Near-to-eye display device and AR glasses

Abstract

The utility model relates to a near-to-eye display device and AR glasses, the near-to-eye display device comprises an LBS light engine used for emitting image light; the scattering element is used for diffusing the image light emitted by the LBS light engine; and a holographic optical element for redirecting reflecting the image light diffused by the scattering element to the retina for imaging. According to the near-to-eye display device, the primary real image is formed on the scattering element, and the scattering element is used for diffusing the divergence angle of the image light emitted by the LBS light engine, so that the near-to-eye display device can meet the large-aperture exit pupil design, can cover the movement range of human eyes and is suitable for different human eye pupil distances.

Description

TECHNICAL FIELD

[0001] The utility model relates to near-to-eye display technical field especially relates to a near-to-eye display device and AR glasses. BACKGROUND

[0002] With the development of near-to-eye display technology, a near-to-eye display scheme combining LBS (laser beam scanning) light engine and HOE (holographic optical element) appears. The near-to-eye display scheme is based on the principle of retinal projection near-to-eye display, focuses the light carrying virtual image emitted by the image source into a light beam, and converges the light beam into a point at the pupil of the human eye, and then directly projects onto the retina of the human eye. The near-to-eye display scheme has unique advantages in the field of near-to-eye display. First, this method greatly weakens the role of the lens in the human eye observation process. In the ideal case, the human eye observes a pair of full-focus depth-of-field pictures. Regardless of the focusing of the lens, the human eye can see a clear virtual picture. This advantage can effectively solve the problem of human eye focusing and vergence conflict of near-to-eye display devices, greatly reducing the risk of visual fatigue and dizziness caused by wearing near-to-eye display devices for a long time.

[0003] Although the near-to-eye display scheme based on retinal projection has obvious advantages, the light source is converged into a point in the imaging process, resulting in a small exit pupil diameter. On the one hand, during the rotation of the human eye, the virtual image light source cannot be incident on the retina, causing the picture to be lost. On the other hand, it is difficult to adapt to different human eye pupil distances. In addition, since the beam diameter of the LBS light engine is generally less than 0.7mm and the divergence angle is less than 1mrad, it is difficult to design a conventional large-aperture exit pupil. The exit pupil diameter that can be met is usually less than 1mm. SUMMARY

[0004] Therefore, it is necessary to provide a near-to-eye display device and AR glasses to solve the problem of small exit pupil diameter of the existing near-to-eye display scheme based on retinal projection.

[0005] A near-to-eye display device, comprising:

[0006] a LBS light engine for emitting image light;

[0007] a holographic optical element for redirecting and reflecting the image light on the retina to form an image; and

[0008] a scattering element located in the optical path between the LBS light engine and the holographic optical element, for diffusing the image light emitted by the LBS light engine to propagate to the holographic optical element, so that the holographic optical element redirects and reflects the diffused image light via the scattering element on the retina to form an image.

[0009] In one embodiment, the scattering element is a diffuse reflector, the LBS light engine is disposed on an incident side of the diffuse reflector, and the holographic optical element is disposed on a reflective side of the diffuse reflector.

[0010] In one embodiment, a surface of the diffuse reflector has a high reflective coating.

[0011] In one embodiment, the near-eye display device further comprises a curved mirror, the scattering element is a diffuse reflector, the holographic optical element is disposed on a reflective side of the diffuse reflector, the LBS light engine is disposed on an incident side of the curved mirror, and the diffuse reflector is disposed on a reflective side of the curved mirror.

[0012] In one embodiment, the scattering element is a transmissive diffuser element, the LBS light engine is disposed on an incident side of the transmissive diffuser element, and the holographic optical element is disposed on an exit side of the diffuser element.

[0013] In one embodiment, the transmissive diffuser element comprises a diffractive optical diffuser.

[0014] In one embodiment, the transmissive diffuser element comprises a refractive optical diffuser.

[0015] In one embodiment, an exit pupil diameter of the holographic optical element is greater than 8 mm.

[0016] In one embodiment, the LBS light engine comprises an LD element and a MEMS mirror, the LD element is disposed on an incident side of the MEMS mirror, and the scattering element is disposed on a reflective side of the MEMS mirror.

[0017] An AR eyeglass comprising:

[0018] The near-eye display device of any of the above; and

[0019] An eyeglass body, the near-eye display device being mounted to the eyeglass body.

[0020] The LBS light engine of the near-eye display device of the present application can play the role of a "light source", and can emit image light capable of carrying a virtual image based on an image source. The image light emitted by the LBS light engine has a small divergence angle. The scattering element can play the role of a "curtain", and the image light emitted by the LBS light engine can be projected to the scattering element along an optical path to form a first real image on the scattering element. Under the scattering effect of the scattering element, the image light emitted by the scattering element to the holographic optical element has a large divergence angle. The holographic optical element can play the role of an "eyepiece" and can reflect the diffused image light. The scattering element enlarges the range of the image light projected to the holographic optical element, increases the numerical aperture of the image light beam projected to the holographic optical element, and makes the near-eye display device of the present application have a large exit pupil diameter, so that the image light can always be projected to the retina. Compared with the LBS light engine directly emitting image light to the holographic optical element, the near-eye display device of the present application forms a first real image on the scattering element, diffuses the divergence angle of the image light emitted by the LBS light engine by using the scattering element, so that the near-eye display device of the present application can meet the design of a large-aperture exit pupil, can cover the movement range of the human eye and adapt to different human eye pupil distances. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 A light path schematic diagram of a near-eye display device provided for a first embodiment of the present application is shown in FIG. 1.

[0022] Figure 2 A light path schematic diagram of a near-eye display device provided for a second embodiment of the present application is shown in FIG. 2.

[0023] Reference signs: 10, LBS light engine; 11, LD element; 12, MEMS galvanometer; 21, diffuse reflection plate; 22, curved mirror; 23, transmissive diffuser element; 30, holographic optical element; 40, eyebox; 50, human eye. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0025] In the description of the utility model, it is understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0026] In addition, the terms "first" and "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first" and "second" can explicitly or implicitly include at least one of the features. In the description of the utility model, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise specifically limited.

[0027] In the utility model, unless otherwise specifically defined and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0028] In the utility model, unless otherwise specifically defined and limited, the first feature "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" of the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "below" and "below" of the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0029] It is to be understood that when an element such as a layer, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. It will be understood that, when a member is referred to as being "coupled" or "connected" to another member, it can be directly coupled or connected to the other member or intervening members can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding the syllables of a list of elements, modify the entire list of elements and do not modify the elements of the list individually. The term "about" when used before a numerical designation, has its ordinary meaning in the field of numerical specification, for example, it can mean a range of plus or minus ten percent of the numerical value of the numerical designation or it can mean a range of plus or minus 0.1%. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms are used herein for the purpose of illustration and are not intended to be limiting.

[0030] It is to be understood that when an element such as a layer, region or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements can be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. It will be understood that, when a member is referred to as being "coupled" or "connected" to another member, it can be directly coupled or connected to the other member or intervening members can be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Expressions such as "at least one of," when preceding the syllables of a list of elements, modify the entire list of elements and do not modify the elements of the list individually. The term "about" when used before a numerical designation, has its ordinary meaning in the field of numerical specification, for example, it can mean a range of plus or minus ten percent of the numerical value of the numerical designation or it can mean a range of plus or minus 0.1%. The terms "vertical", "horizontal", "upper", "lower", "left", "right", and similar terms are used herein for the purpose of illustration and are not intended to be limiting.

[0031] In particular, referring to Figure 1 and Figure 2 , the near-eye display device can include an LBS light engine 10, a scattering element, and a holographic optical element 30 arranged in sequence along an optical path. The LBS light engine 10 can be configured to emit image light. The holographic optical element 30 can be configured to reflect the image light diffused by the scattering element to the retina to form an image, so that the human eye 50 can see the image. The scattering element is located in the optical path between the LBS light engine 10 and the holographic optical element 30, and is configured to diffuse the image light emitted by the LBS light engine 10 to propagate to the holographic optical element 30, so that the holographic optical element 30 redirects the image light diffused by the scattering element to the retina to form an image.

[0032] It can be understood that the LBS light engine 10 of the near-eye display device can function as a "light source" and can emit image light carrying a virtual image based on an image source. The image light emitted by the LBS light engine 10 has a small divergence angle. The scattering element can function as a "curtain", and the image light emitted by the LBS light engine 10 can be directed to the scattering element along the optical path to form a real image on the scattering element. Under the scattering effect of the scattering element, the image light directed to the holographic optical element 30 by the scattering element has a large divergence angle. The holographic optical element 30 can function as an "eyepiece" and can reflect the diffused image light. The scattering element can enlarge the range of the image light projected onto the holographic optical element 30 and increase the numerical aperture of the image light beam projected onto the holographic optical element 30, so that the near-eye display device has a large exit pupil diameter, and the image light can always be projected onto the retina.

[0033] In this way, compared to the LBS light engine 10 directly emitting image light to the holographic optical element 30, the near-eye display device of this application forms a real image on the scattering element and uses the scattering element to diffuse the divergence angle of the image light emitted by the LBS light engine 10, so that the near-eye display device of this application can meet the design of a large aperture exit pupil, cover the range of motion of the human eye 50 and adapt to different human eye interpupillary distances.

[0034] Optionally, such as Figure 1 As shown, in some embodiments, the scattering element of this application is a diffuse reflector 21, the LBS light engine 10 is disposed on the incident side of the diffuse reflector 21, and the holographic optical element 30 is disposed on the reflective side of the diffuse reflector 21. The surface of the diffuse reflector 21 has a rough or irregular microstructure, which enables incident light to undergo diffuse reflection on its surface. When the image light emitted by the LBS light engine 10 enters the diffuse reflector 21, it is uniformly scattered in multiple directions through the microstructure of the surface of the diffuse reflector 21, so that the image light reflected from the diffuse reflector 21 to the holographic optical element 30 has a large divergence angle.

[0035] Optionally, in some embodiments, the microstructure of the surface of the diffuse reflector 21 of this application can be formed by mechanical processing methods such as grinding and sandblasting or by chemical etching.

[0036] Optionally, in some embodiments, the surface of the diffuse reflector 21 has a highly reflective coating. This highly reflective coating enhances the reflectivity of the diffuse reflector 21, thereby increasing its reflectivity. The highly reflective coating can be formed by applying a highly reflective material such as titanium dioxide or zinc oxide to the diffuse reflector 21.

[0037] Preferably, such as Figure 1 As shown, in some embodiments, the near-eye display device of this application further includes a curved reflector 22, the scattering element is a diffuse reflector 21, the holographic optical element 30 is disposed on the reflective side of the diffuse reflector 21, the LBS light engine 10 is disposed on the incident side of the curved reflector 22, and the diffuse reflector 21 is disposed on the reflective side of the curved reflector 22. The curved reflector 22 can reflect and adjust the propagation direction of image light. After the image light emitted by the LBS light engine 10 is projected onto the curved reflector 22, it is reflected by the curved reflector 22 and converged onto the diffuse reflector 21 to form a real image. With this arrangement, the optical path of the near-eye display device can be folded by the curved reflector 22, thereby enabling a more compact design of components such as the LBS light engine 10 and the diffuse reflector 21 in the near-eye display device, which is beneficial for the miniaturization and modularization of the near-eye display device.

[0038] Optionally, such as Figure 2As shown, in some embodiments, the scattering element of the present application is a transmissive diffuser element 23 (transmissive diffuser sheet element), the LBS light engine 10 is arranged on the incident side of the transmissive diffuser element 23, and the holographic optical element 30 is arranged on the exit side of the transmissive diffuser element 23. The transmissive diffuser element 23 can be used to uniformly diffuse the light beam, so that the light is uniformly distributed in multiple directions. When the image light emitted by the LBS light engine 10 is projected onto the transmissive diffuser element 23, a real image can be formed on the transmissive diffuser element 23. Through the diffusion effect of the transmissive diffuser element 23, a uniform scattering in multiple directions is formed, so that the image light transmitted through the transmissive diffuser element 23 to the holographic optical element 30 has a larger divergence angle.

[0039] Optionally, in some embodiments, the transmissive diffuser element 23 of the present application can include a diffractive optical element (DOE) or a refractive optical element (ROE). The diffractive optical element is based on the principle of optical diffraction, can include a plurality of diffraction units, and the image light is diffracted after passing through each diffraction unit of the diffractive optical element, and interference is generated at infinity or a focal plane to form a specific light intensity distribution. The refractive optical element is based on the principle of optical refraction, can include at least two refractive media with different refractive indices, and the image light is deflected when passing from a refractive medium with a low refractive index to a refractive medium with a high refractive index. The higher the refractive index of the refractive medium, the larger the deflection angle.

[0040] Optionally, in some embodiments, the exit pupil diameter of the holographic optical element 30 of the present application is greater than 8 mm. In this way, by designing a larger exit pupil diameter, the holographic optical element 30 of the present application can ensure that the image light is always focused on the retina during the rotation of the human eye 50. Further, it can also make the near-eye display device compatible with the needs of different human eye pupil distances.

[0041] Optionally, in some embodiments, the LBS light engine 10 of the present application includes an LD element 11 and a MEMS mirror 12, the LD element 11 is arranged on the incident side of the MEMS mirror 12, and the scattering element is arranged on the reflection side of the MEMS mirror 12. The LD element 11 is used to generate a laser beam, and the MEMS mirror 12 is used to make the laser beam emitted by the LD element 11 scan according to the route preset according to the image source, so as to be modulated into image light. The LBS light engine 10 composed of the LD element 11 and the MEMS mirror 12 has the characteristics of small size and light weight, which is more conducive to realizing the miniaturization and modularization of the near-eye display device.

[0042] The following embodiments are specific examples of the near-eye display device of this application.

[0043] like Figure 1 The diagram shown is a schematic representation of the optical path of a near-eye display device according to a first embodiment of this application. In this first embodiment, the near-eye display device may include an LD element 11, a MEMS galvanometer 12, a curved reflector 22, a diffuse reflector 21, and a holographic optical element 30 arranged sequentially along the optical path. The laser beam emitted by the LD element 11 is modulated into image light by the MEMS galvanometer 12 and then reflected towards the curved reflector 22. After the image light is adjusted in reflection direction by the curved reflector 22, it converges onto the diffuse reflector 21, forming a real image on the diffuse reflector 21. The diffuse reflector 21 reflects the image light to the holographic optical element 30 at a larger divergence angle. The holographic optical element 30 reflects the image light, causing the image light to pass through the eye box 40 and finally converge onto the retina of the human eye 50, thus completing the near-eye display.

[0044] like Figure 2 The diagram shown is a schematic representation of the optical path of a near-eye display device according to a second embodiment of this application. In this second embodiment, the near-eye display device may include an LD element 11, a MEMS galvanometer 12, a transmissive diffuser element 23, and a holographic optical element 30 arranged sequentially along the optical path. The laser beam emitted by the LD element 11 is modulated into image light by the MEMS galvanometer 12 and then reflected towards the transmissive diffuser element 23. The image light is formed in one step by the transmissive diffuser element 23. Through its own diffusion, the transmissive diffuser element 23 reflects the image light passing through it to the holographic optical element 30 at a larger divergence angle. The holographic optical element 30 reflects the image light, causing it to pass through the eye box 40 and finally converge onto the retina of the human eye 50, thus completing the near-eye display.

[0045] Furthermore, this application also provides AR glasses, which may include a near-eye display device and a glasses body as described above, with the near-eye display device mounted on the glasses body. Based on the large exit pupil diameter of the aforementioned near-eye display device, the AR glasses of this application ensure that the human eye can always see the image during use. Utilizing an LBS light engine and a retinal projection near-eye display scheme with holographic optical elements, the focusing-radius conflict problem of the human eye can be effectively solved, reducing visual fatigue and the risk of dizziness caused by prolonged wear of AR glasses. In addition, combined with the miniaturization and lightweight characteristics of the near-eye display device of this application, the overall structure of the AR glasses of this application is small and lightweight, making it suitable for prolonged wear.

[0046] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, as long as the combination of the technical features does not exist in contradiction, it shall be considered as within the scope of the present disclosure.

[0047] The above-described embodiments only express several implementation manners of the present application, the description is relatively specific and detailed, but it shall not be understood as a limitation on the scope of the present application patent. It should be pointed out that, for ordinary skilled in the art, under the premise of not departing from the concept of the present application, a number of modifications and improvements can be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the present application patent shall be subject to the appended claims.

Claims

1. A near-eye display device, comprising: Comprising: an LBS light engine for emitting image light; a holographic optical element for redirecting the image light to the retina for imaging; and a scattering element located in an optical path between the LBS light engine and the holographic optical element for diffusing the image light emitted by the LBS light engine to propagate to the holographic optical element so that the holographic optical element redirects the diffused image light via the scattering element to the retina for imaging.

2. The near-eye display device of claim 1, wherein, The scattering element is a diffuse reflector, the LBS light engine is disposed on an incident side of the diffuse reflector, and the holographic optical element is disposed on a reflective side of the diffuse reflector.

3. The near-eye display device of claim 2, wherein, The surface of the diffuse reflector has a high reflectance coating.

4. The near-eye display device of claim 1, wherein, The near-eye display device further comprises a curved mirror, the scattering element is a diffuse reflector, the holographic optical element is disposed on a reflective side of the diffuse reflector, the LBS light engine is disposed on an incident side of the curved mirror, and the diffuse reflector is disposed on a reflective side of the curved mirror.

5. The near-eye display device of claim 1, wherein, The scattering element is a transmissive diffuser element, the LBS light engine is disposed on an incident side of the transmissive diffuser element, and the holographic optical element is disposed on an exit side of the diffuser element.

6. The near-eye display apparatus of claim 5, wherein, The transmissive diffuser element comprises a diffractive optical diffuser.

7. The near-eye display apparatus of claim 5, wherein, The transmissive diffuser element comprises a refractive optical diffuser.

8. The near-eye display apparatus of any one of claims 1-6, wherein, The exit pupil diameter of the holographic optical element is greater than 8 mm.

9. The near-eye display apparatus of any one of claims 1-6, wherein, The LBS light engine comprises an LD element and a MEMS mirror, the LD element is disposed on an incident side of the MEMS mirror, and the scattering element is disposed on a reflective side of the MEMS mirror.

10. An AR eyeglass, characterized by, Comprising: the near-eye display device of any one of claims 1 to 9; and a spectacle body on which the near-eye display device is mounted.

Images