AR device
By using a combination of embossed gratings and holographic gratings in AR devices, the diffraction angle of external light beams is increased, solving the rainbow effect problem in AR devices and improving user experience and image quality.
Patent Information
- Application Number
- CN202520320948.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2026-01-13
- Estimated Expiration
- 2035-02-26
AI Technical Summary
The detached area in AR devices is sensitive to ambient light, causing a rainbow effect that affects image clarity and user experience.
The design employs a combination of relief gratings and holographic gratings, with the relief grating period being larger than the holographic grating period. This increases the diffraction angle of the external light beam, allowing the external light beam to couple out of the optical waveguide body at a larger angle, thus reducing the amount of external light beam entering the user's field of vision.
It effectively reduces the rainbow effect, improves the user experience, and enhances image clarity and immersion.
Smart Images
Figure CN223796765U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of AR devices, and more specifically, to an AR device. Background Technology
[0002] Augmented Reality (AR) technology is widely used in various fields such as gaming, education, and healthcare. AR devices provide users with an immersive experience by combining virtual information with the real world. As one of the key hardware components of AR technology, AR glasses need to possess characteristics such as lightweight design, high resolution, a large field of view (FOV), high brightness, and low power consumption to meet users' needs for wearing comfort and experience. The optical display system in AR glasses typically uses waveguide display technology, with waveguide sheets as its core component. Waveguide sheets split, guide, and output the image beam of the optomechanical display to achieve the transmission and display of virtual images.
[0003] In related technologies, an optomechanical system sends an image beam to a waveguide sheet, and a coupling region on the waveguide sheet couples out the image beam propagating within the waveguide sheet, so as to project the image beam sent by the optomechanical system in a specific direction to form a display content visible to the human eye.
[0004] However, because the coupling region is highly sensitive to ambient light, when ambient light shines on it, it disperses different wavelengths of light into rainbow beams or colored stripes, resulting in a rainbow effect. This rainbow effect not only reduces the sharpness and contrast of the image but also disrupts the immersive experience of the augmented reality system and can even cause eye strain during prolonged use, thus negatively impacting the user experience. Summary of the Invention
[0005] In view of the above problems, this application proposes an AR device that can effectively reduce the rainbow effect.
[0006] In a first aspect, embodiments of this application provide an AR device, which includes: an optical engine and an optical waveguide; the optical waveguide includes an optical waveguide body, an entrance pupil region, and an exit pupil region; the exit pupil region includes an embossed grating and a holographic grating disposed on one side of the embossed grating, and the optical waveguide body is disposed on the other side of the embossed grating; the optical engine is used to emit an image beam into the entrance pupil region; the holographic grating is used to increase the diffraction angle of the coupled external beam; the period of the embossed grating is greater than the period of the holographic grating.
[0007] The technical solution provided in this application includes an AR device comprising: an optical engine and an optical waveguide; the optical waveguide includes a waveguide body, an entrance pupil region, and an exit pupil region; the exit pupil region includes an embossed grating and a holographic grating disposed on one side of the embossed grating, and the optical waveguide body is disposed on the other side of the embossed grating; the optical engine is used to emit an image beam into the entrance pupil region; the holographic grating is used to increase the diffraction angle of the coupled external beam; the period of the embossed grating is greater than the period of the holographic grating. Thus, through the cooperation of the embossed grating and the holographic grating, the external beam is coupled out of the optical waveguide body with a larger diffraction angle, thereby reducing the amount of external beam entering the user's field of vision, reducing the rainbow effect, and improving the user experience. Attached Figure Description
[0008] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments and drawings obtained by those skilled in the art without creative effort are within the scope of protection of this invention.
[0009] Figure 1 A schematic diagram of the structure of an AR device provided in an embodiment of this application is shown.
[0010] Figure 2 A schematic diagram of another AR device provided in an embodiment of this application is shown. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on this application. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.
[0012] In the following description, references to "some embodiments" describe a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict. In the following description, the term "a plurality of" means at least two.
[0013] In the following description, the terms "first" and "second" are used merely to distinguish similar objects and do not represent a specific ordering of objects. It is understood that "first" and "second" may be interchanged in a specific order or sequence where permitted, so that the embodiments of this application described herein can be implemented in an order other than that illustrated or described herein.
[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0015] Augmented Reality (AR) technology is widely used in various fields such as gaming, education, and healthcare. AR devices provide users with an immersive experience by combining virtual information with the real world. As one of the key hardware components of AR technology, AR glasses need to possess characteristics such as lightweight design, high resolution, a large field of view (FOV), high brightness, and low power consumption to meet users' needs for wearing comfort and experience. The optical display system in AR glasses typically uses waveguide display technology, with waveguide sheets as its core component. Waveguide sheets split, guide, and output the image beam of the optomechanical display to achieve the transmission and display of virtual images.
[0016] In related technologies, an optomechanical system sends an image beam to a waveguide sheet, and a coupling region on the waveguide sheet couples out the image beam propagating within the waveguide sheet, so as to project the image beam sent by the optomechanical system in a specific direction to form a display content visible to the human eye.
[0017] However, because the coupling region is highly sensitive to ambient light, when ambient light shines on it, it disperses different wavelengths of light into rainbow beams or colored stripes, resulting in a rainbow effect. This rainbow effect not only reduces the sharpness and contrast of the image but also disrupts the immersive experience of the augmented reality system and can even cause eye strain during prolonged use, thus negatively impacting the user experience.
[0018] To address the aforementioned issues, this application provides an AR device comprising an optical engine and an optical waveguide. The optical waveguide includes a waveguide body, an entrance pupil region, and an exit pupil region. The exit pupil region includes an embossed grating and a holographic grating disposed on one side of the embossed grating, with the waveguide body disposed on the other side of the embossed grating. The optical engine is used to emit an image beam into the entrance pupil region. The holographic grating is used to increase the diffraction angle of the coupled external beam. The period of the embossed grating is greater than the period of the holographic grating.
[0019] Therefore, by combining the relief grating and the holographic grating, the external light beam is coupled out of the optical waveguide body at a larger diffraction angle, thereby reducing the amount of external light beam entering the user's field of vision, reducing the rainbow effect, and thus improving the user experience.
[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.
[0021] Please see Figure 1 , Figure 1 A schematic diagram of the structure of an AR device provided in an embodiment of this application is shown. Figure 1 As shown, the AR device 100 includes an optical engine 110 and an optical waveguide 120. The optical waveguide 120 includes an optical waveguide body 121, an entrance pupil region 122, and an exit pupil region 123. The exit pupil region 123 includes an embossed grating 1231 and a holographic grating 1232 disposed on one side of the embossed grating 1231, with the optical waveguide body 121 disposed on the other side of the embossed grating 1231.
[0022] The optomechanical system 110 is used to emit an image beam into the entrance pupil region 122; the holographic grating 1232 is used to increase the diffraction angle of the coupled external beam; and the period of the relief grating 1231 is greater than the period of the holographic grating 1232.
[0023] In some embodiments, the entrance pupil region 122 and the embossed grating 1231 can be surface embossed gratings.
[0024] In some implementations, the optical engine 110 can be a micro projector. For example, a DLP projector, an LCOS projector, and a micro light-emitting diode (MicroLED).
[0025] In other words, the propagation path of the image beam in the AR device 100 is: optical engine 110 – entrance pupil region 122 – optical waveguide body 121 – exit pupil region 123. Thus, the user can acquire the image beam along the path from the exit pupil region 123, and thereby obtain the image presented by the image beam.
[0026] The propagation path of the external light beam in the AR device 100 is: holographic grating 1232 – relief grating 1231 – optical waveguide body 121. This application uses the holographic grating 1232 to increase the diffraction angle of the external light beam after it passes through it. The increased diffraction angle then passes through the relief grating 1231, further increasing the diffraction angle. This results in the external light beam exiting the optical waveguide body 121 at a larger diffraction angle, effectively reducing the amount of light beam propagating through the optical waveguide body 121 into the user's eyes, thereby reducing the rainbow effect and improving the user experience.
[0027] Specifically, in some embodiments, the colored light formed by the diffraction of the external light beam through the holographic grating and the relief grating 1231 is at least partially deflected out of the human eye's field of vision. That is, when the external light beam passes through the relief grating 1231, due to the diffraction effect of the relief grating 1231, the external light beam is decomposed into light of different wavelengths, i.e., into light of different colors, and these different wavelengths propagate at different angles. Specific wavelengths of light will exhibit first-order or multi-order diffraction peaks at specific angles. If the diffraction angles of these different wavelengths of light exceed the acceptable angle range for the user's eyes, then the corresponding wavelength of colored light will not enter the user's field of vision, thereby ensuring that at least a portion of the colored light in the external light beam is deflected out of the human eye's field of vision, thus reducing the rainbow effect and improving the user experience.
[0028] For example, please refer to Figure 2 , Figure 2 A schematic diagram of another AR device provided in an embodiment of this application is shown. Figure 2 As shown, the user's vertical field of view is about 120°. By cooperating with the embossed grating 1231 and the holographic grating 1232, the external light beam is coupled out through the optical waveguide body 121 and does not enter the user's vertical field of view. This ensures that at least some of the colored light in the external light beam is deflected out of the human eye's field of view, thereby reducing the rainbow effect and improving the user experience.
[0029] For more details, please continue reading. Figure 2 In some embodiments, the optical waveguide body 121 includes a side surface 124 adjacent to the plane where the relief grating 1231 is located; the holographic grating 1232 is specifically used to increase the diffraction angle of the coupled target external beam, so that at least a portion of the target external beam is coupled out of the optical waveguide body 121 by the side surface 124.
[0030] The target external light beam is an external light beam with an incident angle within a preset range. In a specific embodiment, the preset range can be an external light beam with an incident angle greater than 45° relative to the exit pupil region 123. Since rainbow patterns usually originate from high-altitude and glaring light sources such as incandescent lamps and sunlight, this application sets a holographic grating 1232 in the exit pupil region 123. The relief grating 1231 and the holographic grating 1232 work together to increase the diffraction angle of the external light beam emitted by high-altitude and glaring light sources such as incandescent lamps and sunlight. This allows at least a portion of the external light beam to be coupled out of the optical waveguide body 121 from the side 124, thereby deflecting at least a portion of the colored light in the external light beam out of the field of view of the human eye, thus reducing the rainbow pattern effect and improving the user experience.
[0031] The smaller the period of the relief grating 1231 and the holographic grating 1232, the larger the diffraction angle of the external light beam after passing through the relief grating 1231 and the holographic grating 1232, and the greater the angle at which the external light beam can be coupled out of the optical waveguide body 121. Therefore, in order to enable the external light beam to be coupled out of the optical waveguide body 121 at the largest possible angle, in some embodiments, the period of the relief grating 1231 is greater than the period of the holographic grating 1232. Structurally, this is manifested as follows: the relief grating 1231 includes a plurality of first grating lines, and the holographic grating 1232 includes a plurality of second grating lines; the sum of the spacing between adjacent first grating lines and the width of any one of the first grating lines is X1; the sum of the spacing between adjacent second grating lines and the width of any one of the second grating lines is X2; wherein X2 is less than X1.
[0032] By making the period of the relief grating 1231 greater than the period of the holographic grating 1232, the image beam emitted by the optical engine 110 will not be coupled out of the optical waveguide body 121 with a large diffraction angle, thereby avoiding reducing the user's acquisition of the image beam emitted by the optical engine 110.
[0033] By setting the period of the holographic grating 1232 to be smaller, the diffraction angle of the external light beam can be effectively increased. The diffraction angle of the external light beam can be further increased by the relief grating 1231, so that the external light beam is coupled out of the optical waveguide body 121 with a larger diffraction angle, thereby reducing the amount of external light beam received by the user.
[0034] In some embodiments, the holographic grating 1232 includes a plurality of second grating lines, which are arranged sequentially along the length of the optical waveguide body 121. From one end of the holographic grating 1232 to the other end, the spacing between different adjacent second grating lines gradually decreases, forming a decreasing pattern.
[0035] In other words, the gradual refractive index setting of the holographic grating 1232 reduces the brightness of the incident external light beam after transmission by adjusting the refractive index of the holographic grating 1232, thereby effectively weakening the intensity of the transmitted light and reducing the impact of the external light beam on the imaging effect of the AR device 100.
[0036] The exit pupil region includes relief gratings and holographic gratings with different grating directions. Setting different holographic grating directions deflects the diffraction angle of external light beams away from the direction of the human eye. When external light shines on the holographic grating, the diffraction angle changes with the holographic grating direction. By setting different grating directions, external light is deflected to a position invisible to the human eye in different structures. Furthermore, the holographic grating itself has diffraction energy asymmetry. That is, setting different grating parameters, such as period and duty cycle, can make the energy of the diffraction order (such as 0th order and 1st order diffraction) of the holographic grating different, thereby reducing the energy of the order of external light diffracted that might be deflected to the human eye, reducing stray light seen by the human eye.
[0037] In one specific embodiment, the holographic grating 1232 can be made of holographic materials, which may include photosensitive materials, optical recording materials, volume holographic materials, liquid crystal materials, and novel composite materials.
[0038] Among these, photosensitive materials can be silver halide emulsions and photosensitive polymers. Optical recording materials can be photorefractive crystals and photochromic materials. Volume holographic materials can be polymer-dispersed liquid crystals and optical glasses. Novel holographic materials can be nanocomposite materials, quantum dot materials, and two-dimensional materials.
[0039] A holographic grating 1232 can be formed on the grating 1231 by setting an embossed grating 1231 on the optical waveguide body 121, then spin-coating holographic material on the embossed grating 1231, and then exposing the holographic material by irradiating it with two beams of coherent light.
[0040] In order to better increase the diffraction angle of the external light beam so that the external light beam is coupled out of the optical waveguide body 121 at a larger diffraction angle, in some embodiments, the projection of the holographic grating 1232 onto the relief grating 1231 at least covers the central region of the relief grating 1231.
[0041] The central region includes the midpoint of the relief grating 1231, and occupies more than 40% of the area of the relief grating 1231. By aligning the relief grating 1231 with the holographic grating 1232, all external light beams reaching the relief grating 1231 pass through the holographic grating 1232, thereby achieving mutual cooperation between the relief grating 1231 and the holographic grating 1232, and thus enabling the external light beams to be coupled out of the optical waveguide body 121 at a larger angle.
[0042] In some embodiments, the AR device 100 includes two exit pupil regions 123, which are respectively disposed on both sides of the entrance pupil region 122. The two exit pupil regions 123 respectively couple the image beam that is coupled into the optical waveguide body 121 by the entrance pupil region 122 and out of the optical waveguide body 121, so that the user can acquire the image beam along the path of the image beam coupled out of the two exit pupil regions 123, thereby acquiring the image corresponding to the image beam.
[0043] Both exit pupil regions 123 include an embossed grating 1231 and a holographic grating 1232.
[0044] To further enhance the image beams coupled from the two exit pupil regions 123, in some embodiments, the AR device includes a refractive region for propagating at least a portion of the image beam coupled from the entrance pupil region to the exit pupil region 123.
[0045] In other words, the image beam emitted by the optical engine 110 is coupled into the optical waveguide body 121 through the entrance pupil region 122, then propagates to the refraction region, and then propagates to the exit pupil region 123 through the refraction region.
[0046] In one specific embodiment, the AR device 100 includes two refractive regions for propagating at least a portion of an image beam coupled into the entrance pupil region to the two exit pupil regions.
[0047] The two refractive regions are respectively located on both sides of the entrance pupil region 122. The two refractive regions can be surface-embossed gratings. In another embodiment, the two refractive regions can be embossed gratings.
[0048] The entrance pupil region 122, the two exit pupil regions 123, and the two refractive regions can be disposed on the same surface of the optical waveguide body 121. Some of these regions can be disposed on one surface of the optical waveguide body 121, while others can be disposed on the other surface. In other words, this application does not impose any restrictions on whether the entrance pupil region 122, the two exit pupil regions 123, and the two refractive regions are disposed on the same surface of the optical waveguide body 121; they can be flexibly configured according to actual conditions.
[0049] In some embodiments, the entrance pupil region 122 is one of a holographic grating and an embossed grating.
[0050] This application provides an AR device, comprising: an optical engine and an optical waveguide; the optical waveguide includes a waveguide body, an entrance pupil region, and an exit pupil region; the exit pupil region includes an embossed grating and a holographic grating disposed on one side of the embossed grating, and the optical waveguide body disposed on the other side of the embossed grating; the optical engine is used to emit an image beam into the entrance pupil region; the holographic grating is used to increase the diffraction angle of the coupled external beam; the period of the embossed grating is greater than the period of the holographic grating. Thus, by the cooperation of the embossed grating and the holographic grating, the external beam is coupled out of the optical waveguide body with a larger diffraction angle, thereby reducing the amount of external beam entering the user's field of vision, reducing the rainbow effect, and improving the user experience.
[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. An AR device, characterized in that, The AR device includes an optical engine and an optical waveguide; The optical waveguide includes an optical waveguide body, an entrance pupil region, and an exit pupil region; The exit pupil region includes an embossed grating and a holographic grating disposed on one side of the embossed grating, and the optical waveguide body is disposed on the other side of the embossed grating; The optical engine is used to emit an image beam toward the entrance pupil region; The holographic grating is used to increase the diffraction angle of the coupled external light beam; The period of the relief grating is greater than the period of the holographic grating.
2. The AR device according to claim 1, characterized in that, The colored light formed by the external light beam after being diffracted by the holographic grating and the relief grating is at least partially deviated from the field of view of the human eye.
3. The AR device according to claim 1, characterized in that, The optical waveguide body includes a side surface adjacent to the plane where the relief grating is located; The holographic grating is specifically used to increase the diffraction angle of the coupled target external beam, which is the external beam with an incident angle within a preset range, so that at least a portion of the target external beam is coupled out of the optical waveguide body from the side.
4. The AR device according to claim 1, characterized in that, The holographic grating includes a plurality of second grating lines, which are arranged sequentially along the length of the optical waveguide body. From one end of the holographic grating to the other end, the spacing between different adjacent second grating lines gradually decreases, forming a decreasing pattern.
5. The AR device according to claim 1, characterized in that, The projection of the holographic grating onto the relief grating covers at least the central area of the relief grating.
6. The AR device according to claim 1, characterized in that, The AR device includes a refractive region for propagating at least a portion of the image beam coupled into the entrance pupil region toward the exit pupil region.
7. The AR device according to claim 1, characterized in that, The AR device includes two exit pupil regions, which are respectively located on both sides of the entrance pupil region.
8. The AR device according to claim 7, characterized in that, The AR device includes two refractive regions for propagating at least a portion of the image beam coupled into the entrance pupil region to the two exit pupil regions.
9. The AR device according to claim 1, characterized in that, The exit pupil region includes relief gratings and holographic gratings with different directions. Setting different holographic grating directions will diffract the diffraction angle of the external light beam away from the direction of the human eye.