Ar device and optical waveguide

Abstract

This application discloses an AR device and an optical waveguide. The AR device includes an optical engine and an optical waveguide. The optical waveguide includes an entrance pupil region, a dilated pupil region, and an exit pupil region. The optical engine is used to emit an image beam into the entrance pupil region. The distance between the optical engine and the entrance pupil region is less than or equal to the focal length of the optical engine. Therefore, by making the distance between the optical engine and the entrance pupil region less than the focal length of the optical engine, the image beam emitted by the optical engine intersects within the optical waveguide, reducing the propagation area of ​​the image beam within the optical waveguide. This allows the area corresponding to the dilated pupil region to be set smaller, thereby reducing the area of ​​the optical waveguide and thus reducing the manufacturing material cost of the AR device.

Description

Technical Field

[0001] This application relates to the technical field of AR devices, and more specifically, to an AR device and an optical waveguide. 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. Among them, the diffractive waveguide is a key component of AR devices. The diffractive waveguide uses grating diffraction to guide the propagation direction of the image beam and expand the propagation range of the image beam, so as to deliver the image beam to the user's eyes and form an image in the user's eyeball.

[0003] In related technologies, a diffractive waveguide includes independently configured entrance pupil, expansion pupil, and exit pupil regions. The entrance pupil is the entry point into the diffractive waveguide where the image beam from the optomechanical display is coupled; the expansion pupil guides the propagation direction of the image beam within the diffractive waveguide to the exit pupil region; and the exit pupil couples the image beam out of the diffractive waveguide to transmit the image beam to the user's eye, thereby forming an image within the user's eyeball.

[0004] To ensure that the image beam coupled to the entrance pupil region can fully propagate to the exit pupil region, the only solution is to increase the pupil area. However, a larger pupil area results in a larger diffraction waveguide area, thus increasing the cost of materials used in the manufacture of AR devices. Summary of the Invention

[0005] In view of the above problems, this application proposes an AR device and an optical waveguide that can effectively reduce the area corresponding to the pupil expansion region, thereby reducing the cost of manufacturing materials for the AR device.

[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 entrance pupil region, a dilated pupil region, and an exit pupil region; the optical engine is used to emit an image beam toward the entrance pupil region; the distance between the optical engine and the entrance pupil region is less than or equal to the focal length of the optical engine.

[0007] Secondly, embodiments of this application also provide an optical waveguide, which includes an entrance pupil region, a dilation pupil region, and an exit pupil region, wherein the width of the dilation pupil region increases from the middle of the dilation pupil region to both ends along the length direction of the dilation pupil region.

[0008] The technical solution provided in this application includes an AR device comprising: an optical engine and an optical waveguide; the optical waveguide includes an entrance pupil region, a dilated pupil region, and an exit pupil region; the optical engine is used to emit an image beam into the entrance pupil region; the distance between the optical engine and the entrance pupil region is less than the focal length of the optical engine. Therefore, by ensuring that the distance between the optical engine and the entrance pupil region is less than or equal to the focal length of the optical engine, the image beam emitted by the optical engine intersects within the optical waveguide, thereby reducing the propagation area of ​​the image beam within the optical waveguide. This allows the area corresponding to the dilated pupil region to be set smaller, thus reducing the area of ​​the optical waveguide and consequently reducing the manufacturing material cost of the AR device. Attached Figure Description

[0009] 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.

[0010] Figure 1 A schematic diagram of the structure of an AR device provided in an embodiment of this application is shown.

[0011] Figure 2 A schematic diagram of an optical waveguide provided in an embodiment of this application is shown.

[0012] Figure 3 A schematic diagram of the structure of an image beam provided in an embodiment of this application is shown.

[0013] Figure 4 A schematic diagram of an image beam propagation path provided in an embodiment of this application is shown.

[0014] Figure 5 A schematic diagram of the structure of another AR device provided in an embodiment of this application is shown.

[0015] Figure 6 A schematic diagram of another image beam propagation path provided in an embodiment of this application is shown.

[0016] Figure 7 A schematic diagram of another optical waveguide provided in an embodiment of this application is shown.

[0017] Figure 8 A schematic diagram of the structure of another AR device provided in an embodiment of this application is shown.

[0018] Figure 9 A schematic flowchart of a distance adjustment method provided in an embodiment of this application is shown.

[0019] Figure 10 A schematic diagram of a distance adjustment device provided in an embodiment of this application is shown.

[0020] Figure 11 A schematic diagram of the structure of an AR device provided in an embodiment of this application is shown.

[0021] Figure 12 This illustration shows a schematic diagram of the structure of a computer-readable storage medium provided in an embodiment of this application. Detailed Implementation

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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. Among them, the diffractive waveguide is a key component of AR devices. The diffractive waveguide uses grating diffraction to guide the propagation direction of the image beam and expand the propagation range of the image beam, so as to deliver the image beam to the user's eyes and form an image in the user's eyeball.

[0027] In related technologies, a diffractive waveguide includes independently configured entrance pupil, expansion pupil, and exit pupil regions. The entrance pupil is the entry point into the diffractive waveguide where the image beam from the optomechanical display is coupled; the expansion pupil guides the propagation direction of the image beam within the diffractive waveguide to the exit pupil region; and the exit pupil couples the image beam out of the diffractive waveguide to transmit the image beam to the user's eye, thereby forming an image within the user's eyeball.

[0028] Increasing the area of ​​the pupil expansion region allows the image beam coupled into the entrance pupil region to reach the exit pupil region more effectively. However, the larger area of ​​the pupil expansion region also results in a larger area of ​​the diffraction waveguide, thereby increasing the cost of materials used in the manufacture of AR devices.

[0029] To address the aforementioned issues, this application provides an AR device and an optical waveguide. The AR device includes an optical engine and an optical waveguide. The optical waveguide includes an entrance pupil region, a dilated pupil region, and an exit pupil region. The optical engine is used to emit an image beam into the entrance pupil region. The distance between the optical engine and the entrance pupil region is less than the focal length of the optical engine.

[0030] Therefore, by making the distance between the optical engine and the entrance pupil region smaller than the focal length of the optical engine, the image beam emitted by the optical engine has an intersection region within the optical waveguide, thereby reducing the propagation area of ​​the image beam within the optical waveguide. This allows the area corresponding to the expanded pupil region to be set smaller, thereby reducing the area of ​​the optical waveguide and thus reducing the cost of manufacturing materials for AR devices.

[0031] 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.

[0032] Please see Figure 1 as well as Figure 2 , Figure 1 This paper shows a schematic diagram of the structure of an AR device provided in an embodiment of this application. Figure 2 A schematic diagram of an optical waveguide structure provided in an embodiment of this application is shown. Figure 1 and Figure 2 As shown, the AR device 100 includes an optical engine 1 and an optical waveguide 2. The optical waveguide 2 includes an entrance pupil region 21, a dilated pupil region 22, and an exit pupil region 23. The distance between the optical engine 1 and the entrance pupil region 21 is less than the focal length of the optical engine 1. The optical engine 1 is used to emit an image beam towards the entrance pupil region 21.

[0033] The entrance pupil region 21 couples the image beam into the entrance of the optical waveguide 2; the expanding pupil region 22 allows the image beam to propagate in a certain direction within the optical waveguide 2, thereby increasing the size of the exit pupil region 23 and thus improving the field of view of the AR device 100. The exit pupil region 23 releases the image beam from the optical waveguide 2 and transmits it to the exit of the user's eye, directly affecting the display effect seen by the user.

[0034] The entrance pupil region 21, the dilation pupil region 22, and the exit pupil region 23 are usually set independently, and structures in which the entrance pupil region 21, the dilation pupil region 22, and the exit pupil region 23 completely overlap are rare. By setting the entrance pupil region 21, the dilation pupil region 22, and the exit pupil region 23 independently, it is ensured that the function of each region is not interfered with.

[0035] In other words, when the optical engine 1 is in the light-emitting state, the optical engine 1 emits an image beam into the optical waveguide 2 through the entrance pupil region 21. The image beam propagates inside the optical waveguide 2 and is emitted by the optical engine 1 to the exit pupil region 23 through the pupil expansion region 22. The image beam then propagates to the user's eye through the exit pupil region 23, so that the user can obtain the corresponding content played by the optical engine 1.

[0036] In some embodiments, the optical engine 1 can be a micro projector. In some embodiments, the optical engine 1 includes one of a DLP projector, an LCOS projector, and a micro light-emitting diode (MicroLED).

[0037] In some embodiments, the entrance pupil region 21 and the exit pupil region 23 include one of a grating or a beam splitter. Whether the entrance pupil region 21 and the exit pupil region 23 are gratings or beam splitters is determined according to the specific circumstances of the optical waveguide 2. For example, when the optical waveguide 2 is a diffractive waveguide, the entrance pupil region 21 and the exit pupil region 23 are gratings (e.g., surface-embossed gratings).

[0038] When the optical engine 1 emits an image beam that reaches the entrance pupil region 21, it is coupled into the optical waveguide 2 after passing through the entrance pupil region 21. The distance between the optical engine 1 and the entrance pupil region 21 at this time is called the coupling distance. The coupling distance between the optical engine 1 and the entrance pupil region 21 includes negative distance coupling, positive distance coupling, and zero distance coupling.

[0039] Specifically, the image beam emitted by the optical engine 1 first contracts to a single point, and then expands from that point. When the image beam is emitted from the optical engine 1 and is in a contracted state, the coupling distance between the optical engine 1 and the entrance pupil region 21 is called negative distance coupling. That is, the distance from when the image beam is emitted from the optical engine 1 to before the image beam contracts to a single point is defined as negative distance coupling.

[0040] The distance between the image beam emitted from optical engine 1 and the point where the image beam contracts into a single point is defined as zero-distance coupling. The distance after the image beam spreads out from a single point is defined as positive-distance coupling.

[0041] In some implementations, the coupling distance between the optical engine 1 and the entrance pupil region 21 when there is zero-distance coupling can be determined based on the focal length of the optical engine 1. In other words, the focal length of the optical engine 1 is the coupling distance corresponding to zero-distance coupling.

[0042] The distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1. The light source corresponding to the image beam emitted by the optical engine 1 into the entrance pupil region 21 can be equivalent to two symmetrically distributed sub-light sources, thereby forming a complete field of view in the entrance pupil region 21. For example, the angle of the left image beam is -20°, and the angle of the right image beam is 20°. The two together constitute a 40° field of view.

[0043] For example, numerous -20° image beams are emitted by optical engine 1, and numerous 20° image beams are emitted by optical engine 1, with an angle of 40° between these image beams, thus forming a 40° field of view. Please refer to... Figure 3 , Figure 3 A schematic diagram of the structure of an image beam provided in an embodiment of this application is shown. Figure 3 Taking only two image beams as an example, the left image beam has an angle of -20° and the right image beam has an angle of 20°. Together, they form a 40° field of view. It is understood that the optical engine 1 can also emit image beams at other angles to form a field of view at other angles. This application does not limit the angle of the image beams.

[0044] The area of ​​the entrance pupil region 21 is related to the area of ​​the light spot formed by the image beam emitted by the optical engine 1 into the entrance pupil region 21. The area of ​​the dilation pupil region 22 is related to the area of ​​the entrance pupil region 21. That is, the larger the area of ​​the entrance pupil region 21, the larger the area of ​​the dilation pupil region 22. This is so that the dilation pupil region 22 can propagate the image beam propagating from the entrance pupil region 21 to the exit pupil region 23 to the maximum extent, so as to avoid some of the image beam propagating from the entrance pupil region 21 failing to reach the dilation pupil region 22 and causing waste.

[0045] In some embodiments, the shape of the pupil expansion region 22 is the same as the shape of the image beam propagation region within the optical waveguide 2. This is to ensure that the image beam within the optical waveguide 2 hits the pupil expansion region 22 as much as possible, and then propagates through the pupil expansion region 22 to the exit pupil region 23, thereby avoiding waste of the image beam.

[0046] As described above, because the distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1, the image beams emitted by the two sub-light sources intersect, resulting in a smaller spot size of the image beams in the entrance pupil region 21. For details, please refer to... Figure 3 and Figure 4 , Figure 3 This paper illustrates a schematic diagram of another AR device provided in an embodiment of the present application. Figure 4 A schematic diagram of an image beam propagation path provided in an embodiment of this application is shown. For example... Figure 3 and Figure 4 As shown, Figure 4 A means that the distance between the optical engine 1 and the entrance pupil region 21 is greater than the focal length of the optical engine 1, that is, the coupling distance between the optical engine 1 and the entrance pupil region 21 is positive distance coupling, and there is no intersection of the image beams. This results in a larger propagation area of ​​the image beams within the optical waveguide 2, thus requiring a larger pupil expansion region 22. Figure 4 B is when the distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1, and the image beams intersect, resulting in a smaller propagation area of ​​the image beams within the optical waveguide 2, thus requiring a smaller pupil region 22.

[0047] For more details, please continue reading. Figure 4 The pupil dilation region 22 presents a trapezoidal structure, assuming Figure 4 In region A, the length of the upper base of the pupil-dilation region 22 is 2d, and the length of the lower base of the pupil-dilation region 22 is b. Then... Figure 4 The area of ​​the dilated pupil region 22 in A is (b / (2d+b)). 100%. Assuming b is 10mm and 2d is 5mm, then we can determine... Figure 4 The area of ​​the dilated pupil region 22 in A is 66.6%. And... Figure 4 In B, Figure 4 The upper base side length of the pupil expansion region 22 in B can be designed as d based on the diameter of the sub-light source. In other words, Figure 4 The pupillary dilation area 22 in B is relative to Figure 4 The area of ​​the pupil expansion region 22 in A can be reduced by approximately 34%.

[0048] By controlling the distance between the optical engine 1 and the entrance pupil region 21 to be less than or equal to the focal length of the optical engine 1, the image beam emitted by the optical engine 1 intersects within the optical waveguide 2, thus reducing the propagation range of the image beam within the optical waveguide 2. Consequently, the area of ​​the expanded pupil region 22 can be correspondingly reduced. Simultaneously, while reducing the area of ​​the expanded pupil region 22, it is still possible to effectively prevent some image beams propagating from the entrance pupil region 21 from failing to reach the expanded pupil region 22, thus avoiding waste.

[0049] Furthermore, since the focal length of the optical engine 1 is generally small (e.g., the focal length of the optical engine 1 is 1mm), in order to ensure that the distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1, in a specific embodiment, please refer to... Figure 5 , Figure 5 A schematic diagram of the structure of another AR device provided in an embodiment of this application is shown. Figure 5 As shown, the light-emitting side of the optical engine 1 is attached to the entrance pupil region 21.

[0050] By attaching the light-emitting side of the optical engine 1 to the entrance pupil region 21, the distance between the optical engine 1 and the entrance pupil region 21 is kept small, so that the distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1. This causes the image beam to cross within the optical waveguide 2, thus reducing the propagation range of the image beam within the optical waveguide 2. Consequently, the area of ​​the expanded pupil region 22 can be set to a smaller area, thereby reducing the area of ​​the optical waveguide 2 and reducing the cost of the materials used to manufacture the optical waveguide 2.

[0051] Assuming that eight optical waveguides 2 can be imprinted on a single wafer, by reducing the area of ​​the pupil expansion region 22, the area corresponding to one optical waveguide 2 can be reduced, thereby allowing three to four more optical waveguides 2 to be imprinted on a single wafer of the same size, thus saving on the production cost of AR devices.

[0052] However, when the light-emitting side of the optical engine 1 is attached to the entrance pupil region 21, the image beam will be reflected inside the optical engine 1, producing ghosting. Ghosting will affect the imaging effect of the AR device, thereby affecting the user experience. To avoid the above situation, in some embodiments, the central axis of the optical engine 1 is tilted to the surface of the entrance pupil region 21.

[0053] In some embodiments, the angle between the optical engine 1 and the entrance pupil region 21 is an acute angle. By tilting the surfaces of the optical engine 1 and the entrance pupil region 21, ghosting is removed from the image, thereby avoiding the impact of ghosting on the imaging effect of the AR device and improving the user experience.

[0054] By fitting the optical engine 1 to the entrance pupil region 21 and tilting them together, the distance between the optical engine 1 and the entrance pupil region 21 is ensured to be less than or equal to the focal length of the optical engine 1. This improves imaging performance while effectively reducing the area of ​​the enlarged pupil region 22. However, because the light-emitting side of the optical engine 1 is fitted to the entrance pupil region 21, they are prone to interference.

[0055] For example, the optical engine 1 and the entrance pupil region 21 are prone to mutual friction, causing wear and tear on both, which may affect the imaging performance of the AR device. It's even possible that friction between the optical engine 1 and the entrance pupil region 21 could cause misalignment of the optical engine 1. This could result in the distance between the optical engine 1 and the entrance pupil region 21 exceeding the focal length of the optical engine 1, causing a portion of the image beam emitted by the optical engine 1 to miss the entrance pupil region 21, resulting in wasted light and potentially affecting the imaging performance of the AR device.

[0056] Based on the above, in some embodiments, the focal length of the optical engine 1 is greater than 1 mm. By increasing the focal length of the optical engine 1, the distance between the optical engine 1 and the entrance pupil region 21 is increased. That is, it is not necessary for the optical engine 1 and the entrance pupil region 21 to be fitted together, and the distance between the optical engine 1 and the entrance pupil region 21 can be less than or equal to the focal length of the optical engine 1.

[0057] By adjusting the focal length of the optical engine 1, even when the distance between the optical engine 1 and the entrance pupil region 21 is relatively large, the coupling distance between the optical engine 1 and the entrance pupil region 21 remains negative distance coupling. This avoids mutual interference between the optical engine 1 and the entrance pupil region 21. It also prevents misalignment of the optical engine 1 due to friction between the two regions.

[0058] In one specific embodiment, the optical engine 1 includes a front lens group. The front lens group may include multiple lenses. The focal length of the optical engine 1 is adjusted by adjusting the exit pupil distance (i.e., focal length) of the outermost convex lens of the front lens group.

[0059] The exit pupil distance of a convex lens is related to its radius of curvature. Generally, the larger the radius of curvature of a convex lens, the larger its focal length. In extreme cases, a convex lens can be a flat plate lens.

[0060] Specifically, the exit pupil distance of a convex lens can be adjusted by its refractive index and the radii of curvature on both sides. In other words, the exit pupil distance of a convex lens is related to its refractive index and the radii of curvature on both sides, and this relationship can be expressed by the following formula:

[0061] f ;

[0062] Where f is the exit pupil distance of the convex lens; n is the refractive index of the convex lens; and R1 and R2 are the radii of curvature on both sides of the convex lens.

[0063] Users can determine the specific values ​​of the radii of curvature on both sides to make the exit pupil distance of the convex lens equal to the target value, for example, to make the exit pupil distance of the convex lens 1.5mm, 2mm, or 2.2mm, etc.

[0064] By adjusting the radius of curvature of the convex lens, the focal length of the optical engine 1 can be adjusted, thereby achieving a distance between the optical engine 1 and the entrance pupil region 21 that is less than or equal to the focal length of the optical engine 1 without requiring them to be fitted together.

[0065] When the distance between the optical engine 1 and the entrance pupil region 21 is less than or equal to the focal length of the optical engine 1, the light source corresponding to the image beam emitted by the optical engine 1 into the entrance pupil region 21 can be equivalent to two symmetrically distributed sub-light sources, and the positional relationship between the two sub-light sources is tangent. For details, please refer to... Figure 6 as well as Figure 7 , Figure 6 This invention provides a schematic diagram of another image beam propagation path according to an embodiment of the present application. Figure 7 A schematic diagram of another optical waveguide structure provided in an embodiment of this application is shown. For example... Figure 6 as well as Figure 7 As shown, the image beam propagates in a butterfly shape within the optical waveguide 2 through the entrance pupil region 21. The area of ​​the dilated pupil region 22 can be set according to the propagation area of ​​the image beam within the optical waveguide 2. That is, the width of the dilated pupil region 22 increases from the middle of the dilated pupil region 22 to both ends along the length direction of the dilated pupil region 22.

[0066] By setting the pupil expansion region 22 to a butterfly shape, the area of ​​the pupil expansion region 22 can be further reduced, thereby further reducing the area of ​​the optical waveguide 2.

[0067] In one specific embodiment, please refer to Figure 8 , Figure 8 A schematic diagram of another AR device provided in an embodiment of this application is shown. Figure 8 As shown, the optical waveguide 2 includes two pupil expansion regions 22 and two exit pupil regions 23. The two pupil expansion regions 22 and the two exit pupil regions 23 have a one-to-one correspondence. That is, the left pupil expansion region 22 is used to propagate the image beam entering the optical waveguide 2 through the entrance pupil region 21 to the left exit pupil region 23. The right pupil expansion region 22 is used to propagate the image beam entering the optical waveguide 2 through the entrance pupil region 21 to the right exit pupil region 23.

[0068] Furthermore, such as Figure 8 As shown, two pupil expansion regions 22 and two exit pupil regions 23 are symmetrically arranged on both sides of the entrance pupil region 21. It can be understood that the specific structure of the above-mentioned optical engine 1 and optical waveguide 2 can also be used in the waveguide architecture of a single eye.

[0069] In one embodiment, the entrance pupil region 21, the two dilated pupil regions 22, and the two exit pupil regions 23 are disposed on the same side of the optical waveguide 2, that is, the entrance pupil region 21, the two dilated pupil regions 22, and the two exit pupil regions 23 are disposed on the same surface of the optical waveguide 2. In another embodiment, the entrance pupil region 21, the two dilated pupil regions 22, and the two exit pupil regions 23 are respectively disposed on opposite surfaces of the optical waveguide 2. That is, the entrance pupil region 21, the two dilated pupil regions 22, and the two exit pupil regions 23 can be disposed on two opposite sides of the optical waveguide 2. In other words, the entrance pupil region 21, the two dilated pupil regions 22, and the two exit pupil regions 23 do not need to be disposed on the same side.

[0070] For example, the optical waveguide 2 includes a first surface and a second surface disposed opposite to each other, with an entrance pupil region 21 disposed on the first surface, and two expanding pupil regions 22 and two exit pupil regions 23 disposed on the second surface. Alternatively, the entrance pupil region 21 may be disposed on the second surface, and the two expanding pupil regions 22 and two exit pupil regions 23 may be disposed on the first surface. Or, the two expanding pupil regions 22 may be disposed on the first surface, and the entrance pupil region 21 and the two exit pupil regions 23 may be disposed on the second surface.

[0071] The specific structure of the aforementioned optical engine 1 and optical waveguide 2 can be applied to head-mounted display devices (AR / VR). By utilizing the specific structure of the optical engine 1 and optical waveguide 2 provided in this application, and by ensuring that the distance between the optical engine 1 and optical waveguide 2 is less than or equal to the focal length of the optical engine 1, the optical waveguide 2 of the head-mounted display device (AR / VR) can be made more compact, which helps to reduce the overall weight of the display device (AR / VR) and improve the user's wearing comfort and user experience.

[0072] The specific structures of the aforementioned optical engine 1 and optical waveguide 2 can also be applied to smart glasses. Utilizing the specific structures of the optical engine 1 and optical waveguide 2 provided in this application, and the fact that the distance between the optical engine 1 and optical waveguide 2 is less than or equal to the focal length of the optical engine 1, the optical waveguide 2 can be more easily integrated into the lenses of smart glasses. This improves the wearability and aesthetics of smart glasses, making them suitable for prolonged use without affecting visual performance.

[0073] The specific structure of the aforementioned optical engine 1 and optical waveguide 2 can also be applied to automotive head-up display (HUD) systems. By utilizing the specific structure of the optical engine 1 and optical waveguide 2 provided in this application, and by ensuring that the distance between the optical engine 1 and optical waveguide 2 is less than or equal to the focal length of the optical engine 1, the area of ​​the optical waveguide 2 can be reduced, thereby reducing the space occupied by the automotive head-up display system in the dashboard, making it easier to integrate, and optimizing the interior design of the vehicle.

[0074] The specific structures of the aforementioned optical engine 1 and optical waveguide 2 can also be applied to optical display modules, such as projectors and microdisplays. By utilizing the specific structures of the optical engine 1 and optical waveguide 2 provided in this application, and ensuring that the distance between the optical engine 1 and optical waveguide 2 is less than or equal to the focal length of the optical engine 1, the internal space of the optical display module is saved by reducing the area of ​​the pupil expansion region 22 and the overall area of ​​the optical waveguide 2, providing a more compact and efficient optical transmission solution.

[0075] The specific structures of the aforementioned optical engine 1 and optical waveguide 2 can also be applied to industrial-grade optical systems. By utilizing the specific structures of the optical engine 1 and optical waveguide 2 provided in this application, and by ensuring that the distance between the optical engine 1 and optical waveguide 2 is less than or equal to the focal length of the optical engine 1, the efficiency of optical transmission 2 can be improved, the distance requirements between optical components can be reduced, and the size of the corresponding equipment in the industrial-grade optical system can be reduced.

[0076] Please see Figure 9 , Figure 9 A flowchart illustrating a distance adjustment method provided in an embodiment of this application is shown. Figure 9 As shown, this distance adjustment method is applied to the aforementioned AR device. The distance adjustment method includes steps 210 to 230, specifically:

[0077] In step 210, the ideal distance between the optomechanical system and the optical waveguide is determined.

[0078] In step 220, the focal length of the optical engine is adjusted according to the ideal distance.

[0079] In step 230, the actual distance between the optical engine and the optical waveguide is adjusted according to the focal length of the optical engine, so that the optical engine and the optical waveguide are negative distance coupled.

[0080] To avoid friction between the optical engine and the waveguide, which could cause wear or misalignment, the focal length of the optical engine can be adjusted to allow for negative distance coupling, preventing them from being directly attached to each other.

[0081] The ideal distance can be determined based on the overall settings of the AR device. For example, the ideal distance could be around 2mm. Alternatively, it could be 1.5mm, 2mm, or 2.2mm, etc.

[0082] The focal length of an optical engine is related to the radius of curvature of a convex lens. By adjusting the specific value of the radius of curvature of the convex lens, the focal length of the optical engine can be adjusted. Given an ideal distance between the optical engine and the optical waveguide, the radius of curvature of the convex lens corresponding to the ideal distance can be determined using a preset table. Then, based on the determined radius of curvature of the convex lens, the corresponding convex lens can be installed on the optical engine.

[0083] The preset table includes the exit pupil distance (focal length) corresponding to different radii of curvature of the convex lens.

[0084] After adjusting the convex lens on the optical engine, the actual distance between the optical engine and the optical waveguide is adjusted according to the current focal length of the optical engine. This ensures that the actual distance between the optical engine and the optical waveguide is less than or equal to the focal length of the optical engine, thereby achieving negative distance coupling between the optical engine and the optical waveguide. This allows the image beam emitted by the optical engine to cross within the optical waveguide, reducing the propagation area of ​​the image beam within the optical waveguide. Based on the propagation area of ​​the image beam within the optical waveguide, a smaller pupil expansion area is determined, allowing the pupil area on the optical waveguide of the AR device to be set smaller, thus reducing the manufacturing cost of the AR device.

[0085] Those skilled in the art will understand that, for the sake of convenience and brevity, the corresponding processes in the foregoing structural embodiments can be referred to, and will not be repeated here.

[0086] Please see Figure 10 , Figure 10 This illustration shows a schematic diagram of a distance adjustment device 300 provided in an embodiment of this application. The distance adjustment device 300 includes: a first determining module 310, a second determining module 320, and an adjusting module 330. Specifically:

[0087] The first determining module 310 is used to determine the ideal distance between the optomechanical system and the optical waveguide.

[0088] The second determining module 320 is used to adjust the focal length of the optical engine according to the ideal distance.

[0089] The adjustment module 330 is used to adjust the actual distance between the optical engine and the optical waveguide according to the focal length of the optical engine, so that the optical engine and the optical waveguide are negative distance coupled.

[0090] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0091] In the several embodiments provided in this application, the coupling or direct coupling or communication connection between the modules shown or discussed may be an indirect coupling or communication connection through some interface, device or module, and may be electrical, mechanical or other forms.

[0092] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules.

[0093] Please see Figure 11 , Figure 11 The diagram shows a structural schematic of an AR device provided in an embodiment of this application. The terminal device 400 in this application may include one or more of the following components: a processor 410, a memory 420, and one or more applications. The one or more applications may be stored in the memory 420 and configured to be executed by one or more processors 410. The one or more applications are configured to perform the distance adjustment method as described in the foregoing method embodiments.

[0094] Processor 410 may include one or more processing cores. Processor 410 connects to various parts of the terminal device 400 using various interfaces and lines, and performs various functions and processes data of the terminal device 400 by running or executing instructions, programs, code sets, or instruction sets stored in memory 420, and by calling data stored in memory 420. Optionally, processor 410 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). Processor 410 may integrate one or a combination of several of the following: Central Processing Unit (CPU), Graphics Processing Unit (GPU), and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into processor 410 and may be implemented separately using a communication chip.

[0095] The memory 420 may include random access memory (RAM) or read-only memory (ROM). The memory 420 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 420 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function, instructions for implementing the various method embodiments described below, etc. The data storage area may also store data created by the terminal device 400 during use.

[0096] Please see Figure 12 , Figure 12 The diagram shows a computer-readable storage medium 500 provided in an embodiment of this application. The computer-readable storage medium 500 stores program code, which can be called by a processor to execute the cooking control method described in the above method embodiment.

[0097] The computer-readable storage medium 500 may be an electronic memory such as flash memory, EEPROM (Electrically Erasable Programmable Read-Only Memory), EPROM, hard disk, or ROM. Optionally, the computer-readable storage medium 400 includes a non-transitory computer-readable storage medium. The computer-readable storage medium 500 has storage space for program code 510 that performs any of the method steps described above. This program code can be read from or written to one or more computer program devices. The program code 510 may, for example, be compressed in a suitable form.

[0098] 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 is a diffractive optical waveguide, and the optical waveguide includes an entrance pupil region, a pupil expansion region, and an exit pupil region; The optical engine is used to emit an image beam toward the entrance pupil region; The distance between the optical engine and the entrance pupil region is less than or equal to the focal length of the optical engine, such that the image beam emitted by the optical engine intersects within the optical waveguide; The shape of the pupil expansion region is the same as the shape of the propagation region of the image beam within the optical waveguide.

2. The AR device according to claim 1, characterized in that, The light-emitting side of the optical engine is attached to the entrance pupil region.

3. The AR device according to claim 2, characterized in that, The central axis of the optical engine is inclined to the surface of the entrance pupil region.

4. The AR device according to claim 1, characterized in that, The optical waveguide includes two pupil expansion regions and two exit pupil regions.

5. The AR device according to claim 4, characterized in that, The two pupil dilation regions and the two pupil exit regions are symmetrically arranged on both sides of the pupil entrance region.

6. The AR device according to claim 1, characterized in that, The focal length of the optical engine is greater than 1 mm.

7. An optical waveguide, characterized in that, Applied to the AR device according to claims 1-6, the optical waveguide includes an entrance pupil region, a dilated pupil region, and an exit pupil region, wherein the width of the dilated pupil region increases from the middle of the dilated pupil region to both ends along the length direction of the dilated pupil region.

8. The optical waveguide according to claim 7, characterized in that, The optical waveguide includes two pupil expansion regions and two pupil exit regions, which are symmetrically arranged on both sides of the pupil entrance region.

9. The optical waveguide according to claim 7, characterized in that, The shape of the pupil expansion region is the same as the shape of the propagation region of the image beam within the optical waveguide, and the image beam is a beam emitted by the optomechanical system into the pupil region.

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