Augmented reality display apparatus and near-eye display device

Abstract

The application provides an augmented reality display device and a near-eye display device. The augmented reality display device comprises a waveguide substrate, an in-coupling grating, a turning grating and an out-coupling grating. The in-coupling grating is carried on the waveguide substrate, and couples light into the waveguide substrate. The grating vector of the in-coupling grating is a first vector K1. The turning grating is carried on the waveguide substrate, and expands the pupil of the light coupled into the waveguide substrate by the in-coupling grating. The grating vector of the turning grating is a second vector K2. The out-coupling grating is carried on the waveguide substrate, receives the light expanded by the turning grating, and couples the light out of the waveguide substrate. The grating vector of the out-coupling grating is a third vector K3. K1, K2 and K3 form a closed vector triangle, and when the augmented reality display device is used, the angle A between the direction of K3 and the horizontal direction X is in the range of -45°≤A≤45°. The augmented reality display device provided by the application can reduce or even avoid rainbow stripe phenomenon.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of augmented reality display technology, in particular to an augmented reality display device and a near-eye display device. BACKGROUND

[0002] With the development of technology, augmented reality (AR) display devices, such as AR glasses, need to see virtual images while seeing the external real world. The real scene and virtual information are integrated and complement each other, and are mutually "augmented". However, when a user uses the augmented reality display device, for example, wears the AR glasses, external environmental light will be dispersed into rainbow stripes and enter the human eye, so that the user sees rainbow stripes. This phenomenon is called rainbow stripe effect. When the user sees the rainbow stripes, the user's use experience is affected, and the user's eyes are even injured. SUMMARY

[0003] The first aspect of the present application provides an augmented reality display device, the augmented reality display device comprising:

[0004] a waveguide substrate;

[0005] an in-coupling grating carried on the waveguide substrate, configured to couple light into the waveguide substrate, and a grating vector of the in-coupling grating is a first vector K1;

[0006] a turning grating carried on the waveguide substrate, configured to expand pupils of the light coupled into the waveguide substrate by the in-coupling grating, wherein a grating vector of the turning grating is a second vector K2; and

[0007] an out-coupling grating carried on the waveguide substrate, configured to receive the light expanded by the turning grating and couple the light out of the waveguide substrate, and a grating vector of the out-coupling grating is a third vector K3, wherein the first vector K1, the second vector K2 and the third vector K3 form a closed vector triangle, and when the augmented reality display device is used, an angle A between a direction of the third vector K3 and a horizontal direction X is in a range of -45°≤A≤45°.

[0008] The augmented reality display device of the present application sets the out-coupling grating, so that when the augmented reality display device is used, the angle A between the direction of the third vector K3 and the horizontal direction X is in the range of -45°≤A≤45°, thereby reducing or even avoiding the rainbow stripe of the augmented reality display device when the augmented reality display device is used, and avoiding injury to the user's eyes.

[0009] The second aspect of the present application further provides an augmented reality display device, the augmented reality display device comprising:

[0010] waveguide substrate;

[0011] an in-coupling grating carried on the waveguide substrate for coupling light into the waveguide substrate, and a grating vector of the in-coupling grating being a first vector k1;

[0012] an out-coupling grating carried on the waveguide substrate for coupling light in the waveguide substrate out of the waveguide substrate, the out-coupling grating having a second vector k2 and a third vector k3, wherein the first vector k1, the second vector k2 and the third vector k3 form a closed vector triangle, and when the augmented reality display device is used, an angle between the second vector k2 and a horizontal direction X is less than or equal to 45°, and an angle between the third vector k3 and the horizontal direction X is less than or equal to 45°.

[0013] The augmented reality display device of the present application can reduce or even avoid rainbow fringes when the augmented reality display device is worn, and avoid damage to the user's eyes, by setting the out-coupling grating such that when the augmented reality display device is used, the angle between the second vector k2 and the horizontal direction X is less than or equal to 45°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 45°.

[0014] The third aspect of the present application provides a near-eye display device, comprising the augmented reality display device of any one of the second aspect and the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 A schematic diagram of an augmented reality display device according to an embodiment of the present application.

[0016] Figure 2 A schematic diagram of the augmented reality display device shown in Figure 1 A schematic diagram of light propagation of the augmented reality display device.

[0017] Figure 3 A schematic diagram of an application scenario of the augmented reality display device according to an embodiment of the present application.

[0018] Figure 4 A schematic diagram of the out-coupling grating and various parameters of the present application.

[0019] Figure 5 A schematic diagram of the waveguide substrate when the grating vector is vertically arranged and the waveguide substrate is directly opposite the sun.

[0020] Figure 6 A schematic diagram of the waveguide substrate when the grating vector is vertically arranged and the waveguide substrate is directly opposite the sun.

[0021] Figure 7Fig. 7 is a schematic diagram of the vector superposition when the grating vector is vertical and the waveguide substrate is completely side-on to the sun.

[0022] Figure 8 Fig. 8 is a schematic diagram of the vector superposition when the grating vector is vertical and the waveguide substrate is completely side-on to the sun. Figure 5

[0023] Figure 9 Fig. 9 is a schematic diagram of the vector superposition when the grating vector is vertical and the waveguide substrate is completely side-on to the sun. Figure 6

[0024] Figure 10 Fig. 10 is a schematic diagram of the vector superposition when the grating vector is vertical and the waveguide substrate is completely side-on to the sun. Figure 7

[0025] Figure 11 Fig. 11 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is directly facing the sun.

[0026] Figure 12 Fig. 12 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is at 45° to the sun.

[0027] Figure 13 Fig. 13 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is completely side-on to the sun.

[0028] Figure 14 Fig. 14 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is completely side-on to the sun. Figure 11

[0029] Figure 15 Fig. 15 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is completely side-on to the sun. Figure 12

[0030] Figure 16 Fig. 16 is a schematic diagram of the vector superposition when the grating vector is horizontal and the waveguide substrate is completely side-on to the sun. Figure 13

[0031] Figure 17 Fig. 17 is a schematic diagram of an augmented reality display device according to an embodiment of the application.

[0032] Figure 18 Fig. 18 is a schematic diagram of the light propagation of the augmented reality display device shown in Fig. 17. Figure 17

[0033] Figure 19 Fig. 19 is a schematic diagram of an augmented reality display device according to an embodiment of the application.

[0034] Figure 20 Fig. 20 is a schematic diagram of the light propagation of the augmented reality display device shown in Fig. 19. Figure 19

[0035] Fig. 21 is a schematic diagram of the structure of an out-coupling grating according to an embodiment of the application. Figure 21

[0036] Figure 22 ​​​​​​​​A perspective view of an augmented reality display device according to another embodiment of the present application.

[0037] Figure 23 A perspective view of an augmented reality display device according to another embodiment of the present application. Figure 22 A side view of the augmented reality display device in

[0038] Figure 24 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0039] Figure 25 A perspective view of an augmented reality display device according to another embodiment of the present application. Figure 24 A side view of the augmented reality display device in

[0040] Figure 26 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0041] Figure 27 A side view of a partial structure of the augmented reality display device in Figure 26

[0042] A perspective view of an augmented reality display device according to another embodiment of the present application. Figure 28

[0043] A side view of a partial structure of the augmented reality display device in Figure 29 Figure 28 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0044] Figure 30 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0045] Figure 31 A perspective view of a near-eye display device according to an embodiment of the present application.

[0046] Figure 32 A perspective view of a near-eye display device according to another embodiment of the present application.

[0047] Figure 33 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0048] Figure 34 A perspective view of an augmented reality display device according to another embodiment of the present application.

[0049] Figure 35 A side view of the augmented reality display device in Figure 34 A vector superimposition diagram of the augmented reality display device shown in

[0050] Figure 36 to Figure 39 A side view of the augmented reality display device in each of the embodiments.

[0051] ​Figure 40 A schematic diagram of an augmented reality display device according to another embodiment of the application.

[0052] Figure 41 A schematic diagram of an augmented reality display device according to yet another embodiment of the application.

[0053] Figure 42 A schematic diagram of a near-eye display device according to yet another embodiment of the application.

[0054] Figure 43 A schematic diagram of a near-eye display device according to yet another embodiment of the application.

[0055] Figure 44 A schematic diagram of a near-eye display device according to another embodiment of the application. DETAILED DESCRIPTION

[0056] The technical solutions in the embodiments of the present application will be apparently and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by one of ordinary skill in the art without any creative work fall within the scope of protection of the present application.

[0057] It should be noted that the term "embodiment" or "implementation" mentioned herein means that the specific features, structures or characteristics described in conjunction with the embodiment or implementation can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0058] The terms "first", "second", etc. appearing in the present application are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0059] Please refer to Figure 1 and Figure 2 , Figure 1 A schematic diagram of an augmented reality display device according to an embodiment of the present application; Figure 2 is Figure 1A schematic diagram of light propagation of an augmented reality display device is shown in FIG. 1. The present application provides an augmented reality (AR) display device 1. The AR display device 1 can be AR glasses or can be applied to a device with a windshield such as a car. The AR display device 1 is described in detail below. The AR display device 1 includes a waveguide substrate 110, a coupling-in grating 120, a turning grating 130, and a coupling-out grating 140. The coupling-in grating 120 is carried on the waveguide substrate 110 and is configured to couple light into the waveguide substrate 110, and a grating vector of the coupling-in grating 120 is a first vector K1. The turning grating 130 is carried on the waveguide substrate 110 and is configured to expand pupils of the light coupled into the waveguide substrate 110 by the coupling-in grating 120, and a grating vector of the turning grating 130 is a second vector K2. The coupling-out grating 140 is carried on the waveguide substrate 110 and is configured to receive the light expanded by the turning grating 130 and couple the light out of the waveguide substrate 110, and a grating vector of the coupling-out grating 140 is a third vector K3. The first vector K1, the second vector K2, and the third vector K3 form a closed vector triangle, and when the AR display device 1 is used, an angle A between the third vector K3 and a horizontal direction X is in a range of -45°≤A≤45°.

[0060] In Figure 2 The light is represented by dashed lines. When the AR display device 1 is used, the waveguide substrate 110 can be considered to be in an XY plane. The horizontal direction X is in the XY plane.

[0061] Some application scenarios of the AR display device 1 are described below. An important application scenario of the AR display device 1 of the present application is to solve the rainbow effect caused by outdoor sunlight. When the AR display device 1 is AR glasses, the AR display device 1 is used by being worn by a user. An application scenario of the AR display device 1 is described as follows. When the AR display device 1 is AR glasses, the user wears the AR display device 1 and stands outdoors, and the angle A between the third vector K3 and the horizontal direction X in the AR display device 1 of the present application is in a range of -45°≤A≤45°, which can reduce or even eliminate the rainbow effect caused by outdoor sunlight.

[0062] When the augmented reality display device 1 is applied to a device with a windshield such as a car, the augmented reality display device 1 can be arranged on the side of the windshield of the car close to the eyes of the user. The augmented reality display device 1 can be directly attached to the windshield, or can not be directly attached to the windshield and be arranged at a distance from the windshield. The eyes of the user view the situation outside the car, such as the road, pedestrians, etc. outside the car, through the augmented reality display device. The angle A between the third vector K3 and the horizontal direction X in the augmented reality display device 1 of the present application ranges from -45° to 45°, which can reduce or even eliminate the rainbow effect caused by sunlight outdoors.

[0063] The waveguide substrate 110, also known as an optical waveguide substrate, a dielectric optical waveguide substrate, or a waveguide substrate sheet, is a medium for guiding light to propagate therein. Optical waveguide substrates generally include two categories: one is an integrated optical waveguide substrate, including a planar (thin film) dielectric optical waveguide substrate and a strip-shaped dielectric optical waveguide substrate, which are usually part of an optoelectronic integrated device (or system), so they are called integrated optical waveguide substrates; the other is a cylindrical optical waveguide substrate, commonly known as an optical fiber (optical fiber). Generally, the waveguide substrate 110 is a guiding structure for transmitting light (optical frequency electromagnetic wave) composed of optically transparent medium (such as quartz glass). When light propagates in the waveguide substrate 110, total reflection occurs in the waveguide substrate 110, so that the light is confined in the waveguide substrate 110.

[0064] The waveguide substrate 110 in the present application is also known as a diffractive waveguide substrate. Due to its lightness, thinness, high penetration of external light, good color restoration, and large field of vision (FOV), it is considered as the best optical solution for consumer-level AR glasses.

[0065] The waveguide substrate 110 includes an outer surface 111 (see Figure 22 ) and an inner surface 112 (see ) arranged opposite to each other. The outer surface 111 refers to the surface facing away from the user when the augmented reality display device 1 is in use; the inner surface 112 refers to the surface close to the user when the augmented reality display device 1 is in use.

[0066] The in-coupling grating 120 is carried on the waveguide substrate 110, including the following cases: the in-coupling grating 120 is arranged on the inner surface 112 of the waveguide substrate 110, or the in-coupling grating 120 is arranged on the outer surface 111 of the waveguide substrate 110. The process of coupling light into the waveguide substrate 110 by the in-coupling grating 120 is also called light coupling-in.

[0067]

[0067] The pupil expansion refers to that, when the light is transmitted in the waveguide substrate 110, a part of the light is deflected by the action of the turning grating 130, and another part of the light is transmitted along the original propagation direction. The light transmitted along the original propagation direction is deflected multiple times after multiple actions of the turning grating 130, and multiple deflected light is generated. This phenomenon is called pupil expansion.

[0068] In the embodiment, the first vector K1, the second vector K2 and the third vector K3 form a closed vector triangle, so as to ensure that the augmented reality display device 1 can form an image.

[0069] The angle A between the third vector K3 and the horizontal direction X is in the range of -45°≤A≤45°, which can reduce or even eliminate the rainbow effect. The range of the angle A between the third vector K3 and the horizontal direction X, which can reduce or even eliminate the rainbow effect, will be described and explained later in combination with data.

[0070] The augmented reality refers to that the light of the image to be displayed generated by the image source 180 in the augmented reality display device 1 enters the waveguide substrate 110 through the in-coupling grating 120, and then is coupled out by the out-coupling grating 140 to be emitted to the human eye. The external environment light (such as sunlight outdoors or light generated by indoor lighting) can also be transmitted to the human eye through the in-coupling grating 120. Therefore, the user can view the image in the image source 180 and the image in the external environment, thereby realizing the augmented reality function of virtual and real combination. However, because the in-coupling grating 120 and the out-coupling grating 140 both have strong dispersion function, the external environment light will be dispersed into rainbow by the out-coupling grating 140, and mainly generated by -1 order reflection and -1 order transmission. When the user uses the augmented reality display device 1, for example, when the user wears the augmented reality display device 1, the -1 order reflected light cannot directly enter the human eye, and therefore has no effect on the user experience. However, the -1 order transmitted light may enter the human eye, so that the user sees the rainbow stripes, which is called rainbow effect. When the user sees the rainbow, the user experience is affected, and the user's eyes are even injured. It should be noted that whether the rainbow formed by -1 order transmission can enter the eyes of the user wearing the augmented reality display device 1 is related to the incident angle of the external environment light. For example, when the external environment light is incident on the out-coupling grating 140 at an angle of 50°, the rainbow formed by -1 order transmission has a large exit angle, and the diffracted light is more likely to deviate from the observation position of the user's eye. Even if it enters the user's eye, because the diffraction angle is large, the rainbow appears in the peripheral area of the field of view. When the external environment light is incident on the in-coupling grating 120 at an angle of 80°, the rainbow formed by -1 order transmission has a small exit angle, and the diffracted light is more likely to enter the human eye and is closer to the center of the field of view, which has a greater impact on the user.

[0071] When the user uses the augmented reality display device 1 outdoors, the sunlight outdoors as the external ambient light often passes through the rainbow stripes formed by the out-coupling grating 140 and is bright and dazzling, which directly leads to the fact that the augmented reality display device 1 on the market cannot be used outdoors well or even cannot be used outdoors at all. The present application mainly utilizes the principle of the incident vector of sunlight and vector superposition to convert the light of-1 order transmission into an evanescent wave or make it deviate outside the eye movement range, so as to achieve the purpose of relieving the rainbow stripes. Understandably, although the external ambient light is taken as sunlight in the present application for introduction, in other embodiments, the external ambient light also includes light generated by lighting lamps and the like.

[0072] In addition, according to the grating equation:

[0073] θ 衍射 =sin -1 (sin(θ 入射 )-λ / d) (Formula 1)

[0074] Wherein, λ is the wavelength, and d is the grating period. It can be known from the grating equation of formula (1) that the longer the wavelength of the light is, the larger the diffraction angle is. Since the wavelength of blue light is smaller than that of red light, the diffraction angle of blue light is smaller than that of red light. Therefore, when the rainbow stripes appear, the blue light appears in the center of the field of view observed by the user's eye due to the small diffraction angle, and the red light appears in the peripheral region of the field of view due to the larger diffraction angle.

[0075] Please refer to Figure 3 , Figure 3 the application scenario schematic diagram of the augmented reality display device provided by an embodiment of the present application. The judgment on whether the rainbow stripes can be emitted into the human eye is as follows. As shown in the schematic diagram, AA' is the outermost peripheral region of the out-coupling grating 140, and the length thereof is defined as d. BB' is the internal region of the out-coupling grating 140. When the augmented reality display device 1 is worn, the distance from the waveguide substrate 110 to the eye movement range is referred to as the eye view distance, and the length thereof is defined as l. The eye movement range refers to the observation region in which the human eye can see a complete and clear field of view, the geometric center of the eye movement range is aligned with the geometric center of the out-coupling grating 140, and the length thereof is defined as m. Assuming that a light beam is incident from the A point, diffracts to the edge C' of the eye movement range through the out-coupling grating 140, and the included angle between the diffracted light and the normal line is θ, the formula is obtained according to the geometric relationship:

[0076]

[0077] From Figure 3It is easy to see that when the diffraction angle of light is greater than θ, the light will be outside the diffraction range and cannot be observed by the human eye. When the diffraction angle of light is less than θ, the light will be captured by the human eye because it enters the eye movement range. In summary, the smaller θ is, the more difficult it is for the rainbow pattern to enter the human eye, and therefore the smaller its impact on the user experience. When θ is larger, the rainbow pattern effect will become more obvious. That is to say, while keeping the eye movement range and visual distance constant, the smaller the area of ​​the coupling grating 140 or the smaller the period of the coupling grating 140, the weaker the effect of the rainbow pattern will be. Finally, the relationship between FOV, the size d of the coupling grating 140, and the size m of the eye movement range can be derived through geometric relationships:

[0078] d = m + l * tan(FOV / 2) * 2 (Formula 3)

[0079] Before delving into the technical principles of this application, let's first discuss some common variables in grating diffraction. Please refer to... Figure 4 , Figure 4 This is a schematic diagram of the coupling grating and its various parameters according to this application. As shown in the schematic diagram of this embodiment, the direction of the grating vector K3 of the coupling grating 140 is consistent with the positive direction of the X-axis, and the angle between the plane formed by the incident direction of sunlight and the Z-axis and the X-axis is... This is called the azimuth angle, and the angle θ between the direction of solar incidence and the Z-axis is called the angle of incidence.

[0080] A schematic diagram of sunlight illuminating the augmented reality display device 1 when the grating vector of the coupled grating 140 is in the vertical direction (i.e., the grating vector direction is parallel to the Y direction) is shown below. Figure 5 to Figure 7 As shown below, in conjunction with Figure 5 to Figure 7 The discussion covers three scenarios where the waveguide substrate 110 faces the sun at different angles, thus affecting the incident angle θ and azimuth angle of the sunlight relative to the coupling grating 140. In this situation. It should be noted that, in Figure 5 to Figure 7 The specific structure of the coupling grating 140 is not shown in the figure.

[0081] Figure 5 The diagram (i.e., Case 1) illustrates the situation when the waveguide substrate 110 faces the sun, i.e., the sunlight is located in the XZ plane, and the azimuth angle at this time is... The angle of incidence θ of sunlight relative to the coupling grating 140 is equal to the solar altitude angle.

[0082] Figure 6 The diagram (i.e., Case 2) illustrates the case where the waveguide substrate 110 is tilted at 45° towards the sun. This means the plane formed by the sunlight and the normal direction (Z-axis) of the waveguide substrate 110 makes an angle of 45° with the X-axis. Therefore, the azimuth angle... The angle of incidence of sunlight relative to the coupling grating 140 is θ = solar altitude angle.

[0083] Figure 7 Case 3 illustrates the situation where the waveguide substrate 110 is completely sideways to the sun, i.e., the sunlight is in the XY plane, and the azimuth angle at this time is... - Solar altitude angle, the angle of incidence of sunlight relative to the coupling grating 140 is θ = 90°.

[0084] Please refer to the following: Figure 8 to Figure 10 , Figure 8 for Figure 5 A schematic diagram of vector superposition in the image; Figure 9 for Figure 6 A schematic diagram of vector superposition in the image; Figure 10 for Figure 7 A schematic diagram illustrating the vector superposition in the image. It should be noted that... Figure 8 to Figure 10 The vector superposition in the diagram is performed in the k-domain, where Ks is the incident vector of sunlight, K3 is the grating vector of the coupling grating, and Kd is the outgoing vector of sunlight. The larger the incident angle or diffraction angle of sunlight, the larger the magnitude of the corresponding incident vector Ks. When the magnitude of the outgoing vector Kd is large, its outgoing angle is also large, and the rainbow pattern produced by diffraction is more likely to deviate from the eye movement range. When the magnitude of the outgoing vector Kd is small, the rainbow pattern produced by diffraction is more likely to appear within the eye movement range and more likely to appear at the center of the field of view. In other words, the longer the length of the outgoing vector Kd, the greater the influence of the rainbow pattern; the shorter the length of the outgoing vector Kd, the smaller the influence of the rainbow pattern. The vector superposition of the three cases is analyzed in detail below.

[0085] For case 1, due to the azimuth angle The angle is 0°, meaning the incident vector Ks of the sunlight and the grating vector K3 (i.e., the third vector K3) of the coupled grating are parallel. At this angle, the length of the outgoing vector Kd of the sunlight is the smallest, and it is easiest to produce rainbow patterns.

[0086] For case 2, its azimuth angle At 45°, the length of the solar radiation vector Kd is longer than in case 1, thus the effect of the rainbow pattern will be weakened.

[0087] For case 3, its azimuth angle The magnitude is relatively larger, therefore the effect of the rainbow pattern will be further reduced. Based on calculations, we can obtain the following relationship between the magnitude of the emitted vector and the azimuth angle:

[0088]

[0089] As can be seen from formula (4), the azimuth angle The closer the angle approaches 90°, the more difficult it is for the augmented reality display device 1 to produce rainbow fringes.

[0090] The grating vector of the out-coupling grating 140 is vertically arranged, and the case is calculated in detail as follows. First, according to formula (2), it can be calculated that when the diffraction angle of the -1 order transmitted light of the out-coupling grating 140 is greater than 40°, it will deviate from the eye movement range, and thus cannot be captured by the human eye. The period of the out-coupling grating 140 is set to 380 nm, and the diffraction angles of the light with wavelengths of 460 nm (blue light), 522 nm (green light), and 620 nm (red light) in the diffracted light are analyzed. For case 1, the calculation results when the azimuth angle of the sunlight is 0° are as follows.

[0091] Table 1

[0092]

[0093] The diffraction angles of the blue light, green light, and red light at different incident angles when the azimuth angle of the sunlight is 0° are shown in Table 1. As can be seen from Table 1, when the solar elevation angle is greater than 35°, the human eye can see the blue diffracted light (i.e., blue light); when the solar elevation angle is greater than 50°, the human eye can see the green diffracted light (i.e., green light); and when the solar elevation angle is greater than 85°, the human eye can see the red diffracted light (i.e., red light); that is, as the diffraction angle gradually increases, the green light and the red light gradually appear, and the blue light is closer and closer to the center of the field of view. As can be seen from Table 1, as the incident angle increases, the rainbow fringe phenomenon becomes more obvious.

[0094] For case 2, the calculation results when the azimuth angle of the sunlight is 45° and the solar elevation angle is 0° are shown in Table 2.

[0095] Table 2

[0096]

[0097]

[0098] The diffraction angles of the blue light, green light, and red light at different incident angles when the azimuth angle of the sunlight is 45° are shown in Table 2, and according to the calculation results, it can be seen that in this case, the human eye cannot observe the rainbow fringes.

[0099] For case 3, the calculation results when the azimuth angle of the sunlight is 45° and the solar elevation angle is 0° are shown in Table 3.

[0100] Table 3

[0101] ​​

[0102]

[0103] As can be seen from the calculation results in Table 3, the results for the rainbow pattern in scenario 3 are the same as those in scenario 1. When the solar altitude angle is greater than 35°, the human eye can see blue diffracted light (i.e., blue light); when the solar altitude angle is greater than 50°, the human eye can see green diffracted light (i.e., green light); and when the solar altitude angle is greater than 85°, the human eye can see red diffracted light (i.e., red light). In other words, as the diffraction angle gradually increases, green and red light gradually become visible, and blue light gets closer and closer to the center of the field of view. It is easy to see from Table 3 that the rainbow pattern becomes more pronounced as the incident angle increases.

[0104] The following describes the case where the grating vector is in the horizontal direction (parallel to the X direction). A schematic diagram of the augmented reality display device 1 illuminated by sunlight when the grating vector is in the horizontal direction is shown below. Figure 11 to Figure 13 As shown below, in conjunction with Figure 11 to Figure 13 The discussion covers three scenarios where the waveguide substrate 110 faces the sun at different angles, thus affecting the incident angle θ and azimuth angle of the sunlight relative to the coupling grating 140. The situation.

[0105] Figure 11 The diagram (i.e., case 1') illustrates the situation where the waveguide substrate 110 faces the sun, meaning the sunlight is located in the XZ plane, and the azimuth angle at this time is... The angle of incidence of sunlight relative to the coupling grating 140 is θ = solar altitude angle.

[0106] Figure 12 In the middle (i.e., case 2'), it is shown that the waveguide substrate 110 is tilted at 45° towards the sun, that is, the plane formed by the sunlight and the normal direction (Z-axis) of the waveguide substrate 110 makes an angle of 45° with the X-axis, therefore the azimuth angle is... The angle of incidence of sunlight relative to the grating is θ = solar altitude angle.

[0107] Figure 13 The diagram (i.e., case 3') illustrates the situation where the waveguide substrate 110 is completely sideways to the sun, meaning the sunlight is in the XY plane, and the azimuth angle at this time is... =Solar altitude angle, the incident angle of sunlight relative to the coupling grating 140 is θ = 90°.

[0108] Please refer to the following: Figure 14 to Figure 16 , Figure 14 for Figure 11 A schematic diagram of vector superposition in the image; Figure 15 for Figure 12 A schematic diagram of vector superposition in the image;Figure 16 for Figure 13 A schematic diagram illustrating the vector superposition in the image. It should be noted that... Figure 14 to Figure 16 The vector superposition in the diagram is performed in the k-domain, where Ks is the incident vector of sunlight, K3 is the grating vector of the coupling grating, and Ks is the outgoing vector of sunlight. The larger the incident angle or diffraction angle of sunlight, the larger the magnitude of the corresponding incident vector Ks. When the magnitude of the outgoing vector Kd is large, its outgoing angle is also large, and the rainbow pattern produced by diffraction is more likely to deviate from the eye movement range. When the magnitude of the outgoing vector Kd is small, the rainbow pattern produced by diffraction is more likely to appear within the eye movement range and more likely to appear at the center of the field of view. In other words, the longer the length of the outgoing vector Kd, the greater the influence of the rainbow pattern; the shorter the length of the outgoing vector Kd, the smaller the influence of the rainbow pattern. The vector superposition in these three cases is analyzed in detail below.

[0109] For case 1', due to the azimuth angle The angle is 90°, meaning the incident vector Ks of the sunlight is perpendicular to the grating vector K3 (i.e., the third vector K3) of the coupled grating. At this angle, the length of the outgoing vector Kd of the sunlight is the largest, and it is least likely to produce rainbow patterns.

[0110] For case 2', its azimuth angle At 45°, the length of the solar radiation vector Kd is longer than in case 1, thus the effect of the rainbow pattern will be weakened.

[0111] For case 3', its azimuth angle The rainbow pattern is related to the solar altitude angle; the higher the solar altitude angle, the weaker the rainbow pattern becomes, thus further reducing its influence.

[0112] The following is a detailed calculation of the case where the grating vector is set horizontally. According to formula (2), when the diffraction angle of the -1st order transmitted light through the coupling grating 140 is greater than 40°, it will deviate from the eye movement range and therefore cannot be captured by the human eye. The period of the coupling grating 140 is set to 380nm, and the diffraction angles of the light with wavelengths of 460nm (blue light), 522nm (green light), and 620nm (red light) in the diffracted light are analyzed. For case 1', the calculation results when the incident azimuth angle of the sunlight is 0° are shown in the table below.

[0113] Table 1'

[0114]

[0115]

[0116] The diffraction angles of blue, green and red light at different incident angles when the sun rays are at an azimuth angle of 90° are shown in Table 1'. As can be seen from Table 1', in this case, the human eye cannot observe the rainbow fringes.

[0117] For case 2', the incident azimuth angle of the sun rays is The calculation results when the incident azimuth angle of the sun rays is

[0118] Table 2'

[0119]

[0120] The diffraction angles of blue, green and red light at different incident angles when the sun rays are at an azimuth angle of 45° are shown in Table 2'. As can be seen from the calculation results, in this case, the human eye cannot observe the rainbow fringes.

[0121] For case 3', the incident azimuth angle of the sun rays is The calculation results when the incident azimuth angle of the sun rays is

[0122] Table 3'

[0123]

[0124] As can be seen from the calculation results in Table 3', in case 3', the human eye can only observe the rainbow fringes when the solar elevation angle is less than 30°. Specifically, when the solar elevation angle is less than 30°, the human eye can see the blue diffraction light (i.e. blue light); when the solar elevation angle is less than 25°, the human eye can see the green diffraction light (i.e. green light); and when the solar elevation angle is less than 5°, the human eye can see the red diffraction light (i.e. red light).

[0125] Table 4 summarizes the rainbow fringe performance in the three cases when the grating vector is placed horizontally or vertically.

[0126] Table 4

[0127]

[0128] In daily life, the solar elevation angle is generally less than 30° only in the morning or evening. However, at this time, the brightness of the sun rays is relatively small, so the rainbow fringes caused by the sun rays are also relatively weak. At noon, the solar elevation angle is relatively large, and the brightness of the sun rays is relatively high. Therefore, the design of placing the grating vector horizontally can effectively alleviate the influence of the rainbow fringes.

[0129] According to the above analysis, it can be known that the rainbow phenomenon in outdoor use can be obviously alleviated by optimizing the placing direction of the grating vector (i.e., the third vector K3) of the coupling-out grating 140. The effect is best when the grating vector of the coupling-out grating 140 is placed horizontally (i.e., the angle between the third vector K3 of the coupling-out grating and the horizontal direction X is 0°), and the influence of the rainbow phenomenon on the grating vector is far less than that when the grating vector is placed vertically. In other words, when the angle A between the direction of the grating vector K3 of the coupling-out grating 140 and the horizontal direction X ranges from -45° to 45°.

[0130] The embodiment of the present application utilizes the formation mechanism of the rainbow phenomenon, and by ingenious design, the -1 order transmitted light of the coupling-out grating 140 is deviated from the eye movement range as much as possible, so as to alleviate the rainbow phenomenon. The embodiment of the present application does not increase the complexity of the process, and does not affect the observation of the ambient light by the human eye. By utilizing the vector superposition principle of light, the rainbow phenomenon is changed into an evanescent wave or deviated from the eye movement range as much as possible, so as to achieve the purpose of alleviating the rainbow phenomenon into the human eye of the user using the augmented reality display device.

[0131] In an embodiment, the angle A between the direction of the third vector K3 and the horizontal direction X ranges from -30° to 30°. When the angle A between the third vector K3 and the horizontal direction X ranges from -30° to 30°, it is relatively difficult to appear the rainbow phenomenon even in the morning or evening. Therefore, when the angle A between the third vector K3 and the horizontal direction X ranges from -30° to 30°, the -1 order transmitted light of the coupling-out grating 140 can be deviated from the eye movement range more effectively, so as to more effectively alleviate the rainbow phenomenon.

[0132] It should be noted that in actual application, the selection of the range of the angle A between the third vector K3 and the horizontal direction X takes into account the alleviation of the rainbow phenomenon and the imaging factors of the augmented reality display device.

[0133] Please refer to Figure 17 and Figure 18 , Figure 17 a schematic diagram of an augmented reality display device provided by an embodiment of the present application; Figure 18 is Figure 17 a light propagation schematic diagram of the augmented reality display device shown in

[0134] Figure 17The waveguide architecture composed of the in-coupling grating, the turning grating, the out-coupling grating and the waveguide substrate is shown in FIG. 1. The profile of the in-coupling grating can be any one of blazed grating, slanted grating, binary grating, photonic crystal, etc. The profile of the turning grating can be binary grating, photonic crystal, etc. The profile of the out-coupling grating can be any one of blazed grating, slanted grating, binary grating, photonic crystal, etc. If the in-coupling grating vector (i.e. the first vector) K1 is distributed along the vertical direction, the angle between the turning grating vector (i.e. the second vector) K2 and the vertical direction is According to the vector superposition principle, the out-coupling grating vector (i.e. the third vector) K3 parallel to the horizontal direction can be obtained. If the angle between the out-coupling grating vector K1' and the vertical direction is any angle θ, the angle between the turning grating vector K2' and the in-coupling grating vector K1' becomes any angle By superimposing the grating vectors K1' and K2', the out-coupling grating vector K3' parallel to the horizontal direction can also be obtained. Here, the angle θ can take any value from -45° to +45°, where the counterclockwise rotation relative to the coordinate axis X is positive and the clockwise rotation is negative. For Then, only the following condition needs to be satisfied to form a closed vector triangle and make the out-coupling grating vector K3' parallel to the horizontal direction. According to the foregoing derivation, it can be known that the augmented reality display device of this waveguide substrate architecture can effectively avoid the rainbow phenomenon caused by sunlight in outdoor environment.

[0135] In this embodiment, the direction of the grating vector of the in-coupling grating is perpendicular to the horizontal direction X, i.e. the first vector K1 is perpendicular to the horizontal direction X. In other words, the angle between the first vector K1 of the in-coupling grating and the vertical direction Y is zero.

[0136] Please refer to Figure 19 and Figure 20 , Figure 19 the schematic diagram of the augmented reality display device provided in an embodiment of the present application; Figure 20 is Figure 19 the schematic diagram of the light propagation of the augmented reality display device shown in FIG. 1. The grating vector of the out-coupling grating in this embodiment is placed at a certain angle with the horizontal direction X.

[0137] Figure 19 and Figure 20The waveguide structure is shown in which the grating vector of the out-coupling grating is set at an angle with the horizontal direction. The profile of the in-coupling grating can be any one of blazed grating, slanted grating, binary grating, photonic crystal, etc. The profile of the turning grating can be binary grating, photonic crystal, etc. The profile of the out-coupling grating can be any one of blazed grating, slanted grating, binary grating, photonic crystal, etc. If the angle between the in-coupling grating vector (i.e. the first vector) K1 and the vertical direction Y is any angle α, the angle between the turning grating vector (i.e. the second vector) K2 and the in-coupling grating vector K1 becomes any angle By superimposition of the vectors K1 and K2, the grating vector K3 can also be obtained, and the angle between K3 and the horizontal direction is β. The angle between the in-coupling grating vector (i.e. the first vector) K1 and the vertical direction Y is any angle α, i.e. in the present embodiment, the angle between the grating vector of the in-coupling grating and the vertical direction Y is α. Here, the angle α can take any value from -45° to +45°, and is positive counterclockwise and negative clockwise relative to the coordinate axis. As shown in the figure, the angle α is negative, and the angle β is also negative. For As long as a closed vector triangle can be formed, and the angle β between the out-coupling grating vector K3 and the horizontal direction is controlled within ±45°. Although the grating vector K3 of the out-coupling grating is set at an angle with the horizontal direction X, its performance in suppressing rainbow stripes is not as good as that of the out-coupling grating vector (i.e. the third vector) K3 placed completely horizontally, but it can still suppress the rainbow stripe effect for most angles of incidence. The smaller the absolute value of the angle β, the more obvious the suppression effect of the rainbow stripes will be, and vice versa.

[0138] Please refer to Figure 3 and Figure 21 , Figure 21 The structure schematic diagram of the out-coupling grating provided in an embodiment. The out-coupling grating 140 comprises a plurality of out-coupling units 141 arranged at intervals and periodically, and the period of the out-coupling grating 140 is less than or equal to 450 nm.

[0139] Generally, for a one-dimensional grating, the grating includes a plurality of units arranged periodically and spaced apart, and the direction of the periodic arrangement of the plurality of units is the grating vector. For the out-coupling grating 140, the direction of the periodic arrangement of the plurality of out-coupling units 141 is the grating vector of the out-coupling grating 140. For a two-dimensional grating, the two-dimensional grating has two grating vectors, in other words, the two-dimensional grating includes a plurality of units arranged periodically in one direction, and includes a plurality of units arranged periodically in another direction. The one direction of the periodic arrangement of the units is one of the grating vectors, and the other direction of the periodic arrangement of the units is the other grating vector. For the out-coupling grating 140 being a two-dimensional grating, the one direction of the periodic arrangement of the out-coupling grating units in the two-dimensional grating is one of the grating vectors, and the other direction of the periodic arrangement of the out-coupling units in the two-dimensional grating is the other grating vector.

[0140] As can be seen from Figure 3 When the diffraction angle of the light is greater than θ, the light cannot be observed by the human eye because it is out of the diffraction range, and when the diffraction angle of the light is less than θ, the light can be captured by the human eye because it is in the eye movement range. In summary, the smaller θ is, the more difficult it is for the rainbow fringe to enter the human eye, and thus the smaller the impact on the user experience will be, and the larger θ is, the more obvious the rainbow fringe effect will be. That is, on the basis of keeping the eye movement range and the eye viewing distance unchanged, the smaller the area of the out-coupling grating 140 or the smaller the period of the out-coupling grating 140, the weaker the impact of the rainbow fringe will be.

[0141] In this embodiment, the period of the out-coupling grating 140 is less than or equal to 450 nm, so that the impact of the rainbow fringe is weaker, and the smaller the period of the out-coupling grating 140 is, the weaker the impact of the rainbow fringe is. In one embodiment, the period of the out-coupling grating 140 is equal to 380 nm.

[0142] In one embodiment, the area of the out-coupling grating 140 is a rectangle, wherein the side length of the rectangle satisfies:

[0143] d = m + l*tan(FOV / 2)*2 (Formula 5)

[0144] wherein d is the side length of the rectangle, m is the eye movement range of the user, l is the distance from the eye of the user to the waveguide, and FOV is the field of view angle of the augmented reality display system.

[0145] Specifically, in an embodiment, d is the long side of the rectangle, and d satisfies formula (5); in another embodiment, d is the short side of the rectangle, and d satisfies formula (5); in yet another embodiment, both the long side d1 of the rectangle and the short side d2 of the rectangle satisfy formula (5), that is, d1 = m + l*tan(FOV / 2)*2 and d2 = m + l*tan(FOV / 2)*2.

[0146] In an embodiment, the period of the out-coupling grating 140 is the same as the period of the in-coupling grating 120.

[0147] The period of the out-coupling grating 140 is the same as the period of the in-coupling grating 120, so that the preparation of the out-coupling grating 140 and the in-coupling grating 120 is more convenient in the process.

[0148] In another embodiment, in the actual design process, the profile of the out-coupling grating 140 is the same as the profile of the in-coupling grating 120, which can also make the preparation of the out-coupling grating 140 and the in-coupling grating 120 more convenient. In another embodiment, the period of the out-coupling grating 140 is the same as the period of the in-coupling grating 120, and the profile of the out-coupling grating 140 is the same as the profile of the in-coupling grating 120, and the height of the out-coupling grating 140 is different from the height of the in-coupling grating 120. The period of the out-coupling grating 140 is the same as the period of the in-coupling grating 120, and the profile of the out-coupling grating 140 is the same as the profile of the in-coupling grating 120, and the height of the out-coupling grating 140 is different from the height of the in-coupling grating 120, and the out-coupling grating 140 and the in-coupling grating 120 are a pair of conjugate systems.

[0149] It can be understood that, in other embodiments, the period of the out-coupling grating 140 can also be different from the period of the in-coupling grating 120. The profile of the out-coupling grating 140 can also be different from the profile of the in-coupling grating 120.

[0150] The augmented reality display device 1 provided by the embodiments of the present application does not have special requirements for the profile of the out-coupling grating 140, and the profile of the out-coupling grating 140 can be any one of a blazed grating, a tilted grating, a binary grating, and a photonic crystal.

[0151] The position relationship of the in-coupling grating 120, the turning grating 130, and the out-coupling grating 130 relative to the waveguide substrate 110 will be introduced below. It should be noted that in the following figures, only the position relationship of the in-coupling grating 120, the turning grating 130, and the out-coupling grating 130 relative to the waveguide substrate 110 is shown, and the profile and specific structure of the in-coupling grating 120, the turning grating 130, and the out-coupling grating 140 are not shown.

[0152] Referring to Figure 22 to Figure 29 , Figure 22 a perspective view of an augmented reality display device according to another embodiment of the present application is shown; Figure 23 a side view of the augmented reality display device in Figure 22 In Figure 22 and Figure 23 , the in-coupling grating 120, the turning grating 130 and the out-coupling grating 140 are disposed on the same side of the waveguide substrate 110 and on the inner surface 112 of the waveguide substrate 110.

[0153] Figure 24 a perspective view of an augmented reality display device according to another embodiment of the present application is shown; Figure 25 a side view of the augmented reality display device in Figure 24 In Figure 24 and Figure 25 , the in-coupling grating 120, the turning grating 130 and the out-coupling grating 140 are disposed on the same side of the waveguide substrate 110 and on the outer surface 111 of the waveguide substrate 110.

[0154] Figure 26 a perspective view of an augmented reality display device according to another embodiment of the present application is shown; Figure 27 a side view of a partial structure of the augmented reality display device in Figure 26 In Figure 26 and Figure 27 , the in-coupling grating 120 and the turning grating 130 are disposed on the same side of the waveguide substrate 110, the out-coupling grating 140 is disposed on the other side of the waveguide substrate 110, and the in-coupling grating 120 and the turning grating 130 are disposed on the inner surface 112 of the waveguide substrate 110, and the out-coupling grating 140 is disposed on the outer surface 111 of the waveguide substrate 110.

[0155] Figure 28 a perspective view of an augmented reality display device according to another embodiment of the present application is shown; Figure 29 a side view of a partial structure of the augmented reality display device in Figure 28 In Figure 28 and Figure 29 , the in-coupling grating 120 and the turning grating 130 are disposed on one side of the waveguide substrate 110, the out-coupling grating 140 is disposed on the other side of the waveguide substrate 110, and the in-coupling grating 120 and the turning grating 130 are disposed on the outer surface 111 of the waveguide substrate 110, and the out-coupling grating 140 is disposed on the inner surface 112 of the waveguide substrate 110.

[0156] The above arrangement of the in-coupling grating 120, the turning grating 130, the out-coupling grating 140 and the waveguide substrate 110 makes it easier to arrange the in-coupling grating 120, the out-coupling grating 140 and the waveguide substrate 110. It should be noted that the in-coupling grating 120, the turning grating 130 and the out-coupling grating 140 and the waveguide substrate 110 can be arranged in any way, as long as the angle between the out-coupling grating vector and the horizontal direction is controlled to suppress the rainbow effect.

[0157] In an embodiment, the out-coupling grating 140 and the waveguide substrate 110 are integrated.

[0158] The out-coupling grating 140 can be formed on a substrate by a stamping technique or the like, i.e., the portion of the substrate that is stamped constitutes the out-coupling grating 140, and the portion of the substrate that is not stamped constitutes the waveguide substrate 110, so the out-coupling grating 140 and the waveguide substrate 110 are integrated.

[0159] In another embodiment, the in-coupling grating 120 and the waveguide substrate 110 are also integrated. Specifically, the out-coupling grating 140 can be formed on a substrate by a stamping technique or the like, i.e., the portion of the substrate that is stamped constitutes the in-coupling grating 120, and the portion of the substrate that is not stamped constitutes the waveguide substrate 110, so the in-coupling grating 120 and the waveguide substrate 110 are integrated.

[0160] In another embodiment, the in-coupling grating 120, the out-coupling grating 140 and the waveguide substrate 110 are integrated. Specifically, the in-coupling grating 120 and the out-coupling grating 140 can be formed on a substrate by a stamping technique or the like, i.e., the portion of the substrate that is stamped constitutes the in-coupling grating 120 and the out-coupling grating 140, and the portion of the substrate that is not stamped constitutes the waveguide substrate 110, so the in-coupling grating 120, the out-coupling grating 140 and the waveguide substrate 110 are integrated.

[0161] Please refer to Figure 30 , Figure 30 A schematic diagram of an augmented reality display device according to another embodiment of the present application is shown. In this embodiment, the augmented reality display device 1 includes a waveguide substrate 110, an in-coupling grating 120 and an out-coupling grating 140. In addition, the augmented reality display device 1 also includes a polarizer 150. The waveguide substrate 110, the in-coupling grating 120 and the out-coupling grating 140 are described above and will not be repeated here. The light emitted by the polarizer 150 enters the out-coupling grating 140, wherein the polarization direction of the polarizer 150 is the horizontal direction X.

[0162] The polarization direction of the reflected light rays of the sunlight rays via the reflection of the glass in the environment is generally along the Y-axis direction. The polarizer 150 with the polarization direction of the horizontal direction X can filter out the reflected light rays with the polarization direction along the Y-axis direction in the environment, and further avoid the generation of rainbow stripes.

[0163] The waveguide substrate 110 includes an outer surface 111 and an inner surface 112 arranged oppositely. In the embodiment, the polarizer 150 and the out-coupling grating 140 are both arranged on the outer surface 111 of the waveguide substrate 110, and the polarizer 150 is arranged away from the waveguide substrate 110 compared with the out-coupling grating 140.

[0164] Further, in the embodiment, the augmented reality display device 1 further includes a protective sheet 210. The material of the protective sheet 210 can be, but is not limited to, glass, plastic, etc. The protective sheet 210 is arranged on the surface of the polarizer 150 away from the out-coupling grating 140, for protecting the polarizer 150 from being damaged. It can be understood that, in another embodiment, the augmented reality display device 1 can not include the protective sheet 210.

[0165] In the schematic diagram of the embodiment, the augmented reality display device 1 including the polarizer 150 and the protective sheet 210 is combined into the augmented reality display device 1 provided in the foregoing embodiment. It can be understood that the augmented reality display device 1 including the polarizer 150 and the protective sheet 210 can also be combined into other embodiments, for example, combined into the embodiment in which the out-coupling grating 120 is arranged on the inner surface 112.

[0166] Please refer to Figure 31 , Figure 31 A schematic diagram of an augmented reality display device provided in another embodiment of the present application. In the embodiment, the augmented reality display device 1 further includes a polarizer 150. The light rays emitted by the polarizer 150 enter the out-coupling grating 140, wherein the polarization direction of the polarizer 150 is the horizontal direction X. In the embodiment, the waveguide substrate 110 includes an outer surface 111 and an inner surface 112 arranged oppositely. The polarizer 150 is arranged on the outer surface 111 of the waveguide substrate 110, and the out-coupling grating 140 is arranged on the inner surface 112 of the waveguide substrate 110.

[0167] Further, in the present embodiment, the augmented reality display device 1 further comprises a protective sheet 210, which can be made of, but not limited to, glass, plastic, etc. The protective sheet 210 is arranged on the surface of the polarizer 150 away from the waveguide substrate 110, for protecting the polarizer 150 from damage. It can be understood that in another embodiment, the augmented reality display device 1 can not comprise the protective sheet 210.

[0168] In an embodiment, the polarizer 150 is a coated polarizer. In other words, the polarizer 150 is a polarizer 150 formed by a coating process. When the polarizer 150 and the out-coupling grating 140 are both arranged on the outer surface 111 of the waveguide substrate 110, and the polarizer 150 is arranged away from the waveguide substrate 110 compared to the out-coupling grating 140, the polarizer 150 is a film coated on the outer surface 111 of the out-coupling grating 140. When the polarizer 150 is arranged on the outer surface 111 of the waveguide substrate 110, and the out-coupling grating 140 is arranged on the inner surface 112 of the waveguide substrate 110, the polarizer 150 is a film coated on the outer surface 111 of the waveguide substrate 110. In another embodiment, the polarizer 150 is a single-piece polarizer 150, which is bonded to the out-coupling grating 140 or the waveguide substrate 110 by an adhesive or the like.

[0169] The polarizer 150 is a coated polarizer, which can make the polarizer 150 thinner and easier to manufacture.

[0170] Please refer to Figure 32 , Figure 32 A schematic diagram of a near-eye display device according to an embodiment of the present application is shown. The near-eye display device 2 comprises the augmented reality display device 1 according to any of the preceding embodiments.

[0171] In an embodiment, the near-eye display device 2 further comprises a wearing frame 160. The wearing frame 160 has two spaced-apart window regions 161, at least one of the two window regions 161 is provided with the out-coupling grating 140.

[0172] When one of the two window regions 161 is provided with the out-coupling grating 140, the one window region 161 can make the human eye see virtual images, and the in-coupling grating 120 region itself can also transmit ambient light, so that one window region 161 can achieve the effect of augmented reality. When both of the two window regions 161 are provided with the out-coupling grating 140, both of the two window regions 161 can achieve the effect of augmented reality. In the schematic diagram of the present embodiment, both of the two window regions 161 are provided with the out-coupling grating 140 as an example.

[0173] Please refer to Figure 33 , Figure 33 The schematic diagram of the near-eye display device provided in another embodiment of the present application. The near-eye display device 2 further comprises a wearing frame 160, a wearing bracket 170, an image source 180 and an optical lens assembly 190. The wearing bracket 170 is connected to the wearing frame 160. The image source 180, also referred to as a projection light machine, is arranged on one side of the waveguide substrate 110 and used to generate light according to an image to be displayed. The optical lens assembly 190 is arranged between the image source 180 and the in-coupling grating 120 and used to project the light into the in-coupling grating 120 according to a preset rule. At least one of the image source 180 and the optical lens assembly 190 is arranged at the connection of the wearing frame 160 to the wearing bracket 170.

[0174] The near-eye display device 2 comprises the wearing frame 160 and the wearing bracket 170. Specifically, the augmented reality display device 1 is AR glasses, and the wearing bracket 170 is also referred to as a glasses leg. The image source 180 is a device for generating an image, such as a Micro-LED display device.

[0175] When the augmented reality display device 1 is AR glasses, in order to make the waveguide substrate structure formed by the waveguide substrate 110, the in-coupling grating 120, the turning grating 130 and the out-coupling grating 140 as much as possible to conform to the shape of the glasses, the in-coupling grating 120 can be arranged at the connection of the wearing frame 160 to the wearing bracket 170. The layout form of side projection is adopted, and the image source 180 and the optical lens assembly 190 are placed at the connection of the wearing frame 160 to the wearing bracket 170. The in-coupling grating 120 is arranged on one side of the viewing window area 161. When the augmented reality display device 1 has two viewing window areas 161, the two in-coupling gratings 120 are respectively located on the opposite sides of the two viewing window areas 161. When the AR glasses are worn, the two in-coupling gratings 120 are distributed on the opposite sides of the human eyes.

[0176] Please refer to Figure 34 and Figure 35 , Figure 34 The schematic diagram of the augmented reality display device provided in another embodiment of the present application; Figure 35 is Figure 34A vector superposition diagram of the illustrated augmented reality display device. In the present embodiment, the augmented reality display device 1 comprises a waveguide substrate 110, a coupling-in grating 120 and a coupling-out grating 140. The coupling-in grating 120 is carried on the waveguide substrate 110 for coupling light into the waveguide substrate 110, and the grating vector of the coupling-in grating 120 is a first vector k1. The coupling-out grating 140 is carried on the waveguide substrate 110 for coupling light out of the waveguide substrate 110, and the coupling-out grating 140 has a second vector k2 and a third vector k3, wherein the first vector k1, the second vector k2 and the third vector k3 form a closed vector triangle, and when the augmented reality display device 1 is in use, the angle between the second vector k2 and the horizontal direction X is less than or equal to 45°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 45°.

[0177] The waveguide substrate 110 is described above and will not be described again here. The coupling-out grating 140 has a second vector k2 and a third vector k3, so the coupling-out grating 140 is a two-dimensional grating.

[0178] In Figure 34 and Figure 35 , the grating vector k1 of the coupling-in grating 120 is parallel to the horizontal direction X, and the coupling-out grating 140 is a two-dimensional grating, so there are two directions of coupling-out grating vectors, namely the second vector k2 and the third vector k3, wherein the angle between the second vector k2 and the horizontal direction X is denoted as θ1, and the angle between the third vector k3 and the horizontal direction X is denoted as θ2, and the vector superposition is as shown by the solid line in Figure 35 . When θ1 is less than or equal to 45° and θ2 is less than or equal to 45°, a better rainbow stripe suppression effect is obtained, and as the angles θ1 and θ2 decrease, the rainbow stripe suppression effect will be more and more obvious. When the direction of the first vector k1' of the coupling-in grating 120 (as shown by the dashed line in Figure 35 ) is not parallel to the horizontal direction X but forms an angle α, as long as θ1 is less than or equal to 45° and θ2 is less than or equal to 45°, a better rainbow stripe suppression effect can still be obtained, and the smaller the angle α, the more obvious the rainbow stripe suppression.

[0179] Therefore, when the augmented reality display device 1 is in use, the angle between the second vector k2 and the horizontal direction X is less than or equal to 45°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 45°, which can reduce or even eliminate the rainbow stripe effect.

[0180] In an embodiment, the angle between the second vector k2 and the horizontal direction X is less than or equal to 30°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 30°.

[0181] In an embodiment, the angle between the second vector k2 and the horizontal direction X is less than or equal to 30°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 30°. It is more difficult to appear rainbow stripes even in the morning or in the evening. Therefore, when the angle between the second vector k2 and the horizontal direction X is less than or equal to 30°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 30° in an embodiment, the -1 order transmitted light of the out-coupling grating 140 can be more effectively deviated from the eye movement range, and the rainbow stripe phenomenon can be more effectively alleviated.

[0182] It should be noted that in actual applications, the value of the angle between the second vector k2 and the horizontal direction X, and the value of the angle between the third vector k3 and the horizontal direction X are selected in consideration of the alleviation of the rainbow stripe phenomenon and the imaging factor of the augmented reality display device.

[0183] In the embodiment, the first vector k1, the second vector k2 and the third vector k3 form a closed vector triangle to ensure that the augmented reality display device 1 can form an image.

[0184] In an embodiment, the angle θ1 between the second vector k2 and the horizontal direction X is less than or equal to 45°, the angle θ2 between the third vector k3 and the horizontal direction X is less than or equal to 45°, and the angle θ1 between the second vector k2 and the horizontal direction X is equal to the angle θ2 between the third vector k3 and the horizontal direction X. When θ1 is equal to θ2, the out-coupling grating 140 is easier to prepare, the process difficulty of preparing the out-coupling grating 140 is smaller, and the effect of reducing rainbow stripes is better.

[0185] It can be understood that in other embodiments, the angle θ1 between the second vector k2 and the horizontal direction X is less than or equal to 45°, the angle θ2 between the third vector k3 and the horizontal direction X is less than or equal to 45°, and the angle θ1 between the second vector k2 and the horizontal direction X is not equal to the angle θ2 between the third vector k3 and the horizontal direction X. As long as the angle θ1 between the second vector k2 and the horizontal direction X is less than or equal to 45°, and the angle θ2 between the third vector k3 and the horizontal direction X is less than or equal to 45°, the rainbow stripes can be reduced.

[0186] The out-coupling grating 140 is a three-dimensional grating in a preset pattern in the XY plane and extending in the Z direction, wherein the preset pattern is any one of a circle, a T shape, and a diamond.

[0187] The coupling-in grating 120 and the coupling-out grating 140 are disposed on the same side of the waveguide substrate 110, or on opposite sides of the waveguide substrate 110. Please refer to the following: Figure 36 to Figure 39 ,exist Figure 36 In this configuration, the coupling-in grating 120 and the coupling-out grating 140 are disposed on the same side of the waveguide substrate 110, specifically, both are disposed on the outer surface 111 of the waveguide substrate 110. Figure 37 In this configuration, the coupling-in grating 120 and the coupling-out grating 140 are disposed on the same side of the waveguide substrate 110, specifically on the inner surface 112 of the waveguide substrate 110. Figure 38 In this configuration, the coupling grating 120 is disposed on the outer surface 111 of the waveguide substrate 110, and the coupling grating 140 is disposed on the inner surface 112 of the waveguide substrate 110. Figure 39 In the waveguide substrate 110, the coupling grating 120 is disposed on the inner surface 112 of the waveguide substrate 110, and the coupling grating 140 is disposed on the outer surface 111 of the waveguide substrate 110.

[0188] In one embodiment, the coupling grating 140 and the waveguide substrate 110 are an integral structure.

[0189] The coupling grating 140 can be formed on the substrate by imprinting technology, etc. That is, the imprinted part of the substrate constitutes the coupling grating 140, and the unimprinted part of the substrate forms the waveguide substrate 110. Therefore, the coupling grating 140 and the waveguide substrate 110 are an integral structure.

[0190] In another embodiment, the coupling grating 120 and the waveguide substrate 110 are also an integral structure. Specifically, the output grating 140 can be formed on a substrate by imprinting technology, that is, the imprinted portion of the substrate constitutes the coupling grating 120, and the unimprinted portion of the substrate forms the waveguide substrate 110. Therefore, the coupling grating 120 and the waveguide substrate 110 are an integral structure.

[0191] In another embodiment, the coupling grating 120, the coupling grating 140, and the waveguide substrate 110 are an integral structure. Specifically, the coupling grating 120 and the coupling grating 140 can be formed on a substrate using imprinting technology, etc. That is, the imprinted portion of the substrate constitutes the coupling grating 120 and the coupling grating 140, and the unimprinted portion of the substrate forms the waveguide substrate 110. Therefore, the coupling grating 120, the coupling grating 140, and the waveguide substrate 110 are an integral structure.

[0192] Please see Figure 40 , Figure 40A schematic diagram of an augmented reality display device according to another embodiment of the present application is shown. In this embodiment, the augmented reality display device 1 comprises a waveguide substrate 110, an in-coupling grating 120, and an out-coupling grating 140. In addition, the augmented reality display device 1 further comprises a polarizer 150. The waveguide substrate 110, the in-coupling grating 120, and the out-coupling grating 140 are as previously described and will not be repeated here. The light exiting the polarizer 150 enters the out-coupling grating 140, wherein the polarization direction of the polarizer 150 is parallel to the second vector k2, or parallel to the third vector k3, or between the second vector k2 and the third vector k3.

[0193] The polarization direction of the reflected light of the sunlight via reflection of glass or the like in the environment is usually along the Y-axis direction. By setting the polarization direction to be parallel to the second vector k2, or parallel to the third vector k3, or between the second vector k2 and the third vector k3, the part of the reflected light polarized along the Y-axis direction in the environment can be filtered out, further avoiding the generation of rainbow fringes.

[0194] The waveguide substrate 110 comprises an outer surface 111 and an inner surface 112 arranged opposite to each other. In this embodiment, the polarizer 150 and the out-coupling grating 140 are both arranged on the outer surface 111 of the waveguide substrate 110, and the polarizer 150 is arranged away from the waveguide substrate 110 compared to the out-coupling grating 140.

[0195] Further, in this embodiment, the augmented reality display device 1 further comprises a protective sheet 210, which can be made of, but is not limited to, glass, plastic, or the like. The protective sheet 210 is arranged on the surface of the polarizer 150 away from the out-coupling grating 140, for protecting the polarizer 150 from damage. It can be understood that, in another embodiment, the augmented reality display device 1 can not comprise the protective sheet 210.

[0196] Please refer to Figure 41 , Figure 41 A schematic diagram of an augmented reality display device according to another embodiment of the present application is shown. In this embodiment, the augmented reality display device 1 comprises a waveguide substrate 110, an in-coupling grating 120, and an out-coupling grating 140. In addition, the augmented reality display device 1 further comprises a polarizer 150. The waveguide substrate 110, the in-coupling grating 120, and the out-coupling grating 140 are as previously described and will not be repeated here. The light exiting the polarizer 150 enters the out-coupling grating 140, wherein the polarization direction of the polarizer 150 is parallel to the second vector k2, or parallel to the third vector k3, or between the second vector k2 and the third vector k3.

[0197] The waveguide substrate 110 comprises an outer surface 111 and an inner surface 112 disposed oppositely, the polarizer 150 is disposed on the outer surface 111 of the waveguide substrate 110, and the out-coupling grating 140 is disposed on the inner surface 112 of the waveguide substrate 110.

[0198] Further, in the present embodiment, the augmented reality display device 1 further comprises a protective sheet 210, which can be made of, but not limited to, glass, plastic, etc. The protective sheet 210 is disposed on the surface of the polarizer 150 away from the waveguide substrate 110, for protecting the polarizer 150 from damage. It can be understood that in another embodiment, the augmented reality display device 1 can not comprise the protective sheet 210.

[0199] In an embodiment, the polarizer 150 is a coated polarizer. In other words, the polarizer 150 is a polarizer formed by a coating process. When the polarizer 150 and the out-coupling grating 140 are both disposed on the outer surface 111 of the waveguide substrate 110, and the polarizer 150 is disposed away from the waveguide substrate 110 compared to the out-coupling grating 140, the polarizer 150 is a film coated on the outer surface 111 of the out-coupling grating 140. When the polarizer 150 is disposed on the outer surface 111 of the waveguide substrate 110, and the out-coupling grating 140 is disposed on the inner surface 112 of the waveguide substrate 110, the polarizer 150 is a film coated on the outer surface 111 of the waveguide substrate 110. In another embodiment, the polarizer 150 is a single-piece polarizer, which is bonded to the out-coupling grating 140 or the waveguide substrate 110 by an adhesive or the like.

[0200] The polarizer 150 is a coated polarizer, which can make the polarizer 150 thinner and easier to manufacture.

[0201] Please refer to Figure 42 , Figure 42 A schematic diagram of a near-eye display device according to yet another embodiment of the present application is provided. The near-eye display device 2 comprises the augmented reality display device 1 according to any of the preceding embodiments.

[0202] In an embodiment, the near-eye display device 2 further comprises a wearing frame 160. The wearing frame 160 has two viewing window regions 161 disposed at intervals, and at least one of the two viewing window regions 161 is provided with the out-coupling grating 140.

[0203] When one of the two window regions 161 is provided with the out-coupling grating 140, the one window region 161 can make the human eye see the virtual image, while the in-coupling grating 120 region itself can be transparent to ambient light, so that one window region 161 can achieve the effect of augmented reality. When both of the two window regions 161 are provided with the out-coupling grating 140, the two window regions 161 can achieve the effect of augmented reality. In the schematic diagram of the embodiment, both of the two window regions 161 are provided with the out-coupling grating 140 as an example.

[0204] Please refer to Figure 43 , Figure 43 A schematic diagram of a near-eye display device according to another embodiment of the present application is provided. The near-eye display device 2 comprises the augmented reality display device 1 according to any of the preceding embodiments.

[0205] In an embodiment, the near-eye display device 2 further comprises a wearing frame 160, and further comprises a wearing support 170, an image source 180, and an optical lens assembly 190. The wearing support 170 is connected to the wearing frame 160. The image source 180 is arranged on one side of the waveguide substrate 110, and is configured to generate light according to an image to be displayed. The optical lens assembly 190 is arranged between the image source 180 and the in-coupling grating 120, and is configured to project the light into the in-coupling grating 120 according to a preset rule. At least one of the image source 180 and the optical lens assembly 190 is arranged at a connection position of the wearing frame 160 connected to the wearing support 170.

[0206] The near-eye display device 2 further comprises a wearing frame 160 and a wearing support 170, and specifically, is an AR glasses. The micro image source is an image generation device, such as a Micro-LED display device.

[0207] When the augmented reality display device 1 is an AR glasses, in order to make the waveguide substrate structure formed by the waveguide substrate 110, the in-coupling grating 120, and the out-coupling grating 140 as much as possible to conform to the shape of the glasses, the in-coupling grating 120 can be arranged at the connection position of the wearing frame 160 connected to the wearing support 170. A side projection layout form is adopted, and the image source 180 and the optical lens assembly 190 are placed at the connection position of the wearing frame 160 connected to the wearing support 170, and the in-coupling grating 120 is arranged on one side of the window region 161. When the near-eye display device 1 has two window regions 161, the two in-coupling gratings 120 are respectively located on opposite sides of the two window regions 161. When the AR glasses are worn, the two in-coupling gratings 120 are distributed on opposite sides of the human eye.

[0208] In an embodiment, the augmented reality display device 1 can be arranged on the windshield of a vehicle, for example, the augmented reality display device 1 can be arranged on the side of the windshield of the vehicle close to the human eye. The augmented reality display device 1 can be directly attached to the windshield, or can not be directly attached to the windshield and arranged spaced apart from the windshield.

[0209] Please refer to Figure 44 , Figure 44 The schematic diagram of the near-eye display device provided in another embodiment of the present application is shown in FIG. 2. The near-eye display device 2 further comprises a camera 230, an environmental sensor 240, a processor 250, and a battery 260. The image source 180, the camera 230, and the environmental sensor 240 are electrically connected to the processor 250 and work under the control of the processor 250. The camera 230 is used to collect video data, and the environmental sensor 240 is used to detect the surrounding environment. The battery 260 is used to supply power to the image source 180, the camera 230, and the environmental sensor 240.

[0210] The principles and embodiments of the present application are described herein by using specific examples, and the above descriptions of the examples are only used to help understand the core idea of the present application; meanwhile, for those skilled in the art, according to the idea of the present application, the specific embodiments and application scope can be changed, and the above descriptions of the present application should not be understood as limiting the present application.

Claims

1. An augmented reality display device, characterized by comprising: The augmented reality display device comprises: a waveguide substrate; an in-coupling grating carried on the waveguide substrate for in-coupling light into the waveguide substrate, and a grating vector of the in-coupling grating being a first vector K1; a turning grating carried on the waveguide substrate for expanding pupils of the light in-coupled into the waveguide substrate by the in-coupling grating, wherein a grating vector of the turning grating is a second vector K2; and an out-coupling grating carried on the waveguide substrate for receiving the light expanded by the turning grating and out-coupling the light from the waveguide substrate, and a grating vector of the out-coupling grating being a third vector K3, wherein the first vector K1, the second vector K2 and the third vector K3 form a closed vector triangle to ensure that the augmented reality display device can form an image, and when the augmented reality display device is used, an angle A between a direction of the third vector K3 and a horizontal direction X ranges from -45° to 45°, so that the out-coupling grating deviates -1 order transmission light of external environment light from an eye movement range.

2. The augmented reality display device of claim 1, wherein, The angle A between the direction of the third vector K3 and the horizontal direction X ranges from -30° to 30°.

3. The augmented reality display device of claim 1, wherein, The out-coupling grating comprises a plurality of out-coupling units arranged at intervals and periodically, and a period of the out-coupling grating is less than or equal to 450 nm.

4. The augmented reality display device of claim 1, wherein, An area of the out-coupling grating is a rectangle, wherein a side length of the rectangle satisfies: d = m + l*tan(FOV / 2)*2 wherein d is the side length of the rectangle, m is a user eye movement range, l is a distance from a user eye to a waveguide sheet, and FOV is a field of view angle of the augmented reality display system.

5. The augmented reality display device of claim 1, wherein, The period of the out-coupling grating is the same as that of the in-coupling grating.

6. The augmented reality display device of claim 1, wherein, The in-coupling grating and the out-coupling grating are arranged on the same side of the waveguide substrate or on opposite sides of the waveguide substrate.

7. The augmented reality display device of claim 6, wherein, The out-coupling grating and the waveguide substrate are an integral structure.

8. The augmented reality display device of claim 1, wherein, The out-coupling grating is any one of a blazed grating, an inclined grating, a binary grating and a photonic crystal.

9. The augmented reality display device of claim 1, wherein, The augmented reality display device further comprises: a polarizer, wherein light emitted by the polarizer enters the out-coupling grating, and a polarization direction of the polarizer is the horizontal direction X.

10. The augmented reality display device of claim 9, wherein, The waveguide substrate comprises an outer surface and an inner surface arranged oppositely, the polarizer and the out-coupling grating are arranged on the outer surface of the waveguide substrate, and the polarizer is arranged away from the waveguide substrate compared with the out-coupling grating.

11. The augmented reality display device of claim 9, wherein, The waveguide substrate comprises an outer surface and an inner surface arranged oppositely, the polarizer is arranged on the outer surface of the waveguide substrate, and the out-coupling grating is arranged on the inner surface of the waveguide substrate.

12. The augmented reality display device of claim 10 or 11, wherein, The polarizer is a coated polarizer.

13. An augmented reality display device, characterized by The augmented reality display device comprises: a waveguide substrate; an in-coupling grating carried on the waveguide substrate for in-coupling light into the waveguide substrate, and a grating vector of the in-coupling grating being a first vector k1; a coupling-out grating carried on the waveguide substrate for coupling light rays in the waveguide substrate out of the waveguide substrate, the coupling-out grating having a second vector k2 and a third vector k3, wherein the first vector k1, the second vector k2 and the third vector k3 form a closed vector triangle to ensure that the augmented reality display device can form an image, and when the augmented reality display device is used, an angle between the second vector k2 and a horizontal direction X is less than or equal to 45°, and an angle between the third vector k3 and the horizontal direction X is less than or equal to 45°, so that the coupling-out grating deviates -1 order transmission light rays of external ambient light rays from an eye movement range.

14. The augmented reality display device of claim 13, wherein, The angle between the second vector k2 and the horizontal direction X is less than or equal to 30°, and the angle between the third vector k3 and the horizontal direction X is less than or equal to 30°.

15. The augmented reality display device of claim 13, wherein, The angle between the second vector k2 and the horizontal direction X is equal to the angle between the third vector k3 and the horizontal direction X.

16. The augmented reality display device of claim 13, wherein, The coupling-in grating and the coupling-out grating are arranged on the same side of the waveguide substrate, or on opposite sides of the waveguide substrate.

17. The augmented reality display device of claim 16, wherein, The coupling-out grating and the waveguide substrate are an integral structure.

18. The augmented reality display device of claim 13, wherein, The augmented reality display device further comprises: a polarizer, light rays exiting from the polarizer enter the coupling-out grating, wherein a polarization direction of the polarizer is parallel to the second vector k2, or parallel to the third vector k3, or between the second vector k2 and the third vector k3.

19. The augmented reality display device of claim 13, wherein, The coupling-out grating is a three-dimensional grating in a preset pattern in the XY plane and extending in the Z direction, wherein the preset pattern is any one of a circle, a T shape, and a diamond.

20. A near-eye display device comprising the augmented reality display device according to any one of claims 1-19.

21. The near-eye display device of claim 20, wherein, The near-eye display device comprises: a wearing frame having two viewing window regions arranged at intervals, at least one of the two viewing window regions being provided with the coupling-out grating.

22. The near-eye display device of claim 21, wherein, The near-eye display device further comprises: a wearing frame connected to the wearing frame; an image source arranged on one side of the waveguide substrate for generating light rays according to an image to be displayed; and an optical lens assembly arranged between the image source and the coupling-in grating for projecting the light rays into the coupling-in grating according to a preset rule, at least one of the image source and the optical lens assembly being arranged at a connection of the wearing frame connected to the wearing frame.

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