 30d;

[0115] CUX, CUY: curvatures of x and y;

[0116] KX, KY: quadratic curve coefficients of x and y;

[0117] AR, BR, CR, DR: rotational symmetries of the fourth, sixth, eighth, and tenth deformations of the conic curve;

[0118] AP, BP, CP, DP: non-rotational symmetries of the fourth, sixth, eighth, and tenth deformations of the conic curve;

[0119] (ordinary aspherical surface in the case of CUX = CUY, KX = KY, and AP = BP = CP = DP = 0).

[0120] By configuring the AR glasses 1d according to Table 4 described above, it is possible to suppress distortion aberration, as shown in Figure 14 It should be noted that Figure 14 the distortion aberration shown in

[0121] Further, since the diameter of the human pupil is approximately at least 2 [mm], the user can visually recognize an image having sufficient brightness by setting the “pupil interval APD-pupil vertical APV” to 1 [mm] or less, as shown in Table 4. Further, as shown in Table 4, it is desirable to set the pupil vertical APV to 2 [mm] or more, which is the minimum value of the diameter of the human pupil.

[0122] Further, by employing the concave mirror 30d having a deformation aspherical surface, as shown in Figure 15 compared to Embodiments 1 to 3, the eyebox EBd can be further expanded in the z direction, and the user can recognize an image by using a position away from the exit surface 13d as the eye point EPT. Further, by expanding the eyebox EBd in the z direction, by using three AR glasses 1d-1 to 1d-3 having the same configuration as the configuration of the AR glasses 1d, their exit surfaces are obliquely arranged, and their eyeboxes EBd are arranged to overlap at the eye point EPT, as shown in Figure 16 to be able to expand the visual angle in the horizontal direction.

[0123]

Explanation of letters or numbers

[0124] 1, 1a to 1d, 1d-1 to 1d-3 AR glasses

[0125] 10, 10a to 10d light guide plate

[0126] 11, 11a to 11d incident surface

[0127] 12, 12a to 12d reflecting surface

[0128] 13, 13a to 13d exit surface

[0129] 20, 20a to 20d image display element

[0130] 30, 30a to 30d concave mirror

[0131] 41, 41a to 41d semi-transparent mirror

[0132] 41 EG end

[0133] 42, 42a to 42d semi-transparent mirror

[0134] 43, 43a, 43c, 43d semi-transparent mirror

[0135] 43 EG end

[0136] 52a, 52b, 53a quarter wave plate

[0137] 100 light guide plate

[0138] 101 incident surface

[0139] 103 exit surface

[0140] 200 image display element

[0141] 201 collimating optical system

[0142] 401 to 404 semi-transparent mirror

[0143] 500 AR glasses

[0144] E eye

[0145] EB, EBd, EB10 eyebox

[0146] EPT eye point

[0147] GL glasses

[0148] θ pointing angle

Claims

1. A display device, characterized by comprising: Comprising: an image display element configured to emit light rays at a predetermined directivity angle; a light guide plate including an incident surface on which the light rays emitted from the image display element are incident, a reflection surface configured to reflect the light rays injected from the incident surface, and an exit surface facing the reflection surface to emit the light rays to the outside; a concave mirror configured to reflect the light rays reflected by the reflection surface as parallel light; two or more translucent mirrors configured to transmit a part of the parallel light reflected by the concave mirror and reflect a remaining part of the parallel light to emit the remaining part from the light guide plate to the outside, the translucent mirrors being arranged side by side in a direction in which the parallel light travels inside the light guide plate, wherein the concave mirror reflects the light rays reflected by the reflection surface to be incident on a translucent mirror closest to the concave mirror among the two or more translucent mirrors; the two or more translucent mirrors are arranged along an exit surface side in the light guide plate, the light rays incident from the incident surface being totally reflected only once by the reflection surface of the light guide plate toward the concave mirror.

2. The display device of claim 1, wherein, The directivity angle is less than 8°.

3. The display device of any of claims 1-2, wherein, The number of the translucent mirrors is three.

4. The display device of claim 3, wherein, Among the three translucent mirrors, a first translucent mirror closest to the concave mirror is provided with a non-polarizing film, and each of a second translucent mirror arranged next to the first translucent mirror and a third translucent mirror closest to the incident surface is provided with a polarization separation film configured to reflect an S-polarization component of the incident light rays and transmit a P-polarization component, and the display device further includes a first quarter wave plate arranged on the first translucent mirror side of the second translucent mirror, a second quarter wave plate arranged on the third translucent mirror side of the second translucent mirror, and a third quarter wave plate arranged on the second translucent mirror side of the third translucent mirror.

5. The display device of any of claims 1-2, wherein, The reflection surface of the concave mirror includes an aspheric surface.

6. The display device of any of claims 1-2, wherein, The reflection surface of the concave mirror includes a deformed aspheric surface.

7. The display device of any of claims 1-2, wherein, A difference between a separation of an image produced by the light rays reflected by the translucent mirrors and an array direction width of the image of the translucent mirrors is not more than 1 mm.

8. The display device of any of claims 1-2, wherein, An image visually recognizable by the parallel light that can be reflected by the translucent mirrors has a width in a traveling direction of not less than 2 mm.

9. The display device of claim 6, wherein, A horizontal direction view angle can be widened by arranging a plurality of the display devices such that their exit surfaces are inclined to make their eye boxes overlap with each other.

10. The display device of any of claims 1-2, wherein, Each of the translucent mirrors is arranged at 45° with respect to the exit surface.

11. The display device of any of claims 1-2, wherein, The reflection surface is located on an opposite side of a position of an eye of a person wearing the display device with respect to the exit surface.

12. The display device of any of claims 1-2, wherein, The exit surface is located on an opposite side of a position of an eye of a person wearing the display device with respect to the reflection surface.

13. The display device of any of claims 1-2, wherein, The image display element corrects color separation of the light guide plate by moving images of each color composed of pixels of a display surface to emit light rays of the images of each color.

14. The display device of claim 4, wherein, The first quarter wave plate, the second quarter wave plate, and the third quarter wave plate are made of an inorganic glass material.

15. The display device of any of claims 1-2, wherein, The image display element faces the incident surface.

16. The display device of any of claims 1-2, wherein, A width of a display surface of the image display element in a direction orthogonal to a direction from the reflection surface to the exit surface and parallel to the incident surface is larger than a width in the direction from the reflection surface to the exit surface.

17. The display device of any one of claims 1-2, wherein, Light reflected by the semi-transparent mirror is parallel light.

18. The display device of any of claims 1-2, wherein, The parallel light reflected by the concave mirror directly reaches the semi-transparent mirror closest to the concave mirror.

19. The display device of any of claims 1-2, wherein, The incident surface is formed as a surface inclined by a predetermined angle with respect to the exit surface.

Images