Optical waveguide assembly and AR glasses
By setting up stacked waveguide plates with different refractive indexes and specific component structures in the optical waveguide assembly, the problem of ghost image light affecting imaging quality is solved, high-quality imaging and stability are achieved, and production difficulty and cost are reduced.
Patent Information
- Application Number
- CN202510422408.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-03
- Publication Date
- 2025-07-01
AI Technical Summary
In the existing optical waveguide components, some of the coupled light directly enters the coupling area without the turning area, forming a ghost image and affecting the imaging quality.
An optical waveguide assembly is designed. By providing coupling elements and turning elements on the first waveguide plate and coupling elements on the second waveguide plate, the first waveguide plate and the second waveguide plate with different refractive indices are laminated to make light fully reflected and transmitted in the first waveguide plate, and completely reflected and transmitted between the two, to prevent light from entering the second waveguide plate and prevent ghost images from being formed.
Effectively avoid the generation of ghost light, improve the imaging quality of optical waveguide components, and improve the intensity and stability of components by using silicon carbide and glass plates, reduce production costs and chromatic aberrations, and enhance imaging uniformity.
Smart Images
Figure CN120233484A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of optical elements, and more particularly to an optical waveguide assembly and an AR glasses. Background Art
[0002] Augmented Reality (AR) is a technology that enhances a user's perception of the real world by providing information from a computer system, superimposing virtual objects, scenes, or system prompt information generated by the computer onto the real scene, thereby achieving the enhancement of reality. AR glasses based on optical waveguides are the current mainstream solution. The optical waveguide structure is small, light in weight, and powerful in optical functions, and is the core device for realizing lightweight AR glasses.
[0003] Among them, the two-dimensional optical waveguide exit pupil can be expanded in two directions, and better imaging effects can be achieved with a more compact volume. However, in a two-dimensional waveguide, some of the coupled-in light may enter the output region without passing through the light turning part, and this part of the light will form ghost images, thereby affecting the imaging quality of the optical waveguide. Summary of the Invention
[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, the present invention provides an optical waveguide assembly, which can prevent the coupled-in light from directly hitting the output region without passing through the turning region, thereby avoiding the formation of ghost images and improving the imaging quality of the optical waveguide assembly.
[0005] The present invention also provides an AR glasses with the above optical waveguide assembly.
[0006] According to the optical waveguide assembly of the first aspect of the present invention, the optical waveguide assembly includes:
[0007] An optical engine for emitting light;
[0008] A first waveguide plate provided with a coupling element and a turning element thereon, and the refractive index of the first waveguide plate is n1;
[0009] A second waveguide plate stacked with the first waveguide plate, and the second waveguide plate is provided with an output element, and the refractive index of the second waveguide plate is n2;
[0010] The light emitted by the optical engine enters the first waveguide plate through the coupling element, and is totally reflected and transmitted in the first waveguide plate towards the turning element. The turning element expands the light in the first direction to form expanded light, and shoots the expanded light towards the second waveguide plate, so that the expanded light is totally reflected and transmitted between the first waveguide plate and the second waveguide plate. After being totally reflected and transmitted by the first waveguide plate and the second waveguide plate, the expanded light shoots towards the coupling-out element. The coupling-out element expands the expanded light in the second direction and couples out the expanded light to form an image. Wherein, there is an included angle between the first direction and the second direction, and n1>n2.
[0011] In some embodiments, the refractive index n1 of the first waveguide plate and the refractive index n2 of the second waveguide plate satisfy:
[0012] 2*arcsin[sin(1 / 2*F) / n1]<90°-arcsin(n2 / n1);
[0013] 2*arcsin[sin(1 / 2*F) / n1]<arcsin(n2 / n1)-arcsin(1 / n1);
[0014] 2*arcsin[sin(1 / 2*F) / n2]<90°-arcsin(1 / n2);
[0015] Wherein, F is the diagonal field of view angle of the optical waveguide assembly.
[0016] In some alternative embodiments, the first waveguide plate is a silicon carbide plate and the second waveguide plate is a glass plate.
[0017] In some alternative embodiments, the coupling element and the turning element are gratings, and the coupling-out element is an array beam splitter.
[0018] In some alternative embodiments, the coupling element is a reflective grating. The first waveguide plate includes opposite first and second surfaces. The reflective grating is disposed on the first surface, the second waveguide plate is disposed on the second surface, and the optical engine is disposed on the side of the second waveguide plate away from the first waveguide plate.
[0019] In some alternative embodiments, the array beam splitter includes a plurality of beam splitters, and along the direction of light propagation, the reflectivity of the plurality of beam splitters gradually increases.
[0020] In some embodiments, the first waveguide plate and the second waveguide plate are formed into one body by a bonding process.
[0021] In some embodiments, an antireflection film is disposed between the first waveguide plate and the second waveguide plate.
[0022] In some embodiments, a semitransparent and semireflective film is disposed between the first waveguide plate and the second waveguide plate.
[0023] According to the optical waveguide component of the present invention, by disposing the coupling-in element and the turning element on the first waveguide plate, disposing the coupling-out element on the second waveguide plate, laminating the first waveguide plate and the second waveguide plate, and making the refractive index n1 of the first waveguide plate greater than the refractive index n2 of the second waveguide plate, it is possible to make the light rays coupled into the first waveguide plate through the coupling-in element totally reflect and transmit only in the first waveguide plate. After the light rays are expanded by the turning element, the expanded light rays can totally reflect and transmit between the first waveguide plate and the second waveguide plate. Thus, it is ensured that the coupled-in light rays do not enter the second waveguide plate and are not coupled out through the coupling-out element before being expanded by the turning element, thereby avoiding the generation of ghost light rays and improving the imaging quality of the optical waveguide component.
[0024] The AR glasses according to the second aspect of the present invention include the optical waveguide component according to the first aspect of the present invention.
[0025] According to the AR glasses of the present invention, by providing the optical waveguide component of the first aspect described above, the overall performance of the AR glasses is improved.
[0026] The additional aspects and advantages of the present invention will be partly given in the following description, partly will become obvious from the following description, or be understood through the practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 is a schematic diagram of a two-dimensional optical waveguide in the prior art;
[0028] Figure 2 is a three-dimensional schematic diagram of an optical waveguide component according to an embodiment of the present invention;
[0029] Figure 3 is a side view of an optical waveguide component according to an embodiment of the present invention;
[0030] Figure 4 is a side view of an optical waveguide component according to another embodiment of the present invention;
[0031] Figure 5 is a side view of an optical waveguide component according to still another embodiment of the present invention;
[0032] Figure 6 is a side view of an optical waveguide component according to yet another embodiment of the present invention;
[0033] Figure 7It is a side view of an optical waveguide component according to another embodiment of the present invention.
[0034] Reference numerals:
[0035] 100: Optical waveguide component; 10: Optical engine; 20: First waveguide plate; 21: Coupling-in element; 22: Turning element; 30: Second waveguide plate; 31: Coupling-out element; 311: Beam splitter; 40: Anti-reflection film; 50: Semi-transparent and semi-reflective film; 60: Adjusting plate. Detailed implementation manners
[0036] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.
[0037] The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present invention. In addition, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between various embodiments and / or settings discussed. In addition, the present invention provides examples of various specific processes and materials, but those of ordinary skill in the art can realize the applicability of other processes and / or the use of other materials.
[0038] Reference is made below to Figures 2 - 7 Describe an optical waveguide component 100 according to an embodiment of the present invention. The optical waveguide component 100 includes an optical engine 10, a first waveguide plate 20, and a second waveguide plate 30. Among them, the optical engine 10 is used to emit light, and the optical engine 10 can be one of a DLP optical engine, a MicroLED optical engine, and an LCOS optical engine.
[0039] As Figures 2 - 3 shown, a coupling-in element 21 and a turning element 22 are provided on the first waveguide plate 20, and the refractive index of the first waveguide plate 20 is n1;
[0040] The second waveguide plate 30 is stacked with the first waveguide plate 20. A coupling-out element 31 is provided on the second waveguide plate 30, and the refractive index of the second waveguide plate 30 is n2;
[0041] Please continue to refer to Figures 2 - 3 , it should be noted that the first waveguide plate 20 and the second waveguide plate 30 being stacked means that the first waveguide plate 20 and the second waveguide plate 30 are stacked and there is no air gap between the first waveguide plate 20 and the second waveguide plate 30.
[0042] Please continue to refer to Figures 2 - 3 , further, the light emitted by the optical engine 10 enters the first waveguide plate 20 through the coupling element 21 and is totally reflected and transmitted in the first waveguide plate 20 towards the turning element 22. The turning element 22 expands the light in the first direction (such as Figure 2 the X direction shown) to form expanded light, and shoots the expanded light towards the second waveguide plate 30, so that the expanded light is totally reflected and transmitted between the first waveguide plate 20 and the second waveguide plate 30. After the expanded light is totally reflected and transmitted by the first waveguide plate 20 and the second waveguide plate 30, it shoots towards the coupling-out element 31. The coupling-out element 31 expands the expanded light in the second direction (such as Figure 2 the Y direction shown) and couples out the expanded light to form an image. Among them, the first direction and the second direction have an included angle, and n1>n2.
[0043] Please continue to refer to Figures 2 - 3 , it can be understood that after the light emitted by the optical engine 10 passes through the coupling element 21, the coupling element 21 couples the light into the first waveguide plate 20 and totally reflects and transmits it in the first waveguide plate 20. Since the first waveguide plate 20 and the second waveguide plate 30 are stacked, the total reflection angle of the light totally reflected in the first waveguide plate 20 needs to satisfy: n2 / n1 < sinA < 1, where A is the total reflection angle of the light coupled into the first waveguide plate 20 by the coupling element 21 and totally reflected in the first waveguide plate 20. At this time, the light is only totally reflected and transmitted in the first waveguide plate 20.
[0044] Further, when the light totally reflected and transmitted in the first waveguide plate 20 reaches the turning element 22, the turning element 22 expands the light in the first direction to form expanded light and shoots the expanded light towards the second waveguide plate 30. It should be noted that when the expanded light shoots from the first waveguide plate 20 towards the second waveguide plate 30, to avoid the total reflection phenomenon at the interface between the first waveguide plate 20 and the second waveguide plate 30, the incident angle of the expanded light when shooting from the first waveguide plate 20 towards the second waveguide plate 30 needs to satisfy: 1 / n1 < sinB < n2 / n1, where B is the incident angle of the expanded light when shooting from the first waveguide plate 20 towards the second waveguide plate 30. At this time, when the expanded light shoots from the first waveguide plate 20 towards the second waveguide plate 30, the light will not undergo total reflection at the interface between the first waveguide plate 20 and the second waveguide plate 30, and when the light shoots from the second waveguide plate 30 towards the first waveguide plate 20 again, the expanded light will undergo total reflection at the interface between the first waveguide plate 20 and the air and shoot towards the second waveguide plate 30 again.
[0045] Further, when the expanding light enters the second waveguide plate 30 and is incident on the surface of the second waveguide plate 30, since the expanding light needs to undergo total internal reflection between the first waveguide plate 20 and the second waveguide plate 30, the exit angle of the expanding light incident on the surface of the second waveguide plate 30 needs to satisfy: 1 / n2 < sinC < 1, where C is the exit angle of the expanding light from the first waveguide plate 20 to the second waveguide plate 30, that is, the incident angle of the expanding light on the second waveguide plate 30. And, according to the law of refraction, n1sinB = n2sinC.
[0046] At this time, when the expanding light is incident on the interface between the second waveguide plate 30 and air, the expanding light satisfies the total internal reflection condition, undergoes total internal reflection at the interface between the second waveguide plate 30 and air, and is incident on the first waveguide plate 20. And, after refraction at the interface between the second waveguide plate 30 and the first waveguide plate 20, it is incident on the interface between the first waveguide plate 20 and air, and undergoes total internal reflection again at the interface between the first waveguide plate 20 and air and then is incident on the second waveguide plate 30, thereby realizing the total internal reflection transmission of the expanding light between the first waveguide plate 20 and the second waveguide plate 30.
[0047] Among them, the included angle between the first direction and the second direction can be 90°, of course, the embodiments of the present invention do not limit this, and the included angle between the first direction and the second direction can also be 30°, 45°, 60°, 75°, etc.
[0048] The inventors found in actual research that for conventional two-dimensional optical waveguides, such as Figure 1 As shown, since the light rays entering the optical waveguide through the coupling-in region have a certain divergence angle, it is possible that some of the coupled-in light rays enter the coupling-out region without passing through the light ray turning portion, and these light rays will form ghost images in the optical waveguide, ultimately affecting the imaging quality of the optical waveguide.
[0049] In view of this, for the optical waveguide assembly 100 according to the embodiments of the present invention, by disposing the coupling-in element 21 and the turning element 22 on the first waveguide plate 20, disposing the coupling-out element 31 on the second waveguide plate 30, laminating the first waveguide plate 20 and the second waveguide plate 30, and making the refractive index n1 of the first waveguide plate 20 greater than the refractive index n2 of the second waveguide plate 30, it is possible to make the light rays coupled into the first waveguide plate 20 through the coupling-in element 21 only undergo total internal reflection transmission in the first waveguide plate 20, and after the light rays are expanded by the turning element 22, the expanding light rays can undergo total internal reflection transmission between the first waveguide plate 20 and the second waveguide plate 30. Thus, it is ensured that the coupled-in light rays do not enter the second waveguide plate 30 and are not coupled out through the coupling-out element 31 before being expanded by the turning element 22, thereby avoiding the generation of ghost image light rays and improving the imaging quality of the optical waveguide assembly 100.
[0050] Please continue to refer toFigures 2 - 3 , in some embodiments, the refractive index n1 of the first waveguide plate 20 and the refractive index n2 of the second waveguide plate 30 satisfy:
[0051] 2*arcsin[sin(1 / 2*F) / n1]<90°-arcsin(n2 / n1);
[0052] 2*arcsin[sin(1 / 2*F) / n1]<arcsin(n2 / n1)-arcsin(1 / n1);
[0053] 2*arcsin[sin(1 / 2*F) / n2]<90°-arcsin(1 / n2);
[0054] where F is the diagonal field of view angle of the optical waveguide assembly 100.
[0055] It should be noted that by combining the inequalities corresponding to sinA and sinB above, we can obtain 1 / n1 < sinB < n2 / n1 < sinA < 1. Further, we can get arcsin(1 / n1) < B < arcsin(n2 / n1) < A < 90°. From the inequalities related to sinC, we can get arcsin(1 / n2) < C < 90°. Among them, the above angles A and B are the incident angles of total internal reflection transmission in the case where the light rays emitted from the optical machine 10 are perpendicularly incident on the first waveguide plate 20, and the angle C is the total internal reflection incident angle in the second waveguide plate 30. In practical applications, the image light rays projected by the optical machine 10 usually take the light rays of the central pixel point of the picture perpendicular to the waveguide sheet as the center, and at the same time have a certain angular spread, that is, the coupled-in light ray angle is a range of 0° ± 1 / 2*F, where the angle F is the diagonal field of view angle of the optical waveguide assembly 100. According to the law of refraction, the light ray angle ranges in the two refractive index materials of the first waveguide plate 20 and the second waveguide plate 30 can be calculated as 0° ± arcsin[sin(1 / 2*F) / n1] and 0° ± arcsin[sin(1 / 2*F) / n2] respectively. In order to ensure that the optical waveguide assembly 100 can carry such a field of view angle, the value ranges of angles A and B must be able to accommodate the above light ray ranges. Therefore, the refractive index n1 of the first waveguide plate 20 and the refractive index n2 of the second waveguide plate 30 satisfy:
[0056] 2*arcsin[sin(1 / 2*F) / n1]<90°-arcsin(n2 / n1);
[0057] 2*arcsin[sin(1 / 2*F) / n1]<arcsin(n2 / n1)-arcsin(1 / n1);
[0058] 2 * arcsin[sin(1 / 2 * F) / n2] < 90° - arcsin(1 / n2);
[0059] Thus, by setting the first waveguide plate 20 and the second waveguide plate 30 within the above refractive index range, on the one hand, the generation of ghost image light can be avoided. Moreover, by controlling the refractive indices of the first waveguide plate 20 and the second waveguide plate 30 within the above range, the field of view angle of the image can be ensured, improving the imaging quality of the optical waveguide assembly 100; on the other hand, the strength of the optical waveguide assembly 100 can be enhanced, avoiding the breakage of the optical waveguide assembly 100 caused by impacts or drops, etc., and further enhancing the stability of the optical waveguide assembly 100.
[0060] Please continue to refer to Figures 2 - 3 , in some alternative embodiments, the first waveguide plate 20 is a silicon carbide plate and the second waveguide plate 30 is a glass plate. It should be noted that the refractive index of silicon carbide is approximately around 2.6, and the refractive index of ordinary glass is approximately around 1.62. At this time, the optical waveguide assembly 100 has a relatively large field of view angle; and silicon carbide has stable chemical properties, a high thermal conductivity coefficient, a small thermal expansion coefficient, good wear resistance, and high hardness, thereby further enhancing the strength of the optical waveguide assembly 100 and avoiding the breakage of the optical waveguide assembly 100 caused by impacts or drops, etc., and further enhancing the stability of the optical waveguide assembly 100.
[0061] It should be noted that when the refractive index n1 of the first waveguide plate 20 is 2.6, the first waveguide plate 20 can be made of silicon carbide material at this time. And when the refractive index n2 of the second waveguide plate 30 is 1.62, the second waveguide plate 30 can be made of conventional optical glass at this time. At this time, the diagonal field of view angle F of the optical waveguide assembly can reach 40°.
[0062] Please continue to refer to Figures 2 - 3 , in some alternative embodiments, the coupling element 21 and the turning element 22 are gratings, and the coupling-out element 31 is an array beam splitter.
[0063] It should be noted that in a conventional two-dimensional array optical waveguide, its turning structure and coupling-out structure are both array beam splitters. And in the cold processing technology for manufacturing the array optical waveguide, there are many processes of cutting the waveguide plate. Since silicon carbide has a relatively high strength, second only to diamond, the cutting difficulty of the first waveguide plate 20 formed by the silicon carbide plate is relatively large; at the same time, even when using optical glass with conventional strength to manufacture a two-dimensional array optical waveguide, when the first waveguide plate 20 is relatively thin, the spacing between the film layers of the array beam splitter forming the turning structure of the two-dimensional array optical waveguide will be very small. When the thickness of the glass substrate is very low, it is very difficult to ensure the planar surface shape, and at the same time, the number of film layers will increase sharply, and it is very difficult to ensure the parallelism between all the planes where the film layers are located at the same time. All these will greatly increase the difficulty of the cold processing technology for the two-dimensional array optical waveguide.
[0064] Thus, for the optical waveguide assembly 100 according to the embodiments of the present invention, by providing the coupling element 21 and the turning element 22 on the first waveguide plate 20 and setting the coupling element 21 and the turning element 22 as gratings, the process difficulty of manufacturing the optical waveguide assembly 100 can be reduced, and the production cost of the optical waveguide assembly 100 can be lowered.
[0065] It can be understood that the coupling element 21 and the turning element 22 can be formed on the first waveguide plate 20 by means of grating etching on the surface of the first waveguide plate 20. Alternatively, the coupling element 21 and the turning element 22 can also be formed on the surface of the first waveguide plate 20 by means of nanoimprinting. The embodiments of the present invention do not limit this.
[0066] Moreover, since gratings deflect light of different wavelengths to different extents, in a conventional two-dimensional diffractive optical waveguide, since the coupling element 21, the turning element 22, and the coupling-out element 31 are all gratings, the light coupled out in the two-dimensional diffractive optical waveguide has a large chromatic dispersion, resulting in color aberration in the image and reducing the imaging quality.
[0067] Thus, for the optical waveguide assembly 100 according to the embodiments of the present invention, by setting the coupling element 21 and the turning element 22 as gratings and setting the coupling-out element 31 as an array beam splitter, when the expanded light is totally reflected and transmitted between the first waveguide plate 20 and the second waveguide plate 30 to the coupling-out element 31, the array beam splitter expands the expanded light in the second direction and couples it out of the optical waveguide assembly 100 to be projected onto the human eye. Since the array beam splitter only acts on the expanded light through reflection, transmission, etc., chromatic dispersion will not occur, thereby reducing the color aberration of the image output from the optical waveguide assembly 100 and further improving the imaging quality of the optical waveguide assembly 100.
[0068] Of course, in other embodiments of the present invention, the coupling element 21 can also be a prism or a mirror, the turning element 22 can also be an array beam splitter, and the coupling-out element 31 can also be a grating, etc. The embodiments of the present invention do not limit this.
[0069] Please refer to Figure 4 , in some alternative embodiments, the coupling element 21 is a reflective grating. The first waveguide plate 20 includes opposite first and second surfaces. The reflective grating is disposed on the first surface, the second waveguide plate 30 is disposed on the second surface, and the optical engine 10 is disposed on the side of the second waveguide plate 30 away from the first waveguide plate 20.
[0070] Thus, the reflective grating has a high diffraction efficiency, can improve the light utilization rate, and thus further improve the imaging quality of the optical waveguide assembly 100.
[0071] In some alternative embodiments, the array beam splitter includes a plurality of beam splitters 311, and the reflectivity of the plurality of beam splitters 311 gradually increases in the direction of light propagation.
[0072] It should be noted that the plurality of beam splitters 311 are arranged in an array in the direction of light propagation to form an array beam splitter. And in the direction of light propagation, the reflectivity of the plurality of beam splitters 311 gradually increases. That is to say, as the extended light undergoes total internal reflection transmission in the first waveguide plate 20 and the second waveguide plate 30, the proportion of the light reflected by the beam splitter 311 becomes higher and higher. That is, when the extended light is transmitted to the first beam splitter 311, the proportion of the reflected extended light is the lowest, and the proportion of the extended light reflected by the beam splitter 311 further back in the direction of light propagation is higher. Thus, the uniformity of the output image can be improved, and further the imaging quality of the optical waveguide assembly 100 can be enhanced.
[0073] In some embodiments, the first waveguide plate 20 and the second waveguide plate 30 are formed into one body by a bonding process. It can be understood that the bonding process refers to a method of connecting two or more materials together through chemical and / or physical actions, etc. In the manufacturing of optical waveguides, bonding is an important process step. Through the bonding process, waveguide plates of two or more different material layers can be combined together to form a complete optical waveguide device.
[0074] Therefore, for the optical waveguide assembly 100 of the embodiments of the present invention, by using the bonding process to form the first waveguide plate 20 and the second waveguide plate 30 into one body, light loss can be reduced, and the first waveguide plate 20 and the second waveguide plate 30 after bonding maintain high transparency, thereby further improving the imaging quality of the optical waveguide assembly 100; at the same time, since there is no need to provide an adhesive layer between the first waveguide plate 20 and the second waveguide plate 30, the thickness and weight of the optical waveguide assembly 100 can be reduced, enhancing the user experience.
[0075] Specifically, the first waveguide plate 20 and the second waveguide plate 30 can be formed into one body by direct bonding or plasma-activated bonding, etc. Among them, direct bonding refers to a bonding process in which the atoms on the material surface are directly combined under high temperature and high pressure, and plasma-activated bonding refers to a process in which the material surface is treated by plasma to enhance the bonding activity and then bonding is carried out. Of course, the embodiments of the present invention are not limited to the above two bonding methods, as long as the first waveguide plate 20 and the second waveguide plate 30 can be bonded into one body.
[0076] In some other embodiments of the present invention, the first waveguide plate 20 and the second waveguide plate 30 can also be bonded by an optical glue, and the embodiments of the present invention do not limit this.
[0077] Please refer to Figure 5, in some embodiments, an anti-reflection film 40 is disposed between the first waveguide plate 20 and the second waveguide plate 30.
[0078] It should be noted that, due to the different refractive indices of the first waveguide plate 20 and the second waveguide plate 30, when the expanded light is incident from the first waveguide plate 20 to the second waveguide plate 30, or when the expanded light is incident from the second waveguide plate 30 to the first waveguide plate 20, the reflectivity of the light at the interface between the first waveguide plate 20 and the second waveguide plate 30 is relatively high, which may cause partial light loss.
[0079] Therefore, by disposing the anti-reflection film 40 between the first waveguide plate 20 and the second waveguide plate 30, the reflection at the interface between the first waveguide plate 20 and the second waveguide plate 30 can be reduced, so that more expanded light is transmitted from the first waveguide plate 20 into the second waveguide plate 30, or more expanded light is transmitted from the second waveguide plate 30 into the first waveguide plate 20. Thus, more expanded light can be totally reflected and transmitted between the first waveguide plate 20 and the second waveguide plate 30, further improving the imaging quality of the optical waveguide assembly 100.
[0080] In some other embodiments, the anti-reflection film 40 may be disposed only between the first waveguide plate 20 and the second waveguide plate 30 after the turning element 22, that is, the anti-reflection film 40 is disposed only on the path where the expanded light is totally reflected and transmitted between the first waveguide plate 20 and the second waveguide plate 30 after the light is expanded along the first direction by the turning element 22.
[0081] Please refer to Figure 6 , in some embodiments, a semi-transmissive semi-reflective film 50 is disposed between the first waveguide plate 20 and the second waveguide plate 30.
[0082] It should be noted that the light is totally reflected and transmitted only in the first waveguide plate 20 before being transmitted to the turning element 22. After being expanded by the turning element 22, the expanded light is transmitted in the first waveguide plate 20 and the second waveguide plate 30, which may cause the expanded light not to fill the entire first waveguide plate 20 and / or the second waveguide plate 30. That is, there will be a part of the position with light and a part of the position without light at the position of the light coupling element 31 of the second waveguide plate 30, thus having a certain impact on the display effect of the optical waveguide assembly 100.
[0083] Thus, for the optical waveguide assembly 100 according to the embodiments of the present invention, by disposing a semi-reflective and semi-transmissive film 50 between the first waveguide plate 20 and the second waveguide plate 30, when the expanded light rays are incident from the first waveguide plate 20 to the second waveguide plate 30, or from the second waveguide plate 30 to the first waveguide plate 20, the semi-reflective and semi-transmissive film 50 can reflect a part of the expanded light rays and transmit the other part of the expanded light rays. Since the transmission paths of the expanded light rays reflected by the semi-reflective and semi-transmissive film 50 are different from those of the expanded light rays transmitted by the semi-reflective and semi-transmissive film 50, the expanded light rays can fill the entire first waveguide plate 20 and the second waveguide plate 30 as much as possible, further improving the display uniformity of the optical waveguide assembly 100 and enhancing the imaging quality of the optical waveguide assembly 100.
[0084] Please refer to Figure 7 , in some other embodiments, the optical waveguide assembly 100 may further include an adjustment plate 60. The adjustment plate 60 is disposed on a side of the first waveguide plate 20 away from the second waveguide plate 30, and the adjustment plate 60 is disposed after the turning element 22. A semi-reflective and semi-transmissive film 50 is disposed between the first waveguide plate 20 and the adjustment plate 60. When the expanded light rays that are totally reflected between the first waveguide plate 20 and the second waveguide plate 30 are transmitted to the adjustment plate 60, since the semi-reflective and semi-transmissive film 50 is disposed between the first waveguide plate 20 and the adjustment plate 60, therefore, a part of the expanded light rays are reflected by the semi-reflective and semi-transmissive film 50 and continue to be totally reflected and transmitted between the first waveguide plate 20 and the second waveguide plate 30, and the other part of the expanded light rays are transmitted by the semi-reflective and semi-transmissive film 50 and enter the adjustment plate 60, and after being totally reflected by the adjustment plate 60, they enter the first waveguide plate 20 and the second waveguide plate 30 again, so that the expanded light rays can fill the entire first waveguide plate 20 and the second waveguide plate 30 as much as possible, further improving the display uniformity of the optical waveguide assembly 100 and enhancing the imaging quality of the optical waveguide assembly 100.
[0085] Of course, the adjustment plate 60 may also be disposed on a side of the second waveguide plate 30 away from the first waveguide plate 20, and a semi-reflective and semi-transmissive film 50 is disposed between the adjustment plate 60 and the second waveguide plate 30. The implementation principle is similar to that when the adjustment plate 60 is disposed on a side of the first waveguide plate 20 away from the second waveguide plate 30, and will not be described in detail here. The adjustment plate may be a glass plate or the like.
[0086] It should be noted that the above-mentioned beam splitter 311, semi-reflective and semi-transmissive film 50, etc. do not mean that the reflectivity or transmittance of the beam splitter 311 or the semi-reflective and semi-transmissive film 50 to light is 50%. In the embodiments of the present invention, the ratio of the reflectivity and transmittance of the beam splitter 311, semi-reflective and semi-transmissive film 50, etc. to light can be adjusted as needed, and the embodiments of the present invention do not limit this.
[0087] The AR glasses according to the second aspect of the present invention include the optical waveguide component 100 according to the first aspect of the present invention. Specifically, the AR glasses may further include a frame and temple arms. Among them, the first waveguide plate 20 and the second waveguide plate 30 in the optical waveguide component 100 may be disposed in the frame, and the light engine 10 may be disposed on the temple arms, so that the weight distribution of the AR glasses is more uniform, improving the user experience. And when the AR glasses are binocular glasses, the AR glasses may be provided with two frames. It can be understood that the light engine 10 can emit light rays of a virtual image, and through the transmission of the first waveguide plate 20 and the second waveguide plate 30, the light rays of the virtual image are transmitted to the human eye. At the same time, the first waveguide plate 20 and the second waveguide plate 30 are transparent plates, and the human eye can directly view the real-world picture through the first waveguide plate 20 and the second waveguide plate 30, thus realizing augmented display.
[0088] It can be understood that for the AR glasses according to the embodiments of the present invention, by providing the above-mentioned optical waveguide component 100, it can be ensured that the coupled light rays do not enter the second waveguide plate 30 and are not coupled out from the coupling-out element 31 before being expanded by the turning element 22, thereby avoiding the generation of ghost image light rays, improving the imaging quality of the optical waveguide component 100, and further improving the overall performance of the AR glasses.
[0089] The other configurations and operations of the optical waveguide component 100 and the AR glasses according to the embodiments of the present invention are known to those of ordinary skill in the art and will not be described in detail here.
[0090] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.
[0091] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality" means two or more unless otherwise specifically defined.
[0092] In the present invention, unless otherwise clearly specified or defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication between two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0093] In the present invention, unless otherwise clearly specified or defined, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0094] In the description of this specification, the descriptions with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.
[0095] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the claims and their equivalents.
Claims
1. An optical waveguide component, characterized in that: The optical waveguide assembly comprises: An optical machine, the optical machine is used to emit light; A first waveguide plate, wherein a coupling element and a turning element are arranged on the first waveguide plate, and the refractive index of the first waveguide plate is n1; A second waveguide plate, wherein the second waveguide plate is stacked with the first waveguide plate, a coupling-out element is arranged on the second waveguide plate, and the refractive index of the second waveguide plate is n2; The light emitted by the optical machine enters the first waveguide plate through the coupling-in element, and is transmitted by total reflection in the first waveguide plate toward the turning element, the turning element expands the light in the first direction to form an extended light, and emits the extended light toward the second waveguide plate, so that the extended light is transmitted by total reflection between the first waveguide plate and the second waveguide plate, the extended light is transmitted by total reflection between the first waveguide plate and the second waveguide plate, and is emitted to the coupling-out element, the coupling-out element expands the extended light in the second direction, and couples out the extended light to form an image, wherein the first direction and the second direction have an angle, n1>n2.
2. The optical waveguide assembly according to claim 1, characterized in that The refractive index n1 of the first waveguide plate and the refractive index n2 of the second waveguide plate satisfy: 2*arcsin[sin(1 / 2*F) / n1]<90°-arcsin(n2 / n1); 2*arcsin[sin(1 / 2*F) / n1] <arcsin(n2 / n1)-arcsin(1 / n1); 2*arcsin[sin(1 / 2*F) / n2]<90°-arcsin(1 / n2); Wherein, F is the diagonal viewing angle of the optical waveguide component.
3. The optical waveguide assembly according to claim 2, characterized in that The first waveguide plate is a silicon carbide plate, and the second waveguide plate is a glass plate.
4. The optical waveguide assembly according to claim 3, characterized in that The coupling-in element and the turning element are gratings, and the coupling-out element is an array spectroscope.
5. The optical waveguide assembly according to claim 4, characterized in that The coupling element is a reflective grating, the first waveguide plate includes a first surface and a second surface opposite to each other, the reflective grating is arranged on the first surface, the second waveguide plate is arranged on the second surface, and the optical machine is arranged on a side of the second waveguide plate away from the first waveguide plate.
6. The optical waveguide assembly according to claim 4, characterized in that The array beam splitter includes a plurality of beam splitters, and the reflectivity of the plurality of beam splitters gradually increases along the direction in which the light propagates.
7. The optical waveguide assembly according to any one of claims 1 to 6, characterized in that: The first waveguide plate and the second waveguide plate are formed into one body through a bonding process.
8. The optical waveguide assembly according to claim 1, wherein: An anti-reflection film is arranged between the first waveguide plate and the second waveguide plate.
9. The optical waveguide assembly according to claim 1, wherein: A semi-reflective and semi-transmissive membrane is arranged between the first waveguide plate and the second waveguide plate.
10. An AR glasses, characterized in that: An optical waveguide component comprising any one of claims 1 to 9.