Diffraction optical waveguide for improving light output uniformity and its application

Abstract

The present invention mainly provides a coupling component, a coupling assembly, a diffraction optical waveguide for improving light output uniformity, and a projection method thereof, wherein the diffraction optical waveguide for improving light output uniformity is used to project at least one light ray, and is characterized in that the diffraction optical waveguide for improving light output uniformity includes a coupling assembly and a coupling-out component, wherein the coupling assembly is suitable for diffracting the light ray of different viewing angles to the coupling-out region and uniformly covering the coupling-out component. In the diffraction optical waveguide for improving light output uniformity described in the present invention, the coupling assembly can be used in conjunction with the coupling-out component, so that the light ray of different viewing angles can reach the coupling-out component after being diffracted by the coupling assembly and uniformly cover the coupling-out component, thereby improving the utilization rate of the light ray.

Description

Technical Field

[0001] The present invention belongs to the field of optical elements, and in particular relates to a diffraction light waveguide capable of improving light output uniformity and a projection method thereof. Background Art

[0002] Augmented reality (AR) is a technology that blends the real world with virtual information. AR display systems typically include a micro-projector and an optical display. The optical display projects pixels from the micro-display into the user's eye, while the user simultaneously sees the real world through the optical display. The micro-projector provides virtual content to the device, while the optical display is typically a transparent optical component.

[0003] Optical waveguides are a method for realizing optical display screens. When the refractive index of the transmission medium is greater than that of the surrounding medium and the incident angle in the waveguide is greater than the critical angle for total internal reflection, light can be transmitted within the waveguide without leakage, resulting in total internal reflection. After the light from the projector is coupled into the waveguide, the light continues to propagate the image losslessly within the waveguide until it is coupled out by subsequent structures. Currently, optical waveguides on the market are generally divided into geometric array waveguides and diffraction waveguides. Diffraction waveguides are further divided into volume holographic waveguides and surface relief grating waveguides. In essence, they all couple the incident light into the waveguide for transmission through grating diffraction.

[0004] Regarding the technical parameters and specifications of AR waveguides, these primarily include field of view (FOV), eye relief, and eyebox size. The FOV is typically expressed as a diagonal angle, such as 40°, corresponding to approximately 35° (H) x 20° (V) for a 16:9 aspect ratio. The viewing distance is typically around 20-25mm, which generally meets the wearer requirements of most users, including those wearing glasses. The eyebox size determines the range of free eye movement. A larger size reduces the likelihood of image loss, thus providing greater adaptability. The horizontal size of the eyebox needs to accommodate the range of human exit pupil distances and provide sufficient margin for varying horizontal wear standards. The vertical size of the eyebox needs to adapt to the user's vertical wear standard. A size of 15mm (H) x 10mm (V) is generally considered sufficient for a basic user experience.

[0005] AR waveguides are optimized for high efficiency and good uniformity. High efficiency aims to achieve higher brightness output under the same micro-projection input, so that the image seen by the human eye is bright enough. Uniformity includes FOV uniformity, that is, the full field of view image seen by the human eye has good brightness and color uniformity. It also includes eyebox uniformity, that is, the brightness difference received by the human eye at different positions of the eyebox (or when worn by users with different pupil distances and nose bridge heights) is minimized, and it is expected that different positions have good FOV uniformity.

[0006] More specifically, to ensure wearing comfort, the optical and mechanical position of waveguide glasses usually needs to be kept at a certain distance from the human eye, and to obtain the same size of the orbital range, there are two ways: Method 1 is as follows: Figure 1A 、 1B As shown, it shows the optical paths of (0°, 0°) and (17°, 10°) when the spacing between the coupling-in grating 1 and the coupling-out grating 2 is small. Figure 1C The effective outcoupling component 3 is shown. When the outcoupling grating area 3 is large and the spacing between the incoupling grating 1 and the outcoupling grating 2 is small, this configuration ensures that light from the entire field of view reaches and covers the entire orbital range, achieving good field of view uniformity and orbital uniformity. However, under this architecture, light is diffracted multiple times before it can be deflected into the orbital range. Each time light is diffracted by the two-dimensional grating, a certain degree of energy loss occurs, and part of the light beam reaches an ineffective area that does not contribute to the overall efficiency, resulting in low overall efficiency. Therefore, to improve efficiency, it is usually necessary to design the incoupling grating 1 into a sawtooth grating, a tilted grating, or require additional coating, all of which greatly increase the process difficulty and cost.

[0007] Method 2: Figure 2A 、 2B As shown in FIG, the optical paths when the spacing between the coupling-in grating 1 and the coupling-out grating 2 is large (0°, 0°) and (17°, 10°) are shown. The coupling-out grating area 3 is small and the spacing between the coupling-in grating 1 and the coupling-out grating 2 is large. This setting can reduce efficiency loss, as shown in FIG. Figure 2C As shown in the figure, the entire two-dimensional grating area is the "effective outcoupling component 3", but when the field of view is large, the light cannot cover the entire orbital range, resulting in extremely poor field angle uniformity in certain areas of the orbital range. Figure 3A The following diagram shows the pupil position detection when the distance between the coupling-in grating 1 and the coupling-out grating 2 is large. Figure 3B Shown is the brightness distribution of the full field of view detected in the upper right corner of the orbital range. Summary of the Invention

[0008] An advantage of the present invention is that it provides a coupling component, which is suitable for coupling a light and can diffract the coupled light along multiple desired directions, thereby changing the projection direction of the light.

[0009] Another advantage of the present invention is to provide a coupling component that is suitable for coupling a light ray and can expand the diffraction width of the coupled light ray and diffract it in the same direction, thereby improving the diffraction efficiency and diffraction effect of the light ray.

[0010] Another advantage of the present invention is that it provides a coupling component, which is suitable for use in conjunction with a coupling component so that light with different field angles can reach the coupling component after diffraction by the coupling component and evenly cover the coupling component, thereby improving the utilization rate of the light.

[0011] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity can reduce the energy loss caused by each light beam being diffracted by the two-dimensional grating, thereby preventing part of the light beam from reaching an invalid area that does not contribute to the overall efficiency, thereby improving the overall efficiency of the light.

[0012] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity can improve the diffraction uniformity of light without increasing the process steps or process difficulty, thereby improving the diffraction efficiency of light.

[0013] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity can cover the entire dynamic orbital range as much as possible, thereby improving the uniformity of the field of view angle in all areas of the dynamic orbital range under a large field of view.

[0014] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving the uniformity of light output. The diffraction optical waveguide for improving the uniformity of light output is provided with an independent deflection grating spaced apart from the coupling-in grating and the coupling-out grating between the coupling-in grating and the coupling-out grating, so as to reduce the number of diffractions of light and reduce the loss of light output efficiency, thereby improving the output efficiency of light.

[0015] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity, which enables light of different viewing angles to better cover the effective coupling-out component, thereby improving light output uniformity.

[0016] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving the uniformity of light output. The diffraction optical waveguide for improving the uniformity of light output is configured by setting three one-dimensional gratings with different periodic directions or a two-dimensional grating that is equivalent to a one-dimensional grating in three directions, and two turning gratings to achieve diffraction of incident light at different angles. Light at different angles is diffracted and directed to different areas, so that light at different field angles can better cover the effective coupling-out component.

[0017] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity is applicable to different types of gratings, thereby improving the scope of application and ease of use of the diffraction optical waveguide for improving light output uniformity described in the present invention.

[0018] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving the uniformity of light output. The diffraction optical waveguide for improving the uniformity of light output can achieve a better balance and improvement in the overall uniformity of light output by optimizing the position and area ratio of the coupling grating and the size and shape of the two turning gratings.

[0019] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity can also further improve light utilization efficiency and light output uniformity by optimizing microscopic parameters such as the depth, duty cycle, and tilt angle of each grating.

[0020] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving the uniformity of light output. The diffraction optical waveguide for improving the uniformity of light output can optimize the coupled grating microstructure to concentrate the diffraction efficiency in three different directions, and further optimize the efficiency ratio distributed in the three directions, thereby further improving the balance between the overall uniformity of light output and the light utilization efficiency.

[0021] Another advantage of the present invention is that it provides a diffraction optical waveguide for improving light output uniformity. The diffraction optical waveguide for improving light output uniformity can design the coupling-in grating and the coupling-out grating to have different microstructure parameters according to actual conditions, thereby making the diffraction optical waveguide for improving light output uniformity described in the present invention further meet specific application requirements.

[0022] Another advantage of the present invention is that it provides a method for projecting a diffraction light waveguide for improving light output uniformity, which enables the light projected from the coupling-in component to evenly cover the coupling-out component, thereby improving light output efficiency.

[0023] Another advantage of the present invention is that it provides a method for projecting a diffraction optical waveguide for improving the uniformity of light output. The method for projecting a diffraction optical waveguide for improving the uniformity of light output can adapt to a diffraction optical waveguide structure in which the coupling component is a one-dimensional grating or a two-dimensional grating, thereby improving the scope of application of the method for projecting a diffraction optical waveguide for improving the uniformity of light output.

[0024] In order to achieve at least one of the above-mentioned advantages of the invention, the present invention mainly provides a coupling component for coupling a light ray, wherein the coupling component includes three one-dimensional gratings, and the grating directions of the three one-dimensional gratings are respectively along the first axis direction and at a preset angle with the first axis.

[0025] In some embodiments, the coupling component includes a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are all relief gratings or holographic gratings.

[0026] In some embodiments, the first grating, the second grating, and the third grating respectively include a plurality of protrusions and a plurality of grooves, wherein the protrusions and the grooves are alternately and evenly arranged.

[0027] In some embodiments, the first grating, the second grating and the third grating are formed by holographic exposure to form periodic light and dark stripes in the material.

[0028] In some embodiments, the grating direction of the first grating is along the first axis, the grating direction of the second grating is 60° to the first axis, and the grating direction of the third grating is -60° to the first axis.

[0029] The present invention further provides a coupling-in component, which is configured as a two-dimensional grating.

[0030] In some embodiments, the two-dimensional grating is a second two-dimensional grating, and the second two-dimensional grating can be equivalent to a ninth grating, a tenth grating, and an eleventh grating, wherein the ninth grating is arranged along a grating direction along a second axis, the tenth grating is arranged along a grating direction at 60° to the second axis, and the eleventh grating is arranged along a grating direction at -60° to the second axis.

[0031] The present invention further provides a coupling component for coupling a light ray, wherein the coupling component comprises a coupling part and a turning part, wherein the turning part is arranged in the light emitting area of ​​the coupling part to be suitable for diffracting the light ray emitted from the coupling part.

[0032] In some embodiments, the coupling component includes a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are respectively arranged along a first axis and grating directions at 60° and -60° to the first axis.

[0033] In some embodiments, the turning component includes a fourth grating and a fifth grating, wherein the fourth grating is arranged on the left side of the second grating and the fifth grating is arranged on the right side of the third grating, so that the light diffused from the second grating and the third grating can be deflected by the fourth grating and the fifth grating respectively.

[0034] In some embodiments, the grating direction and period of the fourth grating are the same as those of the third grating, and the grating direction and period of the fifth grating are the same as those of the second grating.

[0035] In some embodiments, the fourth grating and the third grating have the same direction and period, and the fifth grating and the second grating have the same direction and period, so that the direction of the light after passing through the second grating and being deflected by the fourth grating is parallel to the direction of the light after passing through the third grating element and being deflected by the fifth grating, and is also parallel to the light after passing through the first grating.

[0036] In some embodiments, the coupling component is implemented as a two-dimensional grating, and the two-dimensional grating can be equivalent to a ninth grating, a tenth grating, and an eleventh grating, wherein the ninth grating, the tenth grating, and the eleventh grating are respectively one-dimensional gratings, and the grating directions of the ninth grating, the tenth grating, and the eleventh grating are respectively arranged along the second axis and at 60° or -60° to the second axis.

[0037] In some embodiments, periods of the ninth grating, the tenth grating, and the eleventh grating are respectively the same as periods of the fourth grating and the fifth grating.

[0038] In some embodiments, the turning component includes a fourth grating and a fifth grating, wherein the fourth grating and the eleventh grating have the same direction and period, and the fifth grating and the tenth grating have the same direction and period, so that the direction of the light after passing through the tenth grating and being turned by the fourth grating is parallel to the direction of the light after passing through the eleventh grating and being turned by the fifth grating, and is also parallel to the light after passing through the ninth grating.

[0039] The present invention further provides a diffraction light waveguide for improving light output uniformity, which is used to project at least one light ray. The diffraction light waveguide for improving light output uniformity includes a coupling component and a coupling-out component, wherein the coupling-in component is suitable for diffracting the light ray of different field angles to the coupling-out area and uniformly covering the coupling-out component.

[0040] In some embodiments, the coupling component includes at least one coupling component and a turning component. The turning components are arranged on both sides of the coupling component and can further diffract the light diffracted by the coupling component and make the diffracted light reach the outcoupling component.

[0041] In some embodiments, the coupling component includes a first grating, a second grating and a third grating, wherein the first grating, the second grating and the third grating are respectively one-dimensional gratings, and the first grating, the second grating and the third grating are respectively arranged along the first axis and the grating directions at 60° and -60° to the first axis.

[0042] In some embodiments, the turning component includes a fourth grating and a fifth grating, wherein the fourth grating is arranged on the left side of the second grating and the fifth grating is arranged on the right side of the third grating, so that the light diffused from the second grating and the third grating can be deflected by the fourth grating and the fifth grating respectively.

[0043] In some embodiments, the outcoupling component is configured as a plurality of one-dimensional gratings or a first two-dimensional grating.

[0044] In some embodiments, the first two-dimensional grating can be equivalent to a sixth grating, a seventh grating and an eighth grating, wherein the sixth grating, the seventh grating and the eighth grating are all one-dimensional gratings, and the sixth grating is arranged along the grating direction of the second axis, the seventh grating is arranged along the grating direction at 60° to the second axis, and the eighth grating is arranged along the grating direction at -60° to the second axis.

[0045] In some embodiments, the coupling component is configured as a second two-dimensional grating.

[0046] In some embodiments, the second two-dimensional grating can be equivalent to a ninth grating, a tenth grating, and an eleventh grating, wherein the ninth grating is arranged along the second axis, the tenth grating is arranged along a grating direction at 60° to the second axis, and the eleventh grating is arranged along a grating direction at -60° to the second axis.

[0047] In some embodiments, the ninth grating, the tenth grating, the eleventh grating, and the fourth grating, the fifth grating, the sixth grating, the seventh grating, and the eighth grating have the same period.

[0048] In some embodiments, the method further comprises at least one transparent parallel waveguide substrate, and the coupling-in component, the turning component and the coupling-out component are respectively disposed on the waveguide substrate.

[0049] In some embodiments, the waveguide substrate has a front surface and a rear surface, and the coupling-in component, the turning component, and the coupling-out component are respectively disposed on the front surface or the rear surface of the waveguide substrate.

[0050] In some embodiments, the coupling-in component and the coupling-out component are respectively disposed on different surfaces of the waveguide substrate.

[0051] The present invention further provides a diffraction light waveguide projection method for improving light uniformity, which is used to project a light beam. The diffraction light waveguide projection method for improving light uniformity comprises the following steps:

[0052] 1001: Projecting the light onto an incoupling component for diffraction; and

[0053] 1002: The light diffracted by the coupling component can enter a coupling component for coupling out, and the light entering the coupling component can evenly cover the coupling component.

[0054] In some embodiments, step 1001 further includes the steps of:

[0055] 10011: The coupling component includes a coupling component and a turning component, wherein the light is projected onto the coupling component for diffraction, and the diffracted light can be diffracted along the first axis and in directions at 60° and -60° to the first axis respectively; and

[0056] 10012: The light rays in directions of 60° and -60° to the first axis can respectively enter the turning component for further diffraction and then reach the outcoupling component.

[0057] In some embodiments, in step 1001, the coupling component is configured to include a first grating, a second grating, and a third grating, wherein the first grating, the second grating, and the third grating are respectively one-dimensional gratings, and the first grating, the second grating, and the third grating are respectively arranged along the first axis and at grating directions of 60° and -60° to the first axis.

[0058] In some embodiments, in step 1001, the coupling component is configured as a second two-dimensional grating, and the second two-dimensional grating can be equivalent to a ninth grating, a tenth grating, and an eleventh grating, wherein the ninth grating is arranged along the second axis, the tenth grating is arranged along a grating direction at 60° to the second axis, and the eleventh grating is arranged along a grating direction at -60° to the second axis.

[0059] Further objects and advantages of the present invention will be fully apparent from an understanding of the following description and accompanying drawings.

[0060] These and other objects, features and advantages of the present invention will be more fully reflected in the following detailed description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1A and Figure 1B Schematic diagram of the optical path when the coupling-in and coupling-out distances in the existing diffraction optical waveguide are relatively close.

[0062] Figure 1C This is a schematic diagram of an effective outcoupling component in an existing diffraction optical waveguide when the light incoupling and outcoupling distance is relatively short.

[0063] Figure 2A and Figure 2B Schematic diagram of the optical path when the coupling-in and coupling-out distances in the existing diffraction optical waveguide are long.

[0064] Figure 2C This is a schematic diagram of an effective outcoupling component in an existing diffraction optical waveguide when the light incoupling and outcoupling distance is long.

[0065] Figure 3A This is a schematic diagram of pupil position detection when the distance between light coupling-in and light coupling-out in an existing diffraction waveguide is long.

[0066] Figure 3B This is the brightness distribution diagram of the entire field of view when the light coupling-in and coupling-out distance in the existing diffraction waveguide is long.

[0067] Figure 4A This is a schematic structural diagram of a first embodiment of a diffraction light waveguide for improving light output uniformity according to the present invention.

[0068] Figure 4B for Figure 4A Schematic diagram of the enlarged structure of the side view and top view at D of the first embodiment of the diffraction light waveguide for improving light uniformity.

[0069] Figure 4C for Figure 4A Schematic diagram of the enlarged structure of the side view and top view at E of the first embodiment of the diffraction light waveguide for improving the uniformity of light output.

[0070] Figures 5A to 5C for Figure 4A Schematic diagram of the light paths at different angles of the first embodiment of the diffraction waveguide for improving light output uniformity.

[0071] Figures 6A to 6C for Figure 4AThe schematic diagram of the three-dimensional structure of the first embodiment of the diffraction light waveguide for improving the uniformity of light output shows a situation where the coupling component, the turning component and the coupling-out component are respectively arranged on the front and back surfaces of the diffraction substrate.

[0072] 7A to 7D for Figure 4A Schematic diagram of the three-dimensional structure of the light path at different angles of the first embodiment of the diffraction light waveguide for improving light uniformity.

[0073] Figure 8 for Figure 4A K-domain analysis diagram of the first embodiment of the diffraction waveguide for improving light uniformity before reaching the two-dimensional grating.

[0074] Figure 9 for Figure 4A K-domain analysis diagram of the first embodiment of the diffraction waveguide for improving light uniformity after reaching the two-dimensional grating.

[0075] Figure 10 This is a schematic structural diagram of a second embodiment of a diffraction light waveguide for improving light output uniformity according to the present invention.

[0076] Figure 11 Schematic diagram of the steps of the projection method of the diffraction light waveguide for improving light output uniformity according to the present invention. DETAILED DESCRIPTION

[0077] The following description is intended to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are for illustrative purposes only, and those skilled in the art will readily appreciate other obvious variations. The basic principles of the present invention defined in the following description may be applied to other embodiments, variations, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the present invention.

[0078] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0079] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the elements may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0080] The present invention mainly provides a coupling component, a coupling assembly, a diffraction light waveguide for improving the uniformity of light output and a projection method thereof, which are used to couple and project a light 20. Figures 4A to 9 FIG2 shows a schematic structural diagram of the coupling-in component 11, coupling assembly 100, and diffractive optical waveguide 10 for improving light output uniformity according to a first embodiment of the present invention, a partially enlarged stereoscopic schematic diagram, and a K-domain analysis diagram of the light 20 before and after reaching the first two-dimensional grating 130. The diffractive optical waveguide 10 diffuses the light 20 before reaching the effective coupling-out component 13, so that light at different viewing angles can cover the orbital range, achieving good uniformity.

[0081] More specifically, in a first embodiment of the diffractive optical waveguide 10 for improving light output uniformity according to the present invention, the diffractive optical waveguide 10 for improving light output uniformity includes a coupling component 11, a turning component 12, a coupling-out component 13 and a waveguide substrate 15, wherein the coupling component 11, the turning component 12 and the coupling-out component 13 are all arranged on the waveguide substrate 15, wherein the turning component 12 is arranged in the light output region of the coupling component 11 and can diffract the light 20 emitted by the coupling component 11 and enter the coupling-out component 13, and the coupling component 11 and the turning component 12 form a coupling component 100, so that the light 20 reaches the coupling-out component 13 through diffraction by the coupling component 100.

[0082] like Figure 4A As shown, the coupling component 11 includes a first grating 111, a second grating 112 and a third grating 113, wherein the first grating 111, the second grating 112 and the third grating 113 are all one-dimensional gratings, and the grating direction of the first grating 111 is arranged along a first axis, i.e., the y-axis direction in the figure, and the second grating 112 and the third grating 113 are 60° and -60° respectively relative to the y-axis, that is, the first grating 111, the second grating 112 and the third grating 113 are arranged at an angle of 60°.

[0083] The turning component 12 includes a fourth grating 121 and a fifth grating 122, wherein the fourth grating 121 is arranged on the left side of the second grating 112, and the fifth grating 122 is arranged on the right side of the third grating 113, so that the light 20 diffused from the second grating 112 and the third grating 113 are respectively deflected downward to reach the coupling component 13 and uniformly cover the coupling component 13.

[0084] Specifically, in the first embodiment of the present invention, the first grating 111, the second grating 112, and the third grating 113 have different periodic directions. The first grating 111 has a grating direction along the y-axis, the second grating 112 has a grating direction at 60° to the y-axis, and the third grating 113 has a grating direction at -60° to the y-axis. The fourth grating 121 and the fifth grating 122 are also one-dimensional gratings. The fourth grating 121 and the fifth grating 122 have the same direction and period as the third grating 113, and the fifth grating 122 has the same direction and period as the second grating 112. This ensures that the direction of the light 20 after passing through the second grating 112 and being deflected by the fourth grating 121 is parallel to the direction of the light 20 after passing through the third grating 113 and being deflected by the fifth grating 122, and is also parallel to the light 20 after passing through the first grating 111.

[0085] like Figure 4B As shown, the first grating 111, the second grating 112 and the third grating 113 are surface relief gratings, each having at least one protrusion 1111 and one groove 1112, wherein the protrusions 1111 and the grooves 1112 are evenly arranged, and the protrusions 1111 and the grooves 1112 of the first grating 111 are in different directions from the protrusions 1111' and the grooves 1112' of the second grating 112 and the protrusions and grooves of the third grating 113, so that the first grating 111, the second grating 112 and the third grating 113 have different periodic arrangements. The protrusions 1111 and the grooves 1112 in the first grating 111 are evenly arranged along the y-axis direction, the protrusions 1111' and the grooves 1112' in the second grating 112 are evenly arranged along a direction at 60° to the y-axis, and the protrusions and grooves in the third grating 113 are evenly arranged along a direction at -60° to the y-axis, so that the directions of the first grating 111, the second grating 112, and the third grating 113 form an angle of 60° with each other.

[0086] like Figure 4C As shown, in the first embodiment of the present invention, the coupling-out component 13 is configured as at least a first two-dimensional grating 130, and the first two-dimensional grating 130 can be equivalent to a sixth grating 131, a seventh grating 132 and an eighth grating 133 in three directions, wherein the directions of the sixth grating 131, the seventh grating 132 and the eighth grating 133 are staggered and form an angle of 60° with each other, so that the light 20 can be diffracted in the directions corresponding to the sixth grating 131, the seventh grating 132 and the eighth grating 133.

[0087] As shown in the figure, in the first embodiment of the present invention, the first two-dimensional grating 130 is implemented as a surface relief grating, which includes a plurality of cylindrical protrusions 1311, and the cylindrical protrusions 1311 are arranged periodically, so that the light 20 can be diffracted in the directions corresponding to the sixth grating 131, the seventh grating 132 and the eighth grating 133.

[0088] In addition, the directions of the first grating 111, the second grating 112 and the third grating 113 can be set according to actual conditions, and the sixth grating 131, the seventh grating 132 and the eighth grating 133 can also be set in other directions, such as determined according to the directions of the first grating 111, the second grating 112 and the third grating 113.

[0089] Furthermore, those skilled in the art can optimize the positions and area proportions of the first grating 111, the second grating 112, and the third grating 113, as well as the sizes and shapes of the fourth grating 121 and the fifth grating 122, so as to achieve a better balance between the overall uniformity and efficiency of the coupling component 100.

[0090] Furthermore, microscopic parameters such as the depth, duty cycle and / or tilt angle of the first grating 111, the second grating 112, the third grating 113, the fourth grating 121, the fifth grating 122, the sixth grating 131, the seventh grating 132 and / or the eighth grating 133 can also be optimized.

[0091] Furthermore, the types of gratings in the coupling component 11, the transition component 12, and the coupling component 13 can also be adjusted according to specific circumstances. For example, holographic gratings can be used, i.e., the first grating 111, the second grating 112, and the third grating 113 are configured to form periodic light and dark stripes within the material through holographic exposure. In other words, as long as the above-mentioned disclosure of the present invention adopts the same or similar technical solutions as the present invention, solves the same or similar technical problems as the present invention, and achieves the same or similar technical effects as the present invention, they are all within the scope of protection of the present invention, and the specific embodiments of the present invention are not limited thereto.

[0092] like Figures 5A to 7D As shown, in the first embodiment of the present invention, the waveguide substrate 15 is a transparent parallel waveguide with a certain thickness, having a front surface 151 and a rear surface 152, and the coupling component 11, the turning component 12 and the coupling component 13 can be respectively arranged on the front surface 151 and / or the rear surface 152 of the waveguide substrate 15. Figure 6AAs shown, the coupling component 11, the turning component 12 and the coupling component 13 are respectively arranged on the front surface 151 of the waveguide substrate 15. Figure 6B As shown, the coupling component 11 is arranged on the rear surface 152 of the waveguide substrate 15, and the turning component 12 and the coupling component 13 are arranged on the front surface 151 of the waveguide substrate 15. Figure 6C As shown, the outcoupling component 13 is disposed on the rear surface 152 of the waveguide substrate 15 , and the incoupling component 11 and the turning component 12 are respectively disposed on the front surface 151 of the waveguide substrate 15 .

[0093] However, the specific embodiments of the present invention are not limited to these. Those skilled in the art may further adjust the arrangement of the coupling-in component 11, the turning component 12, and the coupling-out component 13 in the diffractive optical waveguide of the present invention according to specific circumstances. As long as, based on the above disclosure, a technical solution identical or similar to that of the present invention is adopted, the technical problem identical or similar to that of the present invention is solved, and the technical effect identical or similar to that of the present invention is achieved, it falls within the scope of protection of the present invention, and the specific embodiments of the present invention are not limited to these.

[0094] In addition, as a variation of the first embodiment of the present invention, the outcoupling component 13 may include two groups of one-dimensional gratings, the two groups of one-dimensional gratings are respectively located on the front surface 151 and the rear surface 152 of the waveguide substrate 15, and the directions of the two groups of one-dimensional gratings are respectively 60° and -60° to the direction of the first grating 111 in the coupling component 11.

[0095] When the light 20 enters the coupling component 11, the light 20 passes through the first grating 111 in the coupling component 11, is diffracted by the first grating 111, reaches the coupling component 13, and is coupled out by the coupling component 13 to reach the orbital range.

[0096] Similarly, the light 20 passing through the second grating 112 in the coupling-in component 11 is diffracted by the second grating 112 and reaches the fourth grating 121 in the deflection component 12. It is deflected by the fourth grating 121 and reaches the decoupling component 13. It is then coupled out by the decoupling component 13 and reaches the orbital region. Unlike the aforementioned case where the light 20 directly reaches the decoupling component 13 after being diffracted by the first grating 111, the light 20 deflected by the second grating 112 and the fourth grating 121 can cover the area to the left of the first two-dimensional grating 130 in the decoupling component 13.

[0097] Similarly, the light 20 passing through the third grating 113 in the coupling-in component 11 is diffracted by the third grating 113 and reaches the fifth grating 122 in the deflection component 12. The light 20 is deflected by the fifth grating 122 and reaches the decoupling component 13. The decoupling component 13 couples the light 20 to the orbital region. Unlike the aforementioned case where the light 20 directly reaches the decoupling component 13 after being diffracted by the first grating 111, the light 20 deflected by the third grating 113 and the fifth grating 122 can cover the area to the right of the first two-dimensional grating 130 in the decoupling component 13.

[0098] Therefore, if Figure 7D As shown, the light 20 passing through the coupling-in component 11 undergoes the combined action of the coupling-in component 11, the turning component 12, and the coupling-out component 13, so that the range of the coupled-out light 20 can reach the desired range of the light 20. Therefore, the diffraction optical waveguide described in the present invention can improve the light output uniformity and light output efficiency, so that the human eye can see the complete field of view in the desired area and the light 20 entering from the coupling-in component 11 can evenly cover the coupling-out component 13.

[0099] like Figure 8 and Figure 9 As shown, there are K-domain analysis diagrams of the light 20 with different field angles before reaching the first two-dimensional grating 130 of the outcoupling component 13 and K-domain analysis diagrams after reaching the first two-dimensional grating 130 of the outcoupling component 13.

[0100] like Figure 8 As shown, in the coupling component 11, after diffraction by the first grating 111, the second grating 112 and the third grating 113, the diffraction order 1 is totally reflected in the waveguide substrate 15, and the corresponding area A in the K domain passes through the grating vector Then it is translated to the area B, area D and area C between the inner and outer circles; then it encounters the fourth grating 121 and the fifth grating 122 in the turning component 12, where it corresponds to the reflection order 0 during total reflection, and the wave vector remains unchanged. At the same time, a part of the light is diffracted by the fourth grating 121 and the fifth grating 122 in the turning component 12, and the diffraction order 1 is deflected in the waveguide substrate 15 and propagates along the y direction, corresponding to the areas D and C in the K domain respectively passing through the grating vector After that, it is translated to area B, and is still between the inner and outer circles, indicating that it is still totally reflected in the waveguide substrate 15; then it encounters the outcoupling grating 130, and the first order of diffraction is coupled out and enters the human eye, corresponding to area B in the K domain through the grating vector or or After that, it is translated back to area A in the inner circle, that is, the light beam returns to the air and propagates in the same direction as the incident light. It should be noted that the necessary condition for the outcoupling direction of the light beam to be the same as the coupling direction is that the grating vector must satisfy the vector sum of the grating vector to be zero, as shown in Vector graphics can eventually close on themselves.

[0101] After the light 20 reaches the first two-dimensional grating 130 of the outcoupling component 13, Figure 9 As shown, the light 20 is diffracted by the coupling component 11 and the turning component 12 and then totally reflected in the waveguide and propagates in the +y direction, corresponding to the region A in the K domain through the grating vector Then it is translated to the area B between the inner and outer circles until it encounters the first two-dimensional grating 130. The light beam is divided into four parts: one part is directly coupled out by the diffraction of the sixth grating 131, and the corresponding area B in the K domain is directly coupled out by the grating vector After that, it is translated back to area A in the inner circle, that is, the light beam returns to the air and propagates; a part of it is diffracted and transmitted toward the lower left and lower right sides respectively by the seventh grating 132 and the eighth grating 133, and when it encounters the first two-dimensional grating 130 again, part of it continues to be totally reflected along the original direction, and the wave vector remains unchanged; part of it is diffracted by the eighth grating 133 and the seventh grating 132 and then coupled out, and part of it is diffracted by the eighth grating 133 and the seventh grating 132 in the corresponding K domain. Then it is translated to the area C and D between the inner and outer circles, and then it is raster vector The light beam is translated to area A in the inner circle and propagates back into the air; another part continues to be totally reflected in the +y direction, and the wave vector in the K domain remains unchanged. When it encounters the first two-dimensional grating 130 again, it is divided into four parts again.

[0102] like Figure 10 As shown in FIG. 1 , a second preferred embodiment of the diffraction waveguide 10 ′ for improving light output uniformity according to the present invention is shown. Different from the first embodiment, in the second embodiment, the coupling component 14 is implemented as a second two-dimensional grating 140. The second two-dimensional grating 140 can be equivalent to one-dimensional gratings in three directions, that is, the coupling component 14 can be equivalent to a ninth grating 141, a tenth grating 142, and an eleventh grating 143. The ninth grating 141, the tenth grating 142, and the eleventh grating 143 are one-dimensional gratings, and the grating directions of the ninth grating 141, the tenth grating 142, and the eleventh grating 143 form an angle of 60° with each other.

[0103] In addition, in the second embodiment of the diffraction waveguide 10' for improving light output uniformity according to the present invention, the periods of the ninth grating 141, the tenth grating 142, and the eleventh grating 143 in the coupling-in component 14 are the same as the periods of the fourth grating 121', the fifth grating 122' in the turning component 12', and the sixth grating 131', the seventh grating 132', and the eighth grating 133' in the coupling-out component 13'. By optimizing the microstructures of the ninth grating 141, the tenth grating 142, and the eleventh grating 143 in the coupling-in component 14, the diffraction efficiency is concentrated in three directions along the y-axis and at angles of 60° and -60° to a second axis, i.e., the y-axis in the figure, respectively.

[0104] In addition, those skilled in the art can further optimize and distribute the efficiency ratios in the above three directions, so as to achieve a certain balanced output in terms of the overall uniformity and efficiency of the light output of the outcoupling component 13 ′.

[0105] It should be emphasized that in the second embodiment of the diffractive optical waveguide 10' for improving light output uniformity according to the present invention, although both the coupling-in component 14 and the coupling-out component 13' are implemented as two-dimensional gratings, the grating structure parameters of the second two-dimensional grating 140 of the coupling-in component 14 and the first two-dimensional grating 130 of the coupling-out component 13' are independent. In other words, the grating microstructure of the second two-dimensional grating 140 of the coupling-in component 14 and the grating microstructure of the first two-dimensional grating 130 of the coupling-out component 13' are not necessarily the same, and those skilled in the art may design them according to actual circumstances.

[0106] In addition, those skilled in the art can also determine the microstructure shape of the coupling component 14 and the position, size and shape of the two turning gratings according to actual conditions, so as to achieve a better balance between the overall uniformity and efficiency of the coupling component 100'.

[0107] Furthermore, the present invention provides a method for projecting a diffraction light guide 10 for improving light uniformity, which is used to project a light 20, such as Figure 11 FIG. 1 is a schematic diagram of the steps of a first embodiment of a method for projecting a diffractive light guide 10 for improving light uniformity according to the present invention. The method for projecting a diffractive light guide 10 for improving light uniformity includes the following steps:

[0108] 1001: Projecting the light 20 onto a coupling element 100 for diffraction; and

[0109] 1002 : The light 20 diffracted by the coupling component 100 can enter a coupling component 13 for coupling out, wherein the light 20 entering the coupling component 11 can evenly cover the coupling component 13 .

[0110] Furthermore, in the step 1001, the following steps are further included:

[0111] 10011: The coupling component 100 includes at least one coupling component 11 and a deflection component 12, wherein the light 20 is projected onto the coupling component 11 for diffraction, and the diffracted light 20 is irradiated along the y-axis and at directions of 60° and -60° to the y-axis respectively; and

[0112] 10012: The light 20 with an angle of 60° and −60° to the y-axis respectively can enter the turning component 12 and then be further diffracted before reaching the coupling-out component 13.

[0113] Preferably, in the first embodiment of the projection method of the diffraction optical waveguide 10 for improving light output uniformity according to the present invention, the coupling component 11 in step 10011 includes a first grating 111, a second grating 112, and a third grating 113, wherein the grating direction of the first grating 111 is along the y-axis, the grating direction of the second grating 112 is at an angle of 60° to the y-axis, and the grating direction of the third grating 113 is at an angle of -60° to the y-axis.

[0114] Preferably, in step 10012 , the turning component 12 includes a fourth grating 121 and a fifth grating 122 , wherein the direction of the fourth grating 121 is the same as that of the third grating 113 , and the direction of the fifth grating 122 is the same as that of the second grating 112 .

[0115] Preferably, in step 1002, the outcoupling grating is implemented as a first two-dimensional grating 130, and the first two-dimensional grating 130 can be equivalent to three one-dimensional gratings, the three one-dimensional gratings including a sixth grating 131, a seventh grating 132 and an eighth grating 133, wherein the grating directions of the sixth grating 131, the seventh grating 132 and the eighth grating 133 are respectively along the y-axis and at 60° and -60° to the y-axis.

[0116] As a variation of the first embodiment of the projection method of the diffraction optical waveguide 10 for improving light output uniformity described in the present invention, in step 10011, the coupling component 11 is implemented as a second two-dimensional grating 140, and the second two-dimensional grating 140 can be equivalent to a ninth grating 141, a tenth grating 142 and an eleventh grating 143, wherein the grating direction of the ninth grating 141 is along the y-axis, the grating direction of the tenth grating 142 is 60° to the y-axis, and the grating direction of the eleventh grating 143 is -60° to the y-axis.

[0117] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations 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 any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0118] Those skilled in the art will appreciate that the embodiments of the present invention described above and shown in the accompanying drawings are intended to be illustrative only and are not intended to limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functional and structural principles of the present invention have been demonstrated and illustrated in the embodiments. Any variations or modifications may be made to the embodiments of the present invention without departing from the principles described.

Claims

1. A diffraction light waveguide for improving light uniformity, used for projecting at least one light beam, characterized in that: The diffraction optical waveguide for improving the uniformity of light output comprises an incoupling component and an outcoupling component, wherein the incoupling component is adapted to diffract the light of different viewing angles to the outcoupling component and uniformly cover the outcoupling component; wherein the coupling assembly comprises at least one coupling component and a turning component; wherein the coupling component comprises a first grating, a second grating and a third grating, wherein the first grating, the second grating and the third grating are respectively arranged along a first axis and grating directions at an angle of 60° and -60° to the first axis, and the second grating, the first grating and the third grating are sequentially arranged adjacent to each other; wherein the deflection component comprises a fourth grating and a fifth grating, wherein the fourth grating is disposed on the left side of the second grating and the fifth grating is disposed on the right side of the third grating, so that the light diffused from the second grating and the third grating can be deflected by the fourth grating and the fifth grating respectively; wherein the fourth grating and the third grating have the same direction and period, and the fifth grating and the second grating have the same direction and period, so that the direction of the light after passing through the second grating and being deflected by the fourth grating is parallel to the direction of the light after passing through the third grating and being deflected by the fifth grating, and is also parallel to the light after passing through the first grating; After the light is incident on the coupling-in component, part of the light coupled in by the first grating directly reaches the coupling-out component, part of the light coupled in by the second grating enters the fourth grating for further diffraction before reaching the coupling-out component, and part of the light coupled in by the third grating enters the fifth grating for further diffraction before reaching the coupling-out component.

2. The diffraction optical waveguide for improving light output uniformity according to claim 1, characterized in that: The coupling component is used to diffract incident light at different angles, and the light at different angles is diffracted and directed to different areas. 3 . The diffraction optical waveguide for improving light output uniformity according to claim 1 , wherein the outcoupling component is configured as a plurality of one-dimensional gratings or a first two-dimensional grating.

4. The diffraction optical waveguide for improving light output uniformity according to claim 1, further comprising at least a transparent parallel waveguide substrate, wherein the coupling-in component, the turning component and the coupling-out component are respectively arranged on the waveguide substrate.

5. The diffraction optical waveguide for improving light output uniformity according to claim 4, wherein the waveguide substrate has a front surface and a rear surface, and the coupling-in component, the turning component and the coupling-out component are respectively arranged on the front surface or the rear surface of the waveguide substrate. 6 . The diffractive optical waveguide for improving light output uniformity according to claim 4 , wherein the coupling-in component and the coupling-out component are respectively arranged on different surfaces of the waveguide substrate.

7. A method for projecting a diffraction light guide for improving light uniformity, for projecting a light beam, characterized in that: The method for projecting a diffraction light waveguide for improving light uniformity comprises the following steps: 1001: Projecting the light onto an incoupling component for diffraction; and 1002: The light diffracted by the coupling-in component can enter a coupling-out component for coupling out, and the light entering the coupling-in component can evenly cover the coupling-out component; Wherein said step 1001 further comprises the steps of: 10011: The coupling component comprises a coupling component and a turning component, the coupling component comprises a first grating, a second grating, and a third grating, the first grating, the second grating, and the third grating being respectively arranged along a first axis and grating directions at 60° and -60° to the first axis, and the second grating, the first grating, and the third grating being sequentially adjacently arranged; wherein the light is projected onto the coupling component for diffraction, and the light diffracted by the first grating, the second grating, and the third grating can be diffracted along a first axis, directions at 60° to the first axis, and directions at -60° to the first axis, respectively; and 10012: The deflection component includes a fourth grating and a fifth grating, the fourth grating is arranged on the left side of the second grating, and the fifth grating is arranged on the right side of the third grating. The fourth grating and the third grating have the same direction and period, and the fifth grating and the second grating have the same direction and period, so that the direction of the light after passing through the second grating and being deflected by the fourth grating is parallel to the direction of the light after passing through the third grating and being deflected by the fifth grating, and is parallel to the light after passing through the first grating; wherein part of the light coupled in by the first grating directly reaches the outcoupling component, part of the light coupled in by the second grating enters the fourth grating for further diffraction and then reaches the outcoupling component, and part of the light coupled in by the third grating enters the fifth grating for further diffraction and then reaches the outcoupling component.

8. The method for projecting a diffraction light guide for improving light uniformity according to claim 7, wherein: The coupling component is used to diffract incident light at different angles, and the light at different angles is diffracted and directed to different areas.

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