Augmented reality head-up display device, vehicle, and method of manufacturing optical waveguide

Abstract

The application relates to an augmented reality head-up display device, which comprises an image unit, a light waveguide unit and a reflection unit, the image unit is used for generating image light and guiding the image light to be incident on the surface of the light waveguide unit, the light waveguide unit conducts the image light and emits the image light towards the reflection unit, the reflection unit reflects the image light to the human eye and generates a virtual image, the light waveguide unit comprises at least one light waveguide, the light waveguide comprises at least two light waveguide parts which are optically connected, the planes where the surfaces of the two adjacent light waveguide parts are located have an included angle, so that compared with a plane AR-HUD, the augmented reality head-up display device has a smaller surface area, a more reasonable space distribution and a larger front mounting tolerance, the augmented reality head-up display device has the performances of a large field of view, a small volume, a long virtual image distance and a simple structure, is suitable for most windshields, and has high mass production universality.

Description

TECHNICAL FIELD

[0001] The application relates to a kind of enhanced reality head-up display device, vehicle and preparation method of optical waveguide, belong to display equipment technical field. BACKGROUND

[0002] Head-up display ((head up display, HUD) functions as a role of car information "projector". The technology can project car related information in front of the driver's line of sight, so as to reduce the frequency of looking down to check the instrument or central control screen during driving. The traditional HUD is an optoelectromechanical coupling component, mainly composed of a master control PCB board, a light source, a display medium, an optical lens group, a direct current motor and the like. The information is reflected to the transparent medium (display screen or windshield) by the display light source through multiple mirror structure reflections, so that the human eye sees a virtual image floating in front of the eyes. The use of HUD greatly improves driving comfort and safety, and it is expected that the global HUD installation volume will reach 15 million in 2025.

[0003] According to the product form, the current mainstream HUD is mainly divided into combined type (C-HUD) and windshield type (W-HUD). Technically, the optical structure of C-HUD is simple, and the design is relatively easy, but the display size and projection distance are limited, and it may cause secondary damage to the driver in vehicle collision; the display effect of W-HUD is more integrated, but its optical structure is complex, and the design and arrangement are difficult, and it occupies a large volume, and its optical principle needs to cooperate with a complex windshield, which undoubtedly increases the difficulty of preparation and mass production.

[0004] In recent years, the enhanced reality head-up display (AR-HUD) based on optical waveguide has emerged, which superimposes digital images on the real environment outside the vehicle, so that the driver obtains the visual effect of augmented reality, which can be used for AR navigation, adaptive cruise, lane departure warning and the like.

[0005] Compared with the current mainstream C-HUD and W-HUD, AR-HUD has the characteristics of small volume, long projection distance, large field of view angle and high universality. In the prior art, the optical waveguide in AR-HUD is a planar optical waveguide. In order to expand the eye movement range, the surface area of the optical waveguide needs to be increased, which greatly brings difficulties to the front installation of AR-HUD. SUMMARY

[0006] The purpose of the present application is to provide an enhanced reality head-up display device with smaller surface area, more reasonable spatial distribution and larger front installation tolerance.

[0007] To achieve the above object, the present application provides the following technical scheme: An augmented reality head-up display device, comprising an image unit, a light waveguide unit and a reflection unit, the image unit is used to generate image light and guide the image light to be incident on the surface of the light waveguide unit, the light waveguide unit conducts the image light and emits it towards the reflection unit, the reflection unit reflects the image light to the human eye and generates a virtual image, the light waveguide unit comprises at least one light waveguide, the light waveguide comprises at least two light-connected light waveguide parts, the planes where the surfaces of the two adjacent light waveguide parts are located have an included angle.

[0008] Further, the planes where the surfaces of the two adjacent light waveguide parts are perpendicular to each other.

[0009] Further, the light waveguide comprises a first light waveguide part arranged close to the image unit and a second light waveguide part arranged close to the reflection unit, the light waveguide unit further comprises a first light shielding layer arranged on one side of the first light waveguide part and a second light shielding layer arranged on one side of the second light waveguide part, the first light shielding layer is used to absorb the light transmitted from the first light waveguide part, and the second light shielding layer is used to absorb the light transmitted and / or reflected from the second light waveguide part and the sunlight transmitted from the outside.

[0010] Further, the first light shielding layer and the second light shielding layer have a gap between them and the light waveguide.

[0011] Further, the image unit and the first light shielding layer are arranged on the two sides of the first light waveguide part respectively; the reflection unit and the second light shielding layer are arranged on the two sides of the second light waveguide part respectively.

[0012] Further, the absorption rate of the first light shielding layer and the second light shielding layer to the visible light waveband is greater than 60%.

[0013] Further, the surface of the light waveguide is provided with a coupling-in area and a coupling-out area, the coupling-in area is configured to couple the incident image light into the light waveguide and conduct it along the light waveguide to the coupling-out area, the coupling-out area is configured to emit the image light in the waveguide, the coupling-in area is arranged on the first light waveguide part, and the coupling-out area is arranged on the second light waveguide part.

[0014] Further, the first light shielding layer covers the projection area of the coupling-in area on the surface of the first light waveguide part.

[0015] Further, the second light shielding layer covers the projection area of the coupling-out area on the surface of the second light waveguide part.

[0016] The application also provides a preparation method for preparing the optical waveguide as described above, the method comprising:

[0017] S1: preparing a master with nanostructures;

[0018] S2: transferring the nanostructures on the master to a submaster through a nanoimprint process;

[0019] S3: transferring the nanostructures of the submaster to at least two optical waveguide parts through a nanoimprint process;

[0020] S4: adding a refractive index matching curing agent in the optical waveguide parts to form optical waveguide part adhesion through curing to obtain an optical waveguide.

[0021] The application also provides a vehicle comprising the augmented reality head-up display device as described above.

[0022] The application has the beneficial effect that the optical waveguide of the augmented reality head-up display device comprises at least two optical waveguide parts optically connected, and the planes in which the surfaces of the two adjacent optical waveguide parts are located have an included angle, so that compared with the planar AR-HUD, it has a smaller surface area, a more reasonable spatial distribution and a larger front mounting tolerance, the augmented reality head-up display device has the performance of a large field of view, a small volume, a long virtual image distance, and a simple structure, and is suitable for most windshields, and has high mass production universality.

[0023] The above description is only a summary of the technical solutions of the application, in order to more clearly understand the technical means of the application, and to implement the content of the description, the following will be described in detail with the preferred embodiments of the application and in conjunction with the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic diagram of the optical path of the augmented reality head-up display device with a planar optical waveguide in the prior art;

[0025] Figure 2 is a schematic diagram of the optical path of the planar optical waveguide shown in Figure 1

[0026] Figure 3 is a schematic diagram of the structure of the partial augmented reality head-up display device shown in Figure 1

[0027] Figure 4 is a spatial schematic diagram of the partial augmented reality head-up display device shown in Figure 1

[0028] Figure 5 is a schematic diagram of the optical path of the augmented reality head-up display device shown in an embodiment of the application;​​​

[0029] Figure 6 FIG. 1 is a spatial diagram of a partial augmented reality head-up display device according to an embodiment of the present disclosure; Figure 5

[0030] Figure 7 FIG. 2 is a spatial diagram of a partial augmented reality head-up display device according to an embodiment of the present disclosure; Figure 1 Figure 5

[0031] Figure 8 Figure 1 Figure 5

[0032] Figure 9 FIG. 5 is a partial optical path diagram of an augmented reality head-up display device without a first light blocking layer according to an embodiment of the present disclosure; Figure 5

[0033] Figure 10 FIG. 6 is a partial optical path diagram of an augmented reality head-up display device with a first light blocking layer according to an embodiment of the present disclosure; Figure 5

[0034] Figure 11 FIG. 7 is a partial optical path diagram of an augmented reality head-up display device without a second light blocking layer according to an embodiment of the present disclosure; Figure 5

[0035] Figure 12 FIG. 8 is a partial optical path diagram of an augmented reality head-up display device with a second light blocking layer according to an embodiment of the present disclosure; Figure 5

[0036] Figure 13 FIG. 9 is another structural optical path diagram of a partial augmented reality head-up display device according to an embodiment of the present disclosure; Figure 5

[0037] Figure 14 FIG. 10 is a third structural optical path diagram of a partial augmented reality head-up display device according to an embodiment of the present disclosure; Figure 5

[0038] Figure 15 FIG. 11 is a fourth structural optical path diagram of a partial augmented reality head-up display device according to an embodiment of the present disclosure; Figure 5

[0039] Figure 16 FIG. 12 is a structural diagram of a junction according to an embodiment of the present disclosure; Figure 5

[0040] Figure 17 FIG. 13 is another structural diagram of a junction according to an embodiment of the present disclosure; Figure 5

[0041] Figure 18 ​​​​​​​​​​​​​​​Another schematic view of the image unit and the optical waveguide shown in Figure 5 Another schematic view of the image unit and the optical waveguide shown in

[0042] Figure 19 Another schematic view of the image unit and the optical waveguide shown in Figure 5 Another schematic view of the image unit and the optical waveguide shown in

[0043] Figure 20 Another schematic view of the image unit and the optical waveguide shown in Figure 5 Another schematic view of the image unit and the optical waveguide shown in

[0044] Figure 21 Another schematic view of the image unit and the optical waveguide shown in Figure 20 Another schematic view of the image unit and the optical waveguide shown in

[0045] Figure 22 Another schematic view of the image unit and the optical waveguide shown in Figure 5 Another schematic view of the image unit and the optical waveguide shown in

[0046] Figure 23 Another schematic view of the image unit and the optical waveguide shown in DETAILED DESCRIPTION

[0047] The technical solutions of the present application will be described clearly and completely below with reference to the drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0048] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0049] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0050] Please refer to Figure 5The augmented reality head-up display device shown in an embodiment of the present application includes an image unit 1, a light waveguide unit 2, and a reflection unit 3. The image unit 1 is used to generate image light and guide the image light to be incident on the surface of the light waveguide unit 2. The light waveguide unit 2 conducts the image light while increasing the exit pupil expansion and emits the image light toward the reflection unit 3. The image light emitted by the light waveguide unit 2 is incident on the reflection unit 3, and the reflection unit 3 reflects the image light incident thereon to the human eye and generates a virtual image.

[0051] The head-up display principle of the augmented reality head-up display device is that the image unit 1 emits image light of a certain field of view, the image light is incident on the light waveguide unit 2, is emitted after the exit pupil expansion of the light waveguide unit 2, and the emitted image light is reflected to the human eye at a certain reflection angle by the reflection unit 3, so that the human eye can see a virtual image at a certain projection distance through the reflection unit 3.

[0052] The light waveguide unit 2 includes at least one light waveguide 21, which can be one light waveguide 21, two light waveguides 21, or three light waveguides 21, etc. In this embodiment, the light waveguide unit 2 includes three light waveguides 21 stacked together, and the number of layers of the light waveguide 21 is not specifically limited here and can be set according to actual needs.

[0053] Please refer to Figure 7 and Figure 8 The light waveguide 21 is provided with a coupling-in region 22 and a coupling-out region 23 on the surface. The coupling-in region 22 is configured to couple the incident image light into the light waveguide 21 and conduct the image light in the light waveguide 21 to the coupling-out region 23. The coupling-out region 23 is configured to emit the image light in the waveguide. The image light passes through the coupling-in region 22, undergoes diffraction and total reflection inside the light waveguide 21, the diffracted and totally reflected image light is conducted multiple times inside the light waveguide 21, the image light fills the entire coupling-out region 23 and is emitted from the coupling-out region 23, thereby realizing the exit pupil expansion. The light waveguide 21 can continuously conduct the coupled-in light in a specific direction under the condition of satisfying total reflection. The transmittance of the light waveguide 21 is greater than 80%. The light waveguide 21 can be glass, resin, or a material with a transmittance greater than 80% under visible light, which is not listed one by one here. The thickness of the light waveguide 21 is less than 2 mm, and the specific thickness of the light waveguide 21 is not specifically limited here and can be set according to actual needs.

[0054] The coupling-in region 22 and the coupling-out region 23 are structural units with diffraction characteristics, and essentially are nanostructures with refractive index gradients and capable of realizing light diffraction transmission. Specifically, the coupling-in region 22 and the coupling-out region 23 are both periodic grating structures, such as nanoscale relief gratings or volume holographic gratings. The periodic grating structures can be directly fabricated on the optical waveguide 21, or can be pre-fabricated on a film, and then the film carrying the grating structure is combined with the optical waveguide 21. The bottom of the grating structure forming the coupling-in region 22 and the coupling-out region 23 can be located on the surface of the optical waveguide 21 or inside the optical waveguide 21.

[0055] The coupling-in region 22 and the coupling-out region 23 can both be rectangular, and the coupling-in region 22 can also be circular or other shapes, as needed. The grating structure can be prepared by holographic interference technology, photolithography technology or nanoimprint technology, and can be freely selected according to actual needs.

[0056] The coupling-in region 22 is preferably an inclined relief grating, and the image light is incident at the coupling-in region 22 position and is coupled into the optical waveguide 21 through the diffraction process. The inclined diffraction grating is selective to wavelength, avoids dispersion, and has high diffraction efficiency for a certain wavelength band. The grating structure of the coupling-out region 23 has the same period and orientation as the grating of the coupling-in region 22, and can be a positive grating or an inclined grating.

[0057] By designing the period, depth, duty cycle and inclination angle of the grating structure, light of a specific wavelength or wavelength band is efficiently selected, realizing the wavelength selective function. For example, the green image light is coupled and then bent and transmitted in the waveguide, and the blue and red image light is not affected, realizing single-channel light diffraction. Or the blue and red wavelength band light is efficiently selected, realizing double-channel light diffraction. The single-channel diffraction optical waveguide 21 only transmits image light of a certain color, and the image light of other colors passes through the optical waveguide 21, realizing that the light does not interfere with each other.

[0058] In addition, the surface of the optical waveguide 21 can also be provided with a turning region (not shown), which is used to change the propagation direction of the image light in the optical waveguide 21. When the image light is incident on the coupling-in region 22, the image light is totally reflected to the turning region in the optical waveguide 21, the turning region changes the propagation direction of the image light, and the image light after changing the direction is totally reflected to the coupling-out region 23, which can effectively expand the pupil of the output image, thereby expanding the viewing angle range and better meeting the user's needs.

[0059] Please refer to Figure 1 , in the prior art planar AR-HUD scheme, the image unit 1 emits image light of a certain field of view angle, which is expanded by the exit pupil of the optical waveguide unit 2 and then reflected by the reflection unit 3 to the human eye to form a virtual image, but the optical waveguide 21 is a planar optical waveguide 21.

[0060] Please see Figure 2 The coupling region 22 and coupling region 23 of the planar optical waveguide 21 are arranged along the same axis on both sides of the same surface or on both sides of different surfaces of the optical waveguide 21. The coupling region 22 and coupling region 23 of the planar optical waveguide 21 are located on the same surface of the optical waveguide 21 and are spaced apart. When light passes through the coupling region 22, diffraction and total internal reflection occur inside the waveguide. The diffracted and totally reflected light is propagated multiple times inside the waveguide, and the light fills the entire coupling region 23, thereby achieving exit pupil expansion.

[0061] Please see Figure 3 and Figure 4 The optical waveguide 21 requires the image light emitted from the image unit 1 to enter the coupling region 22, and then be guided through the waveguide pupil expansion before entering the coupling region 23. Since the coupling region 22 and the coupling region 23 are horizontally aligned, only the light emitted from the coupling region 23 is transmitted to the reflection unit 3; the coupling region 22 does not participate in the emission of light to the reflection unit 3. Therefore, the eye movement range corresponds to the range of the coupling region 23 of the optical waveguide 21. To obtain a larger eye movement range, the surface area of ​​the optical waveguide 21 needs to be increased. Simultaneously, the optical waveguide 21 requires a certain amount of transmission space for the coupling region 22 and the coupling region 23. This space, combined with the increased surface area, will occupy a significant amount of space, affecting the feasibility of front-mounting a HUD.

[0062] Please see Figure 5 , Figure 7 and Figure 8 To reduce the space occupied by the optical waveguide unit 2 and improve the feasibility of HUD pre-installation, in this embodiment, the optical waveguide 21 includes at least two optically connected optical waveguide sections. The planes containing the surfaces of two adjacent optical waveguide sections have an included angle, which is greater than 0° and less than 180°, meaning that the planes containing the surfaces of two adjacent optical waveguide sections are not parallel. In this embodiment, the planes containing the surfaces of two adjacent optical waveguide sections are perpendicular to each other. It should be noted that adjacent optical waveguide sections can be bonded and fixed together by a curing agent or adhesive, or adjacent optical waveguide sections can be integrally formed, and when light enters from one optical waveguide section to an adjacent optical waveguide section, all light can pass through, that is, the optical properties of the adhesive layer provided between adjacent optical waveguide sections are consistent with those of the optical waveguide sections.

[0063] The optical waveguide 21 includes a first optical waveguide portion 25 disposed near the image unit 1 and a second optical waveguide portion 26 disposed near the reflection unit 3, and the planes on which the surfaces of the first optical waveguide portion 25 and the second optical waveguide portion 26 lie are perpendicular to each other. Other optical waveguide portions may also be connected between the first optical waveguide portion 25 and the second optical waveguide portion 26. The following describes the process in detail using two optical waveguide portions as an example.

[0064] In this embodiment, the coupling-in region 22 is arranged on the first light waveguide section 25, and the coupling-out region 23 is arranged on the second light waveguide section 26. Specifically, the coupling-in region 22 and the image unit 1 are arranged on the same side of the first light waveguide section 25, and the coupling-out region 23 and the reflecting unit 3 are arranged on the same side of the second light waveguide section 26. The principle of the light waveguide 21 is as follows: the image light emitted by the image unit 1 is incident on the coupling-in region 22 of the first light waveguide section 25, is diffracted by the coupling-in region 22, and is totally reflected and conducted in the first light waveguide section 25, is transmitted to the coupling-out region 23 of the second light waveguide section 26, is coupled out of the coupling-out region 23 to the reflecting unit 3, and is reflected by the reflecting unit 3 to the human eye.

[0065] Referring to Figure 7 The solid line part is the light conducting diagram of the light waveguide 21 in this embodiment, and the dashed line is the light conducting diagram of the planar light waveguide 21. In the light waveguide 21 of this embodiment, the image light represented by the solid line part emitted by the image unit 1 is diffracted by the coupling-in region 22, the diffracted light is totally reflected and conducted in the light waveguide 21, when it is conducted to the joint of the first light waveguide section 25 and the second light waveguide section 26, the light can be directly incident on the second light waveguide section 26 from the first light waveguide section 25 at a total reflection angle, so as to continue to be totally reflected and conducted in the second light waveguide section 26 to the coupling-out region 23, and is emitted to the reflecting unit 3 through the coupling-out region 23.

[0066] In the planar light waveguide 21, assuming that the coupling-in region 22, the coupling-out region 23 and the image unit 1 are the same, at this time the image light represented by the dashed line part emitted by the image unit 1 is diffracted by the coupling-in region 22, the diffraction angle is the same as that of the light represented by the solid line, the diffracted light is totally reflected and continues to be conducted to the coupling-out region 23 through the planar light waveguide 21, and is emitted to the reflecting unit 3 through the coupling-out region 23.

[0067] It can be seen that the angle of the light represented by the solid line and the light represented by the dashed line is consistent when they are incident on the coupling-out region 23, that is, the light waveguide 21 shown in this embodiment does not have an essential change in the light path compared with the planar light waveguide 21, and meanwhile, the light conducting and bending in the light waveguide 21 can be realized.

[0068] Referring to Figure 8 , and Figure 7Similarly, the solid line represents the light transmission in the optical waveguide 21 of this embodiment, and the dashed line represents the light transmission in the planar optical waveguide 21. In the optical waveguide 21 of this embodiment, the image light emitted by the image unit 1, as shown by the solid line, is diffracted through the coupling region 22. The diffracted light is totally internally reflected within the optical waveguide 21. When it reaches the connection between the first optical waveguide 25 and the second optical waveguide 26, the light enters the side of the second optical waveguide 26 from the first optical waveguide 25 at a total internal reflection angle. Due to the total internal reflection within the optical waveguide 21, the light continues to be reflected by total internal reflection to the upper surface of the second optical waveguide 26. After total internal reflection from the upper surface, it is then transmitted within the second optical waveguide 26, and continues to be totally internally reflected within the second optical waveguide 26 to the coupling region 23, from which it exits to the reflecting unit 3.

[0069] In the planar optical waveguide 21, assuming that it has the same coupling region 22, coupling region 23 and image unit 1, the image light emitted by the dashed part of the image unit 1 is diffracted through the coupling region 22. The diffraction angle is the same as that of the light ray shown by the solid line. The diffracted light continues to be propagated to the coupling region 23 through total internal reflection of the planar optical waveguide 21, and then exits to the reflection unit 3 through the coupling region 23.

[0070] Light transmission in a planar waveguide and Figure 7 The same is shown in the figure, and will not be repeated here. It can also be seen that the angles of the light rays shown by the solid line and the light rays shown by the dashed line when incident on the coupling region 23 are the same. That is to say, compared with the planar light waveguide 21, the optical waveguide 21 shown in this embodiment does not have an essential change in the direction of the light rays, and can realize the transmission and bending of light rays in the optical waveguide 21.

[0071] Please see Figure 6 To increase the eye movement range, it is only necessary to increase the range of the coupling region 23 located in the second optical waveguide 26. The increased range of the coupling region 22 does not require increasing the size of the surface where the second optical waveguide 26 is located. Therefore, it does not increase the space requirement much and greatly reduces the requirement for the front surface area of ​​the HUD.

[0072] Please see Figure 5 The optical waveguide unit 2 further includes a first light-shielding layer 27 disposed on one side of the first optical waveguide portion 25 and a second light-shielding layer 28 disposed on one side of the second optical waveguide portion 26. The first light-shielding layer 27 is used to absorb light transmitted from the first optical waveguide portion 25, and the second light-shielding layer 28 is used to absorb light transmitted and / or reflected from the second optical waveguide portion 26, as well as sunlight transmitted from the outside. In this embodiment, the image unit 1 and the first light-shielding layer 27 are disposed opposite to each other on both sides of the first optical waveguide portion 25; the reflection unit 2 and the second light-shielding layer 28 are disposed opposite to each other on both sides of the second optical waveguide portion 26.

[0073] The first light shielding layer 27 and the second light shielding layer 28 have a gap between the light waveguide 21, so as to absorb the light transmitted or reflected from the light waveguide 21, and avoid absorbing the light inside the light waveguide 21. The specific gap is not limited here, and can be set according to actual needs. The first light shielding layer 27 and the second light shielding layer 28 have an absorption rate of greater than 60% for the visible light band, that is, the first light shielding layer 27 and the second light shielding layer 28 can be made of a structure or a material with an absorption rate of greater than 60% for the visible light band. The specific materials and structures are not listed one by one here, and can be selected according to actual needs.

[0074] Please refer to Figure 9 and Figure 10 If the light waveguide unit 2 is not provided with the first light shielding layer 27, the image light conducted in the light waveguide 21 will still have part of the image light transmitted out of the light waveguide 21 even after passing through multiple light waveguides 21. In particular, whether the image light is perpendicular to the incident or oblique to the coupling-in area, only part of the light will be diffracted and then conducted in the light waveguide 21, and the 0th-order diffracted light will be transmitted out of the light waveguide 21. This part of the image light will be reflected or diffusely reflected by any surface with reflection characteristics. The light after reflection or diffuse reflection will be incident into the light waveguide 21 again, introducing stray light and affecting the imaging quality. Please refer to Figure 23 In the visible light band, when the image light enters the coupling-in area 22, part of the light will be transmitted out. Among them, as the wavelength of the image light increases, the reflection efficiency of the light waveguide 21 to the image light gradually increases, and the transmission efficiency gradually decreases, and the absorption efficiency is always close to 0. However, if the light waveguide unit 2 is provided with the first light shielding layer 27, the first light shielding layer 27 will absorb the image light transmitted out of the light waveguide 21, avoiding the image light after reflection or diffuse reflection from being incident into the light waveguide 21 again, thereby weakening the interference and improving the imaging quality.

[0075] The first light shielding layer 27 covers the projection area of the coupling-in area on the surface of the first light waveguide part 25, thereby maximizing the absorption of the light transmitted out of the surface of the first light waveguide part 25. That is, the first light shielding layer 27 covers the minimum range of the projection area of the coupling-in area on the surface of the first light waveguide part 25.

[0076] Please refer to Figure 11 and Figure 12, if the second light shielding layer 28 is not provided in the optical waveguide unit 2, the image light rays conducted in the optical waveguide 21 will be transmitted out of the light waveguide 21 through the side opposite to the reflecting unit 3 after passing through the multiple optical waveguides 21, and the sunlight from the outside will also be transmitted out of the light waveguide 21 through the side opposite to the reflecting unit 3 after passing through the reflecting unit 3, that is, the sunlight will also be backflowed and conducted reversely in the optical waveguide 21, which will cause the key device to be damaged due to the temperature rise. Meanwhile, when the image light rays are incident on the optical waveguide 21, part of the light rays will be reflected on the surface of the optical waveguide 21, and these light rays will be reflected or diffused by any surface with reflecting properties, and the light rays reflected or diffused will be incident on the optical waveguide 21 again, which will introduce stray light and affect the imaging quality. If the second light shielding layer 28 is provided in the optical waveguide unit 2, the second light shielding layer 28 will absorb the three parts of light rays, so that the light rays will not be incident on the optical waveguide 21 again or conducted reversely after being reflected or diffused, thereby weakening the influence and improving the imaging quality.

[0077] The second light shielding layer 28 is arranged below the second optical waveguide part 26, and the second light shielding layer 28 covers the projection area of the coupling-out area on the surface of the second optical waveguide part 26, so as to absorb the light rays transmitted or / and reflected out of the surface of the second optical waveguide part 26 to the maximum extent. That is, the minimum range covered by the second light shielding layer 28 on the projection area of the surface of the second optical waveguide part 26 is the projection area of the coupling-out area on the surface of the optical waveguide 21.

[0078] By setting the size of the grating structure of the coupling-in area 22 and the coupling-out area 23, the distance between the two, the specific structure of the grating, the thickness size of the optical waveguide 21, and the position and size of the first light shielding layer 27 and the second light shielding layer 28, the image light rays can be diffracted and coupled in through the coupling-in area 22, the light rays can be diffracted and transmitted to the coupling-out area 23 through the optical waveguide 21, the light rays transmitted and reflected out of the surface of the optical waveguide 21 are absorbed by the first light shielding layer 27 or the second light shielding layer 28, and the light rays are emitted from the coupling-out area 23 and irradiated to the reflecting unit 3, the light rays are reflected by the reflecting unit 3 to the human eye, and the virtual image of the image is formed in front of the human eye.

[0079] Please refer to Figure 5 , the first optical waveguide part 25 in the optical waveguide unit 2 shown in the embodiment can be arranged on the right side of the second optical waveguide part 26, the image unit 1 is located on the left side of the first optical waveguide part 25, and the first light shielding layer 27 is arranged on the right side of the first optical waveguide part 25. However, it is not limited thereto, please refer to Figure 13 , the image unit 1 is located on the right side of the first optical waveguide part 25, and the first light shielding layer 27 is arranged on the left side of the first optical waveguide part 25.

[0080] Please refer to Figure 14The first light waveguide part 25 in the light waveguide unit 2 shown in the embodiment can be arranged at the left side of the second light waveguide part 26, the image unit 1 is located at the right side of the first light waveguide part 25, and the image light emitted by the image unit 1 is incident from the right side of the first light waveguide part 25. At this time, the first light shielding layer 27 is arranged at the left side of the first light waveguide part 25. Please refer to Figure 15 At this time, the image unit 1 can also be located at the left side of the first light waveguide part 25, and the image light emitted by the image unit 1 is incident from the left side of the first light waveguide part 25. At this time, the first light shielding layer 27 is arranged at the right side of the first light waveguide part 25.

[0081] It should be noted that the positions of the image unit 1, the first light waveguide part 25 and the second light waveguide part 26 are not limited to this, and can be other positions, which are not specifically limited herein.

[0082] Please refer to Figure 16 and Figure 17 The connection between the first light waveguide part 25 and the second light waveguide part 26 can be an arc transition or a straight line transition, or a combination of arc and straight line transition. The specific structure of the connection is not specifically limited herein and can be selected according to actual needs.

[0083] Please refer to Figure 18 and Figure 19 In the embodiment, only one bending light waveguide 21 is shown, that is, the first light waveguide part 25 and the second light waveguide part 26 are included. In fact, the light waveguide 21 can not only include the first light waveguide part 25 and the second light waveguide part 26, but also can include other structures, and can be a two-way or three-way bending light waveguide 21, that is, formed by connecting a plurality of light waveguide parts. The specific structure of the light waveguide 21 is not specifically limited herein.

[0084] Please refer to Figure 20 The light waveguide shown in the embodiment can be applied not only in HUD but also in augmented reality near-eye display, but is not limited to this. The specific application of the light waveguide is not specifically limited herein.

[0085] Please refer to Figure 21 When the light waveguide shown in the embodiment is applied in augmented reality near-eye display, the micro-projection image unit is incident from the first light waveguide part and is emitted from the coupling-out area of the second light waveguide part, and the human eye receives the emitted light, thereby realizing the near-eye display experience of augmented reality.

[0086] Please refer to Figure 22 The application also provides a preparation method for preparing the light waveguide shown above, and the method comprises the following steps:

[0087] S1: preparing a master with a nano structure;

[0088] S2: transferring the nanostructure on the master to the sub-master by a nanoimprint process;

[0089] S3: transferring the nanostructure of the sub-master to at least two optical waveguide parts by a nanoimprint process;

[0090] S4: adding a refractive index matching curing agent in the optical waveguide part to form optical waveguide part adhesion by curing to obtain an optical waveguide.

[0091] The nanostructure can be manufactured on the substrate coated with photoresist by holographic exposure, interference exposure, scanning exposure and the like, thereby forming the master, or can be transferred to the substrate by etching process, and the specific preparation method is prior art, which will not be described here. The specific preparation method of the nanostructure on the master is not listed here. The specific materials and structure sizes of the master and the sub-master are prior art, which will not be described here.

[0092] The curing form of the optical waveguide can be thermal curing, ultraviolet curing, room temperature absorption of moisture in the air curing and the like, which is not specifically limited here.

[0093] The application also provides a vehicle comprising the augmented reality head-up display device as shown above to form a virtual image in front of the windshield. The vehicle can be a bicycle, an electric vehicle, etc., such as a pure electric vehicle, a range-extended electric vehicle, a hybrid electric vehicle, a fuel cell vehicle, a new energy vehicle, etc., which is not specifically limited here.

[0094] In summary, the optical waveguide of the augmented reality head-up display device disclosed in the application comprises at least two optical waveguide parts connected by light, and the planes in which the surfaces of the adjacent two optical waveguide parts are located have an included angle, so that compared with the planar AR-HUD, it has smaller surface area, more reasonable spatial distribution and larger front mounting tolerance. The augmented reality head-up display device has the performance of large field of view, small volume, long virtual image distance, and simple structure, and is suitable for most windshields, and has high mass production universality.

[0095] The technical features of the above-described embodiments can be combined arbitrarily, and to make the description concise, not all possible combinations of the technical features in the above-described embodiments are described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the description.

[0096] The above-described embodiments only express several embodiments of the application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the patent. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the application, a number of modifications and improvements can be made, which are within the scope of the application. Therefore, the protection scope of the patent of the application should be subject to the appended claims.

Claims

1. An augmented reality head-up display device, characterized by comprising: The device comprises an image unit, a light waveguide unit and a reflection unit, the image unit is used to generate image light and direct the image light to the surface of the light waveguide unit, the light waveguide unit conducts the image light and emits it towards the reflection unit, the reflection unit reflects the image light to the human eye and generates a virtual image, the light waveguide unit comprises at least one light waveguide, the light waveguide comprises at least two light-connected light waveguide parts, the planes where the surfaces of the two adjacent light waveguide parts are located have an included angle; The light waveguide comprises a first light waveguide part arranged close to the image unit and a second light waveguide part arranged close to the reflection unit, the light waveguide unit further comprises a first light-shielding layer arranged on one side of the first light waveguide part and a second light-shielding layer arranged on one side of the second light waveguide part, the first light-shielding layer is used to absorb the light transmitted from the first light waveguide part, the second light-shielding layer is used to absorb the light transmitted and / or reflected from the second light waveguide part and the sunlight transmitted from the outside; the first light-shielding layer and the second light-shielding layer have a gap with the light waveguide; The surface of the light waveguide is provided with a coupling-in area and a coupling-out area, the coupling-in area is configured to couple the incident image light into the light waveguide and conduct it along the light waveguide to the coupling-out area, the coupling-out area is configured to emit the image light in the waveguide, the coupling-in area is arranged on the first light waveguide part, and the coupling-out area is arranged on the second light waveguide part.

2. The augmented reality head-up display device of claim 1, wherein, The planes where the surfaces of the two adjacent light waveguide parts are located are perpendicular to each other.

3. The augmented reality head-up display device of claim 1, wherein, The image unit and the first light-shielding layer are arranged on the two sides of the first light waveguide part respectively; the reflection unit and the second light-shielding layer are arranged on the two sides of the second light waveguide part respectively.

4. The augmented reality head-up display device of claim 1, wherein, The absorption rate of the first light-shielding layer and the second light-shielding layer to the visible light waveband is greater than 60%.

5. The augmented reality head-up display device of claim 4, wherein, The projection area of the first light-shielding layer on the surface of the first light waveguide part covers the projection area of the coupling-in area on the surface of the first light waveguide part.

6. The augmented reality head-up display device of claim 4, wherein, The projection area of the second light-shielding layer on the surface of the second light waveguide part covers the projection area of the coupling-out area on the surface of the second light waveguide part.

7. A method of fabricating an optical waveguide in an augmented reality head-up display device as claimed in any one of claims 1-6, characterized in that, The method comprises: S1: preparing a master with nanostructure; S2: transferring the nanostructure on the master to a sub-master by nanoimprint process; S3: transferring the nanostructure of the sub-master to at least two light waveguide parts by nanoimprint process; S4: adding refractive index matching curing agent in the light waveguide part to form light waveguide part adhesion by curing, obtaining light waveguide.

8. A vehicle characterized by comprising: The device comprises an image unit, a light waveguide unit and a reflection unit, the image unit is used to generate image light and direct the image light to the surface of the light waveguide unit, the light waveguide unit conducts the image light and emits it towards the reflection unit, the reflection unit reflects the image light to the human eye and generates a virtual image, the light waveguide unit comprises at least one light waveguide, the light waveguide comprises at least two light-connected light waveguide parts, the planes where the surfaces of the two adjacent light waveguide parts are located have an included angle;

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