CN115903222A - Augmented reality head-up display device, vehicle and preparation method of optical waveguide - Google Patents

Abstract

The utility model relates to an augmented reality new line display device, including image unit, optical waveguide unit and reflection unit, image unit is used for producing image light and guides image light to incide to the surface of optical waveguide unit, the optical waveguide unit conducts image light and jets out towards the reflection unit, the reflection unit reflects image light to people's eye and produces the virtual image, the optical waveguide unit includes at least one deck optical waveguide, the optical waveguide includes the optical waveguide portion of two at least optical connections, adjacent two the plane at optical waveguide portion surface place has the contained angle, thereby compare in plane AR-HUD, it possesses littleer surface area, more reasonable spatial distribution and bigger preceding dress tolerance, this augmented reality new line display device possesses big visual field, little volume, the performance of far away virtual image distance, and simple structure, be applicable to most windshield simultaneously, possess high volume production universality.

Description

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

technical field

The invention relates to a method for preparing an augmented reality head-up display device, a vehicle and an optical waveguide, and belongs to the technical field of display equipment.

Background technique

Head-up display (head up display, HUD) functions as a car information "projector". This technology can project car-related information to the front of the driver's line of sight, thereby reducing the need to look down at the instrument or central control during driving. The frequency of the screen. The traditional HUD is an optical electromechanical coupling component, which is mainly composed of a main control PCB board, a light source, a display medium, an optical mirror group, a DC motor, etc., and the display light source is reflected by multiple mirror structures to reflect information to the On a transparent medium (display screen or windshield), the human eye can see a virtual image that seems to be suspended in front of the eyes. The use of HUD greatly improves driving comfort and safety. It is estimated that the global installed capacity of HUD will reach 15 million units in 2025.

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 its display size and projection distance are limited, and it may cause secondary damage to the driver in the event of a vehicle collision; the display effect of W-HUD is more integrated, but its optical structure It is complex, difficult to design and arrange, occupies a large volume, and its optical principle needs to be matched with a windshield with a complex surface shape, which undoubtedly increases the difficulty of preparation and mass production.

The augmented reality head-up display (AR-HUD) based on optical waveguide, which has emerged in recent years, superimposes digital images on the real environment outside the car, allowing the driver to obtain the visual effect of augmented reality, which can be used for AR navigation, adaptive cruise, driveway, etc. Deviation warning, etc.

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

Contents of the invention

The purpose of the present invention is to provide an augmented reality head-up display device with smaller surface area, more reasonable space distribution and greater front loading tolerance.

To achieve the above object, the present invention provides the following technical solution: an augmented reality head-up display device, comprising an image unit, an optical waveguide unit and a reflection unit, the image unit is used to generate image light and guide the image light to enter the The surface of the optical waveguide unit, the optical waveguide unit guides the image light and emits it toward the reflection unit, the reflection unit reflects the image light to the human eye and generates a virtual image, and the optical waveguide unit includes at least one A layered optical waveguide, the optical waveguide includes at least two optical waveguide parts that are optically connected, and the planes where the surfaces of two adjacent optical waveguide parts are located have an included angle.

Further, the planes where the surfaces of two adjacent optical waveguide parts are located are perpendicular to each other.

Further, the optical waveguide includes a first optical waveguide part disposed close to the image unit and a second optical waveguide part disposed close to the reflection unit, and the optical waveguide unit further includes A first light-shielding layer on one side and a second light-shielding layer arranged on one side of the second optical waveguide, the first light-shielding layer is used to absorb light transmitted from the first light waveguide, and the first light-shielding layer The two light-shielding layers are used for absorbing the light transmitted and/or reflected from the second light waveguide part and the sun light transmitted and entered from the outside.

Further, there is a gap between the first light-shielding layer and the second light-shielding layer and the optical waveguide.

Further, the image unit and the first light-shielding layer are arranged oppositely on both sides of the first light waveguide part; sides.

Further, the absorptivity of the first light-shielding layer and the second light-shielding layer to the visible light band is greater than 60%.

Further, the surface of the optical waveguide is provided with an in-coupling area and an out-coupling area, and the in-coupling area is configured such that the incident image light is coupled into the optical waveguide and guided along the optical waveguide to the The outcoupling region is configured to emit the image light in the waveguide, the incoupling region is arranged on the first optical waveguide part, and the outcoupling region is arranged on the second optical waveguide part. on the optical waveguide.

Further, the projected area of the first light-shielding layer on the surface of the first optical waveguide covers the projected area of the coupling-in region on the surface of the first optical waveguide.

Further, the projected area of the second light-shielding layer on the surface of the second optical waveguide covers the projected area of the outcoupling area on the surface of the second optical waveguide.

The present invention also provides a preparation method for preparing the above-mentioned optical waveguide, the method comprising:

S1: preparing a master plate with a nanostructure;

S2: transferring the nanostructure on the master plate to the daughter plate through a nanoimprint process;

S3: Transfer the nanostructures of the sub-plate to at least two optical waveguide parts through a nanoimprint process;

S4: adding a refractive index matching curing agent to the optical waveguide, and forming the adhesion of the optical waveguide through curing to obtain an optical waveguide.

The present invention also provides a vehicle, including the above-mentioned augmented reality head-up display device.

The beneficial effect of the present invention is that: the optical waveguide of the augmented reality head-up display device shown in the present invention includes at least two optically connected optical waveguide parts, and the planes where the surfaces of two adjacent optical waveguide parts are located have an included angle, so that compared with Planar AR-HUD, which has smaller surface area, more reasonable spatial distribution and greater front loading tolerance, this 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 applicable to most windshields at the same time, with high mass production universality.

The above description is only an overview of the technical solutions of the present invention. In order to understand the technical means of the present invention more clearly and implement them according to the contents of the description, the preferred embodiments of the present invention and accompanying drawings are described in detail below.

Description of drawings

FIG. 1 is a schematic diagram of an optical path of an augmented reality head-up display device with a planar optical waveguide in the prior art;

Fig. 2 is a schematic diagram of the optical path of the planar optical waveguide shown in Fig. 1;

FIG. 3 is a structural schematic diagram of part of the augmented reality head-up display device shown in FIG. 1;

FIG. 4 is a spatial schematic diagram of part of the augmented reality head-up display device shown in FIG. 1;

FIG. 5 is a schematic diagram of an optical path of an augmented reality head-up display device shown in an embodiment of the present application;

FIG. 6 is a spatial schematic diagram of part of the augmented reality head-up display device shown in FIG. 5;

Fig. 7 is a schematic diagram of the light transmission of the planar optical waveguide in Fig. 1 and the optical waveguide in Fig. 5;

Fig. 8 is a schematic diagram of another light transmission of the planar optical waveguide in Fig. 1 and the optical waveguide in Fig. 5;

FIG. 9 is a schematic diagram of a partial optical path of the augmented reality head-up display device shown in FIG. 5 without the first light-shielding layer;

FIG. 10 is a schematic diagram of a partial optical path of the augmented reality head-up display device shown in FIG. 5 with a first light-shielding layer;

FIG. 11 is a schematic diagram of a partial optical path of the augmented reality head-up display device shown in FIG. 5 without a second light-shielding layer;

Fig. 12 is a schematic diagram of a partial light path of the augmented reality head-up display device shown in Fig. 5 with a second light-shielding layer;

FIG. 13 is a schematic diagram of another structural light path of a part of the augmented reality head-up display device shown in FIG. 5;

Fig. 14 is a schematic diagram of a third structural light path of part of the augmented reality head-up display device shown in Fig. 5;

Fig. 15 is a schematic diagram of a fourth structural light path of part of the augmented reality head-up display device shown in Fig. 5;

Fig. 16 is a schematic structural diagram of the connection shown in Fig. 5;

Fig. 17 is another structural schematic diagram of the joint shown in Fig. 5;

FIG. 18 is another structural schematic diagram of the image unit and the optical waveguide shown in FIG. 5;

FIG. 19 is a schematic diagram of a third structure of the image unit and the optical waveguide shown in FIG. 5;

FIG. 20 is a schematic structural diagram of the application of the optical waveguide shown in FIG. 5 in augmented reality near-eye display;

FIG. 21 is a schematic diagram of the optical path of the optical waveguide shown in FIG. 20 applied in augmented reality near-eye display;

Fig. 22 is a flowchart of a method for preparing the optical waveguide shown in Fig. 5 shown in an embodiment of the present application;

Fig. 23 is a graph showing the relationship between the light absorption, reflection and transmission efficiency of the optical waveguide and the wavelength.

Detailed ways

The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are some of the embodiments of the present invention, but not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" etc. The indicated orientation or positional relationship is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the referred mechanism or element must have a specific orientation, and must have a specific orientation. construction and operation, therefore, should not be construed as limiting the invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and should not be construed as indicating or implying relative importance.

In addition, the technical features involved in the different embodiments of the present invention described below may be combined with each other as long as there is no conflict with each other.

Please refer to FIG. 5 , which shows an augmented reality head-up display device according to an embodiment of the present invention, which includes an image unit 1 , an optical 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 optical waveguide unit 2 . The light waveguide unit 2 guides the image light while increasing the dilation of the exit pupil, and emits it toward the reflection unit 3 . The image light emitted by the optical waveguide unit 2 is irradiated onto the reflective unit 3 , and the reflective unit 3 reflects the image light irradiated thereon to human eyes to generate a virtual image.

The principle of the head-up display of the augmented reality head-up display device is as follows: the image unit 1 emits image light with a certain field of view, the image light enters the optical waveguide unit 2, and exits after the exit pupil of the optical waveguide unit 2 expands, and the outgoing image light passes through the reflection unit 3 is reflected to the human eye at a certain reflection angle, and the human eye can see a virtual image at a certain projection distance through the reflection unit 3 .

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

7 and 8, the surface of the optical waveguide 21 is provided with an in-coupling area 22 and an out-coupling area 23, and the in-coupling area 22 is configured so that the incident image light is coupled into the optical waveguide 21 and guided along the optical waveguide 21 to The outcoupling region 23 is configured to emit the image light in the waveguide. The image light passes through the in-coupling area 22, and is diffracted and totally reflected inside the optical waveguide 21. The diffracted and totally reflected image light passes through the optical waveguide 21 for multiple transmissions, and the image light covers the entire out-coupling area 23 and passes through the out-coupling area 23. ejected to achieve exit pupil dilation. The light coupled in by the optical waveguide 21 can be continuously transmitted to a specific direction under the condition of satisfying total reflection, and the transmittance of the optical waveguide 21 is greater than 80%. The optical waveguide 21 can be made of glass, resin, or the transmittance under visible light is greater than 80% of the materials are not listed here. The thickness of the optical waveguide 21 is less than 2mm, and the specific thickness of the optical waveguide 21 is not specifically limited here, and can be set according to actual needs.

The in-coupling region 22 and the out-coupling region 23 are structural units with diffractive characteristics, which are essentially nanostructures that have a refractive index gradient and can realize light diffraction conduction. Specifically, both the in-coupling region 22 and the out-coupling region 23 are periodic gratings Structures, such as nanoscale embossed gratings or volume holographic gratings, periodic grating structures can be fabricated directly on the optical waveguide 21, or pre-fabricated on the film, and then the film carrying the grating structure is combined with the optical waveguide 21. The bottom of the grating structure forming the incoupling region 22 and the outcoupling region 23 may be located on the surface of the optical waveguide 21 or within the optical waveguide 21 .

Both the in-coupling area 22 and the out-coupling area 23 may be rectangular, wherein the in-coupling area 22 may also adopt a circular or other shape, depending on requirements. The grating structure can be prepared by holographic interference technology, photolithography technology or nanoimprint technology, which can be freely selected according to actual needs.

The coupling-in area 22 is preferably an inclined relief grating, and the image light is incident at the position of the coupling-in area 22 and is coupled into the optical waveguide 21 through a diffraction process. The inclined diffraction grating has selectivity to wavelength, avoids dispersion, and has higher diffraction efficiency for a certain wavelength band. The period and orientation of the grating structure in the outcoupling region 23 are consistent with the grating in the incoupling region 22, which can be a positive grating or an oblique grating.

By designing parameters such as the period, depth, duty cycle and tilt angle of the grating structure, the light of a specific wavelength or band can be efficiently selected to realize the wavelength selective function. For example, the green image light is coupled, then bent and transmitted in the waveguide, and the blue and red image light are not affected, so that single-channel light diffraction is realized. Or perform high-efficiency selection of light in the blue and red bands to achieve dual-channel light diffraction. The single-channel diffractive optical waveguide 21 only transmits the image light of a certain color, and the image light of other colors passes through the optical waveguide 21, so that the light does not interfere with each other.

In addition, a turning area (not shown) may also be provided on the surface of the optical waveguide 21 , and the turning area is used to change the propagation direction of the image light in the optical waveguide 21 . When the image light is incident on the in-coupling area 22, the image light is totally reflected to the turning area in the optical waveguide 21, and the turning area changes the propagation direction of the image light, so that the changed direction of the image light is totally reflected to the out-coupling area 23, which can The output image is effectively dilated, thereby expanding the range of viewing angles and better meeting user needs.

Please refer to Figure 1. In the planar AR-HUD solution in the prior art, the image unit 1 emits image light with a certain field of view, and after the exit pupil of the optical waveguide unit 2 expands, it is reflected to the human eye by the reflection unit 3. A virtual image is formed, but this optical waveguide 21 is a planar optical waveguide 21 .

Please refer to Fig. 2, the coupling-in region 22 and the coupling-out region 23 of the planar optical waveguide 21 are arranged on both sides of the same surface of the optical waveguide 21 or both sides of different surfaces along the same axis, the coupling of the planar optical waveguide 21 The in-coupling region 22 and the out-coupling region 23 are located on the same surface of the optical waveguide 21 with a space between them. The light passes through the in-coupling region 22 , and undergoes diffraction and total reflection inside the waveguide. The diffracted and total-reflected light passes through the waveguide for multiple times, and the light covers the entire out-coupling region 23 , thereby achieving exit pupil expansion.

Please refer to FIG. 3 and FIG. 4 , the transmission of the optical waveguide 21 needs to input the image light emitted by the image unit 1 from the in-coupling area 22 , and then enter the out-coupling area 23 through the pupil expansion of the waveguide. Because the in-coupling area 22 and the out-coupling area 23 are horizontally tiled, only the out-coupling light of the out-coupling area 23 is transmitted to the reflection unit 3, and the in-coupling area 22 does not participate in the outgoing light to the reflection unit 3, that is, eye movement The range corresponds to the range of the outcoupling region 23 of the optical waveguide 21 . In order to obtain a larger range of eye movement, it is necessary to increase the surface area of the optical waveguide 21. At the same time, during the transmission process of the optical waveguide 21, the in-coupling region 22 and the out-coupling region 23 need a certain conduction space. This part of the space plus the surface area that needs to be increased, It will take up a lot of space and affect the feasibility of HUD front installation.

Please refer to Fig. 5, Fig. 7 and Fig. 8, in order to reduce the space occupied by the optical waveguide unit 2 and improve the feasibility of HUD front-loading, in this embodiment, the optical waveguide 21 includes at least two optically connected optical waveguide parts, adjacent The planes where the surfaces of the two optical waveguide parts are located have an included angle, and the included angle is greater than 0° and less than 180°, that is, the planes where the surfaces of two adjacent optical waveguide parts are located are not parallel. In this embodiment, the planes where the surfaces of two adjacent optical waveguides are located are perpendicular to each other. It should be noted that the adjacent optical waveguide parts can be bonded and fixed by curing agent or adhesive, or the adjacent optical waveguide parts are integrally formed, and the light enters the adjacent optical waveguide from one optical waveguide part When part, all the light can pass through, that is, the optical characteristics of the adhesive layer arranged between the adjacent waveguide parts are consistent with the waveguide part.

The optical waveguide 21 includes a first optical waveguide portion 25 disposed close to the image unit 1 and a second optical waveguide portion 26 disposed adjacent to the reflection unit 3, and the planes where the surfaces of the first optical waveguide portion 25 and the second optical waveguide portion 26 are located 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 , and the following two optical waveguide portions are taken as an example to describe in detail.

In this embodiment, the incoupling region 22 is arranged on the first optical waveguide part 25 , and the outcoupling region 23 is arranged on the second optical waveguide part 26 . Specifically, the incoupling region 22 and the image unit 1 are arranged on the same side of the first optical waveguide 25 , and the outcoupling region 23 and the reflection unit 3 are arranged on the same side of the second optical waveguide 26 . The principle of transmission of the optical waveguide 21 is: the image light emitted by the image unit 1 is incident on the in-coupling area 22 of the first optical waveguide part 25, and after being diffracted by the in-coupling area 22, it is totally reflected and transmitted in the first optical waveguide part 25. The light transmitted to the outcoupling region 23 of the second optical waveguide part 26 is coupled out to the reflection unit 3 through the outcoupling region 23 , and reflected to human eyes through the reflection unit 3 .

Please refer to FIG. 7 , where the solid line part is the light transmission diagram of the optical waveguide 21 in this embodiment, and the dotted line is the light transmission diagram of the planar optical waveguide 21 . In the optical waveguide 21 of this embodiment, the image light shown by the solid line part emitted by the image unit 1 is diffracted by the in-coupling region 22, and the diffracted light is totally reflected and transmitted in the optical waveguide 21. When transmitted to the first optical waveguide part 25 and the second optical waveguide portion 26, the light can directly enter the second optical waveguide portion 26 from the first optical waveguide portion 25 at a total reflection angle, thereby continuing to be totally reflected in the second optical waveguide portion 26 and transmitted to the The outcoupling area 23 is emitted to the reflective unit 3 through the outcoupling area 23 .

In the planar optical waveguide 21, assuming the same in-coupling region 22, out-coupling region 23 and image unit 1, the image light shown in the dotted line part emitted by the image unit 1 is diffracted through the in-coupling region 22, and the diffraction angle Same as the light shown by the solid line, the diffracted light is totally reflected by the planar optical waveguide 21 and then transmitted to the outcoupling region 23 , and then exits to the reflection unit 3 through the outcoupling region 23 .

It can be seen that the angles of the light shown by the solid line and the light shown by the dotted line are the same when they enter the outcoupling region 23, which means that the optical waveguide 21 shown in this embodiment is compared with the planar optical waveguide 21. There is no essential change in the direction of the light, and at the same time, the transmission and bending of the light in the optical waveguide 21 can be realized.

Please refer to FIG. 8 , which is the same as FIG. 7 , the solid line part is the light transmission situation in the optical waveguide 21 in this embodiment, and the dotted line is the light transmission situation in the planar optical waveguide 21 . In the optical waveguide 21 of this embodiment, the image light shown by the solid line part emitted by the image unit 1 is diffracted by the in-coupling region 22, and the diffracted light is totally reflected and transmitted in the optical waveguide 21. When transmitted to the first optical waveguide part 25 and the junction of the second optical waveguide 26, the light from the first optical waveguide 25 is incident to the side of the second optical waveguide 26 at a total reflection angle, and due to the total reflection in the optical waveguide 21, the light will continue to The reflection process reflects to the upper surface of the second optical waveguide part 26, and then conducts in the second optical waveguide part 26 after being totally reflected by the upper surface, so as to continue the total reflection in the second optical waveguide part 26 and conduct to the outcoupling region 23, The output is emitted to the reflective unit 3 through the outcoupling region 23 .

In the planar optical waveguide 21, assuming the same in-coupling region 22, out-coupling region 23 and image unit 1, the image light shown in the dotted line part emitted by the image unit 1 is diffracted through the in-coupling region 22, and the diffraction angle Same as the light shown by the solid line, the diffracted light is totally reflected by the planar optical waveguide 21 and then transmitted to the outcoupling region 23 , and then exits to the reflection unit 3 through the outcoupling region 23 .

The light conduction in the planar waveguide is exactly the same as that shown in FIG. Consistent means that compared with the planar optical waveguide 21, the optical waveguide 21 shown in this embodiment has no essential change in the direction of the light, and at the same time, the light transmission and bending in the optical waveguide 21 can be realized.

Please refer to FIG. 6 , in order to increase the range of eye movements, it is only necessary to increase the range of the outcoupling region 23 located in the second optical waveguide part 26 , while increasing the range of the incoupling region 22 does not need to increase the range of the second optical waveguide part 26 . The size of the surface does not increase too much space requirements, which greatly reduces the requirements for the front surface area of the HUD.

Please refer to FIG. 5 , the optical waveguide unit 2 further includes a first light shielding layer 27 disposed on the first light waveguide portion 25 side and a second light shielding layer 28 disposed on the second light waveguide portion 26 side, the first light shielding layer 27 The second light-shielding layer 28 is used to absorb light transmitted and/or reflected from the second light waveguide 26 and sunlight transmitted from the outside. In this embodiment, the image unit 1 and the first light-shielding layer 27 are disposed on opposite sides of the first optical waveguide portion 25 ;

There is a gap between the first light-shielding layer 27 and the second light-shielding layer 28 and the optical waveguide 21 to absorb light transmitted or reflected from the light waveguide 21 and avoid absorbing light inside the light waveguide 21 . The details of the gap are not specifically 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 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 a structure with an absorption rate for the visible light band greater than 60% or for visible light. Materials with an absorption rate of more than 60% in the wave band are prepared, and the specific materials and structures are not listed here, and can be selected according to actual needs.

Please refer to FIG. 9 and FIG. 10, if the optical waveguide unit 2 is not provided with the first light-shielding layer 27, even after the image light guided in the optical waveguide 21 passes through multiple optical waveguides 21, part of the image light will still pass through the optical waveguide 21. In particular, no matter whether the image light is incident vertically or obliquely to the in-coupling region, only part of the light will be diffracted and transmitted in the optical waveguide 21 , and the 0th order diffracted light will pass through the optical waveguide 21 and exit. This part of the image light will be reflected or diffusely reflected by any reflective surface, and the reflected or diffusely reflected light will be incident into the optical waveguide 21 again, introducing stray light and affecting the image quality. Please refer to FIG. 23 , in the visible light band, when the image light enters the in-coupling region 22, part of the light will be transmitted out, wherein, as the wavelength of the image light increases, the reflection efficiency of the optical waveguide 21 for the image light gradually increases. While the transmission efficiency decreases gradually, the absorption efficiency is always close to zero. While the optical waveguide unit 2 is provided with a first light-shielding layer 27, the first light-shielding layer 27 absorbs the image light emitted through the light waveguide 21, preventing it from re-incidence into the light waveguide 21 after reflection or diffuse reflection, thereby weakening the Interference improves image quality.

The projected area of the first light shielding layer 27 on the surface of the first optical waveguide 25 covers the projected area of the in-coupling area on the surface of the first optical waveguide 25 , so as to absorb the light transmitted from the surface of the first optical waveguide 25 to the maximum. That is, the projection area of the first light-shielding layer 27 on the surface of the first optical waveguide 25 covers a minimum range of the projection area of the in-coupling area on the surface of the first optical waveguide 25 .

11 and 12, if the optical waveguide unit 2 is not provided with the second light-shielding layer 28, even if the image light guided in the optical waveguide 21 passes through multiple optical waveguides 21, it will face each other in the outcoupling area (not shown). The light transmitted from one side of the reflective unit 3 and the external solar light will also enter the optical waveguide 21 after passing through the reflective unit 3, and then transmit the light from the side of the outcoupling area opposite to the reflective unit 3, that is, the sun’s rays will also flow backwards. Reverse conduction in the waveguide 21 causes temperature rise and damage to key components. At the same time, when the image light enters the optical waveguide 21, some light will also be reflected by the surface of the optical waveguide 21. These light rays will be reflected or diffusely reflected by any surface with reflective properties, and the reflected or diffusely reflected light will be incident on the optical waveguide again. In the optical waveguide 21, stray light is introduced, which affects the imaging quality. While the light waveguide unit 2 is provided with a second light-shielding layer 28, the second light-shielding layer 28 absorbs these three parts of light, preventing it from re-incidence into the light waveguide 21 or reverse conduction after reflection or diffuse reflection, thereby weakening the influence. Improved image quality.

The second light shielding layer 28 is arranged below the second light waveguide portion 26, and the projection area of the second light shielding layer 28 on the surface of the second light waveguide portion 26 covers the projection area of the outcoupling region on the surface of the second light waveguide portion 26, thereby maximizing Light transmitted or/and reflected from the surface of the second optical waveguide 26 is absorbed to a maximum extent. That is, the minimum range covered by the projected area of the second light shielding layer 28 on the surface of the second optical waveguide 26 is the projected area of the outcoupling area on the surface of the optical waveguide 21 .

By setting the size of the grating structure of the coupling-in region 22 and the coupling-out region 23, the distance between them, the specific structure of the grating, the thickness dimension of the optical waveguide 21, and the positions and positions of the first light-shielding layer 27 and the second light-shielding layer 28 The size of the image light can be diffracted in through the in-coupling area 22, the light is diffracted by the optical waveguide 21 and transmitted to the out-coupling area 23, and the light transmitted and reflected by the surface of the optical waveguide 21 is captured by the first light-shielding layer 27 or the second light-shielding layer 27. The light-shielding layer 28 absorbs and emits from the outcoupling region 23 and irradiates the reflection unit 3 , and the light is reflected by the reflection unit 3 to the human eye to form a virtual image of the image in front of the human eye.

Please refer to FIG. 5, the first optical waveguide part 25 in the optical waveguide unit 2 shown in this 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, The first light shielding layer 27 is provided on the right side of the first optical waveguide portion 25 . But not limited thereto, please refer to FIG. 13 , the image unit 1 is located on the right side of the first optical waveguide portion 25 , and the first light shielding layer 27 is disposed on the left side of the first optical waveguide portion 25 .

Please refer to FIG. 14, the first optical waveguide part 25 in the optical waveguide unit 2 shown in this embodiment can be arranged on the left side of the second optical waveguide part 26, the image unit 1 is located on the right side of the first optical waveguide part 25, The image light emitted by the image unit 1 is incident from the right side of the first optical waveguide 25 , and at this time, the first light shielding layer 27 is disposed on the left side of the first optical waveguide 25 . Please refer to FIG. 15. At this time, the image unit 1 may also be located on the left side of the first optical waveguide 25, and the image light emitted by the image unit 1 is incident from the left side of the first optical waveguide 25. At this time, the first light-shielding layer 27 is provided on the right side of the first optical waveguide portion 25 .

It should be noted that the positions of the image unit 1 and the first optical waveguide portion 25 and the second optical waveguide portion 26 are not limited to this, but can also be other positions, which are not specifically limited here.

Please refer to Fig. 16 and Fig. 17, the connection between the first optical waveguide part 25 and the second optical waveguide part 26 can be an arc transition or a straight line transition, or a combination of arc and straight line transition, as for the specific structure of the connection, here It is not specifically limited, and can be selected according to actual needs.

Please refer to FIG. 18 and FIG. 19 , in this embodiment, only one bend of the optical waveguide 21 is shown, that is, including the first optical waveguide portion 25 and the second optical waveguide portion 26 . In fact, the optical waveguide 21 may not only include the first optical waveguide portion 25 and the second optical waveguide portion 26, but may also include other structures, and may also be a two-way or three-way bending optical waveguide 21, that is, a plurality of optical waveguide portions A connection is formed. The specific structure of the optical waveguide 21 is not specifically limited here.

Please refer to FIG. 20 , the optical waveguide shown in this embodiment is not only applied in HUD, but also can be applied in augmented reality near-eye display, but it is not limited thereto. The specific application of the optical waveguide is not specifically limited here.

Please refer to Fig. 21. When the optical waveguide shown in this embodiment is applied in the near-eye display of augmented reality, the micro-projection image unit is incident from the first optical waveguide part, exits from the outcoupling area of the second optical waveguide part, and the human eyes receive emit light, thereby realizing the near-eye display experience of augmented reality.

Please refer to FIG. 22 , the present application also provides a preparation method for preparing the above-mentioned optical waveguide, and the method also includes:

S1: preparing a master plate with a nanostructure;

S2: Transfer the nanostructure on the master plate to the daughter plate through the nanoimprint process;

S3: Transfer the nanostructures of the daughter plate to at least two optical waveguide parts through a nanoimprint process;

S4: adding a refractive index matching curing agent to the optical waveguide, and forming the adhesion of the optical waveguide through curing to obtain an optical waveguide.

Among them, the nanostructure can be manufactured on the substrate coated with photoresist by holographic exposure, interference exposure, scanning exposure and other methods to form a master plate, and can also be transferred to the substrate by etching process. The specific preparation method is the prior art. I won't repeat them here. The specific preparation methods of the nanostructures on the master are not listed here. The specific materials and structural dimensions of the master plate and the sub-plate are all in the prior art, and will not be repeated here.

The curing method used to form the optical waveguide may be heat curing, ultraviolet curing, room temperature curing by absorbing moisture in the air, etc., which are not specifically limited here.

The present application also provides a vehicle, including the augmented reality head-up display device as shown above, forming a virtual image in front of the windshield. The vehicle may be a bicycle, an electric vehicle, etc., for example, a pure electric vehicle, an extended-range electric vehicle, a hybrid electric vehicle, a fuel cell vehicle, a new energy vehicle, etc., which are not specifically limited.

To sum up, the optical waveguide of the augmented reality head-up display device shown in the present invention includes at least two optically connected optical waveguide parts, and the planes where the surfaces of two adjacent optical waveguide parts are located have an included angle, so compared with the planar AR- HUD, which has a smaller surface area, a more reasonable spatial distribution and a larger front-loading tolerance, the augmented reality head-up display device has the performance of a large field of view, a small volume, a far virtual image distance, and a simple structure, and is also suitable for Most windshields have high mass production universality.

The technical features of the above-mentioned embodiments can be combined arbitrarily. To make the description concise, all possible combinations of the technical features in the above-mentioned embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, should be considered as within the scope of this specification.

The above-mentioned embodiments only express several implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but should not be construed as limiting the patent scope of the invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent for the present invention should be based on the appended claims.

Claims (11)

1. An augmented reality head-up display device, characterized in that it comprises an image unit, an optical 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 optical waveguide unit, The optical waveguide unit guides the image light and emits it toward the reflection unit, and the reflection unit reflects the image light to human eyes and generates a virtual image. The optical waveguide unit includes at least one layer of optical waveguides, the The optical waveguide includes at least two optically connected optical waveguide parts, and the planes where the surfaces of two adjacent optical waveguide parts are located have an included angle. 2 . The augmented reality head-up display device according to claim 1 , wherein planes where two adjacent surfaces of the light waveguide parts are located are perpendicular to each other. 3 . 3. The augmented reality head-up display device according to claim 1, wherein the optical waveguide comprises a first optical waveguide part arranged close to the image unit and a second light waveguide part arranged close to the reflection unit, The optical waveguide unit further includes a first light shielding layer disposed on one side of the first light waveguide part and a second light shielding layer disposed 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, the second light-shielding layer is used to absorb the light transmitted and/or reflected from the second light waveguide and the sunlight transmitted from the outside. 4 . The augmented reality head-up display device according to claim 3 , wherein there is a gap between the first light-shielding layer and the second light-shielding layer and the optical waveguide. 5. The augmented reality head-up display device according to claim 3, wherein the image unit and the first light-shielding layer are relatively arranged on both sides of the first light waveguide; the reflection unit and the first light-shielding layer The second light-shielding layer is oppositely arranged on two sides of the second optical waveguide part. 6 . The augmented reality head-up display device according to claim 3 , wherein the absorptivity of the first light-shielding layer and the second light-shielding layer to the visible light band is greater than 60%. 7. The augmented reality head-up display device according to claim 3, wherein the surface of the optical waveguide is provided with an in-coupling area and an out-coupling area, and the in-coupling area is configured such that the incident image light is coupled into the optical waveguide and guided along the optical waveguide to the outcoupling region, the outcoupling region is configured to emit the image light in the waveguide, and the incoupling region is set on the first On the optical waveguide portion, the outcoupling region is provided on the second optical waveguide portion. 8. The augmented reality head-up display device according to claim 7, characterized in that, the projection area of the first light-shielding layer on the surface of the first optical waveguide covers the in-coupling area on the surface of the first optical waveguide. projection area on the surface. 9. The augmented reality head-up display device according to claim 7, characterized in that, the projected area of the second light-shielding layer on the surface of the second optical waveguide covers the outcoupling area on the surface of the second optical waveguide. projection area on the surface. 10. A method for preparing the optical waveguide according to any one of claims 1-9, characterized in that the method comprises: S1: preparing a master plate with a nanostructure; S2: transferring the nanostructure on the master plate to the daughter plate through a nanoimprint process; S3: Transfer the nanostructures of the sub-plate to at least two optical waveguide parts through a nanoimprint process; S4: adding a refractive index matching curing agent to the optical waveguide, and forming the adhesion of the optical waveguide through curing to obtain an optical waveguide. 11. A vehicle, characterized by comprising the augmented reality head-up display device according to any one of claims 1-9.

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