CN215375952U

CN215375952U - Augmented reality head-up display device and vehicle

Info

Publication number: CN215375952U
Application number: CN202121816715.6U
Authority: CN
Inventors: 罗明辉; 乔文; 成堂东; 李瑞彬; 陈林森
Original assignee: SVG Tech Group Co Ltd
Current assignee: SVG Tech Group Co Ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2021-12-31
Anticipated expiration: 2031-08-05

Abstract

The utility model relates to an augmented reality new line display device and vehicle, including the image element, optical waveguide unit and reflection unit, the reflection unit is including the transparent piece that has the reflection function and the multispectral reflection stratum of setting on the transparent piece, the transparent piece includes the transparent plate of at least two-layer range upon range of setting, multispectral reflection stratum sets up on the first transparent plate that is close to the optical waveguide unit, the multispectral reflection stratum possesses the high reflectivity of certain bandwidth to red green blue multiband light, make less image light pass through first light-passing board and incide other transparent plates, thereby can effectively eliminate the ghost image phenomenon, improve the quality and the efficiency of display image, and simultaneously, this multispectral reflection stratum carries out the high reflection to red green blue dominant wave department narrower bandwidth, partial light has been passed through, avoid all light to all be reflected, thereby avoid producing mirror effect, improve the security performance.

Description

Augmented reality head-up display device and vehicle

Technical Field

The utility model relates to an augmented reality head-up display device and a vehicle, and belongs to the technical field of display equipment.

Background

The traditional HUD is an optical-mechanical-electrical coupling component and mainly comprises a main control PCB board, a light source, a display medium, an optical lens group, a direct current motor and the like, wherein the display light source reflects information to a transparent medium (a display screen or windshield) through multiple mirror surface structures, so that human eyes see virtual images which are suspended in front of the eyes.

Currently mainstream HUDs are largely classified into a combination type (C-HUD) and a windshield type (W-HUD) according to product forms. Technically, the C-HUD has a simple optical structure and is relatively easy to design, but the display size and the projection distance are limited, and secondary damage to a driver can be caused when a vehicle collides; the W-HUD display effect is more integrated, but its optical structure is complicated, and the design is higher with arranging the degree of difficulty, and it is bulky to occupy, and its optical principle needs the windshield of cooperation complex face type, has increased preparation and volume production degree of difficulty undoubtedly.

The augmented reality head-up display (AR-HUD) realized based on the optical waveguide which is started in recent years superposes the digital image on the real environment outside the vehicle, so that the driver obtains the visual effect of augmented reality, and the method can be used for AR navigation, self-adaptive cruise, lane departure early warning and the like.

Compared with the current mainstream C-HUD and W-HUD, the AR-HUD has the characteristics of small volume, long projection distance, large field angle, high universality and the like. In the prior art, because windshield generally adopts bilayer structure, therefore light can cause the secondary reflection through windshield, forms the vision ghost image, greatly brings the visual experience discomfort.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide an augmented reality head-up display device which can effectively eliminate double images and improve the quality and efficiency of displayed images.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides an augmented reality new line display device, includes image element, optical waveguide unit and reflection unit, the image element is used for producing image light and guides image light incides extremely the surface of optical waveguide unit, the optical waveguide unit will image light conduction and orientation the reflection unit jets out, the reflection unit will image light reflects to people's eye and produces the virtual image, the reflection unit is in with the setting including the transparency with reflection function multispectral reflection stratum on the transparency, the transparency includes the transparent plate of two-layer range upon range of setting at least, multispectral reflection stratum sets up and is being close to on the first transparent plate of optical waveguide unit.

Further, the multispectral reflective layer comprises at least one low refractive index layer and at least one high refractive index layer, the multispectral reflective layer being expressible as (LH) ^ m, where L is the low refractive index layer, H is the high refractive index layer, m is the number of stacking cycles, and the refractive index of the high refractive index layer differs from the refractive index of the low refractive index layer by at least 0.1.

Further, the thickness range of the low refractive index layer is 0-300 nm; the thickness range of the high-refractive-index layer is 0-100 nm; the number m of the laminating cycles is 2-50, and the thickness range of the first low-refractive-index layer close to the first transparent plate is larger than 0.

Further, the refractive index range of the low refractive index layer is 1.3-1.78; the refractive index range of the high refractive index layer is 1.8-2.9.

Further, the material of the low refractive index layer is any one of silicon oxide, aluminum oxide and magnesium fluoride; the material of the high refractive index layer is any one of titanium oxide, iron oxide, niobium oxide, tantalum oxide, zirconium oxide, chromium oxide, cerium oxide and cobalt oxide.

Further, a matching layer is arranged between the multispectral reflecting layer and the first transparent plate, and the refractive index of the matching layer is 2.0-2.9.

Further, the multispectral reflecting layer comprises a substrate layer and a microstructure layer formed on the substrate layer, the microstructure layer comprises a plurality of microstructures which are repeatedly arranged, each microstructure comprises at least three microstructure units, the width of each microstructure unit is different, each microstructure unit comprises a protrusion and a groove which is adjacent to the protrusion, the width range of the protrusion is 100-400 nm, the height range of the protrusion is 50-300 nm, and the width range of the groove is 50-300 nm.

Further, the refractive index of the substrate layer and the refractive index of the microstructure layer are 1.4-1.7, and the substrate layer and the microstructure layer are made of any one of flexible acrylic, resin and plastic.

Further, the transparent piece is a double-layer windshield.

Furthermore, the optical waveguide unit comprises at least one optical waveguide, a first shading layer arranged on one side of the optical waveguide and a second shading layer arranged on the other side of the optical waveguide, wherein the first shading layer is used for absorbing light transmitted out of the optical waveguide, and the second shading layer is used for absorbing light transmitted and/or reflected out of the optical waveguide and solar light transmitted and entering from the outside.

The utility model also provides a vehicle comprising the augmented reality head-up display device.

The utility model has the beneficial effects that: the augmented reality head-up display device disclosed by the utility model is provided with the multispectral reflecting layer with a certain bandwidth and high reflectivity for red, green and blue multiband light on the first transparent plate close to the optical waveguide unit, and the multispectral reflecting layer is used for reflecting image light, so that less image light is transmitted to other transparent plates through the first transparent plate, the ghost phenomenon can be effectively eliminated, and the quality and the efficiency of displayed images are improved.

Meanwhile, the multispectral reflecting layer highly reflects the narrower bandwidth at the red, green and blue main wave section, and all light rays are prevented from being reflected by partial light rays, so that the mirror effect is avoided, and the safety performance is improved.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical solutions of the present invention more clearly understood and to implement them in accordance with the contents of the description, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.

Drawings

Fig. 1 is a schematic optical path diagram of an augmented reality head-up display device according to an embodiment of the present application;

FIG. 2 is a schematic diagram of an optical path of a reflection unit of an augmented reality head-up display device in the prior art;

FIG. 3 is a schematic diagram of an optical path of the reflection unit shown in FIG. 2 for forming a ghost effect;

FIG. 4 is a schematic optical path diagram of a portion of the augmented reality heads-up display device shown in FIG. 1;

FIG. 5 is a schematic optical path diagram of the partial augmented reality heads-up display apparatus shown in FIG. 1 for ghost elimination;

FIG. 6 is a simulation graph of reflection efficiency versus wavelength effect of the multi-spectral reflective layer obtained in the first embodiment;

FIG. 7 is a schematic diagram of a structure of the multi-spectral reflective layer of FIG. 1;

FIG. 8 is a simulation graph of the reflection efficiency versus wavelength effect of the multispectral reflecting layer obtained in the second embodiment.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within 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", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the mechanism or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to 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 they do not conflict with each other.

Referring to fig. 1, an augmented reality head-up display device according to an embodiment of the present application includes an image unit 1, an optical waveguide unit 2, and a reflection unit 3. The image unit 1 serves to generate image light and guide the image light to be incident on the surface of the light guide unit 2. The light guide unit 2 guides the image light while increasing the exit pupil expansion, and exits toward the reflection unit 3. The image light emitted from the optical waveguide unit 2 is irradiated onto the reflection unit 3, and the reflection unit 3 reflects the image light irradiated thereon to human eyes and generates a virtual image.

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

The optical waveguide unit 2 includes at least one optical waveguide 21, which may be one optical waveguide 21, two optical waveguides 21, or three optical waveguides 21, etc. in this embodiment, the optical waveguide unit 2 includes three stacked optical waveguides 21, and the number of layers of the optical waveguides 21 is not specifically limited herein and may be set according to actual needs.

The surface of the optical waveguide 21 is provided with a coupling-in area (not shown) configured such that incident image light is coupled into the optical waveguide 21 and conducted along the optical waveguide 21 to the coupling-out area (not shown) configured to emit the image light in the optical waveguide 21. The image light passes through the coupling-in area and is diffracted and totally reflected inside the light guide 21, the diffracted and totally reflected image light is conducted for multiple times through the light guide 21, and the image light is distributed on the whole coupling-out area and is emitted out of the coupling-out area, so that the exit pupil expansion is realized. The light guide 21 can continuously transmit the coupled light to a specific direction under the condition of satisfying total reflection, the transmittance of the light guide 21 is greater than 80%, and the light guide 21 can be glass, resin or a material with transmittance of greater than 80% under visible light, which is 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 herein and can be set according to actual needs.

The coupling-in region and the coupling-out region are structural units with diffraction characteristics, and are essentially nano structures which have refractive index gradients and can realize light diffraction and conduction, specifically, the coupling-in region and the coupling-out region are both periodic grating structures, such as nanoscale relief gratings or volume holographic gratings, the periodic grating structures can be directly manufactured on the optical waveguide 21, or can be manufactured on a film in advance, and then the film with the grating structures is combined with the optical waveguide 21. The bottom of the grating structure forming the coupling-in and coupling-out regions may be located on the surface of the optical waveguide 21 or within the optical waveguide 21.

The coupling-in area and the coupling-out area may both be rectangular, wherein the coupling-in area may also take a circular or other shape, as desired. The coupling-in region and the coupling-out region are arranged along the same axis on both sides of the same plane of the optical waveguide 21 or on both sides of different planes, and in this embodiment, the coupling-in region and the coupling-out region are located on the same surface of the optical waveguide 21 with a space therebetween. The grating structure can be prepared by adopting a holographic interference technology, a photoetching technology or a nano-imprinting technology, and can be freely selected according to actual needs.

The coupling-in region is preferably an inclined relief grating, at the location of which the image light is incident and is coupled into the light guide 21 by a diffraction process. The diffraction grating arranged obliquely has selectivity on wavelength, avoids dispersion and has higher diffraction efficiency aiming at a certain wavelength band. The period and orientation of the grating structure of the outcoupling region coincide with the grating of the incoupling region, which may be a positive grating or a slanted grating.

By designing parameters such as the period, the depth, the duty ratio, the inclination angle and the like of the grating structure, light with specific wavelength or waveband is selected efficiently, and the wavelength selectivity function is realized. For example, green image light is coupled and then bent and conducted in the waveguide, so that blue and red image light is not affected, and single-channel light diffraction is realized. Or the light of blue and red wave bands is selected with high efficiency, and the dual-channel light diffraction is realized. The light guide 21 with single-channel diffraction only conducts certain color image light, and the rest color image light passes through the light guide 21, so that the light rays are not interfered with each other.

In addition, the surface of the optical waveguide 21 may be provided with a turning region (not shown) for changing the propagation direction of the image light in the optical waveguide 21. When the image light is incident into the coupling-in area, 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 image light with the changed direction is totally reflected to the coupling-out area, and the pupil can be effectively expanded for the output image, thereby expanding the view angle range and further meeting the user requirements.

The optical waveguide unit 2 further includes a first light shielding layer 22 disposed at one side of the optical waveguide 21 and a second light shielding layer 23 disposed at the other side of the optical waveguide 21, the first light shielding layer 22 being configured to absorb the light transmitted from the optical waveguide 21, and the second light shielding layer 23 being configured to absorb the light transmitted and/or reflected from the optical waveguide 21 and the solar light transmitted from the outside.

The first and second light-shielding

layers

22 and 23 have a gap with the optical waveguide 21 to absorb light transmitted or reflected from the optical waveguide 21 and prevent absorption of light inside the optical waveguide 21. The gap is not particularly limited and may be set according to actual needs.

The absorptivity of the first shading layer 22 and the second shading layer 23 to the visible light wave band is greater than 60%, that is, the first shading layer 22 and the second shading layer 23 can be made of a structure with absorptivity to the visible light wave band greater than 60% or a material with absorptivity to the visible light wave band greater than 60%, and specific materials and structures are not listed here one by one and can be selected according to actual needs.

If the light guide unit 2 is not provided with the first light shielding layer 22, a part of the image light transmitted through the light guide 21 is emitted through the light guide 21 even when the image light passes through the multiple light guides 21, and particularly, no matter whether the image light is vertically incident or obliquely incident to the coupling-in region, only a part of the image light is diffracted and transmitted through the light guide 21, and 0 th order diffracted light is emitted through the light guide 21. The partial image light rays are reflected or diffusely reflected by any surface with the reflection characteristic, and the reflected or diffusely reflected light rays are incident into the optical waveguide 21 again, so that stray light is introduced to influence the imaging quality. The optical waveguide unit 2 is provided with the first light shielding layer 22, so that the first light shielding layer 22 absorbs the image light emitted through the optical waveguide 21, and prevents the image light from being reflected or diffused and then being incident into the optical waveguide 21 again, thereby reducing interference and improving imaging quality.

The first light shielding layer 22 covers the projection area of the coupling-in area on the surface of the optical waveguide 21 in the projection area on the surface of the optical waveguide 21, and the first light shielding layer 22 is disposed apart from the projection area of the coupling-out area on the surface of the optical waveguide 21 in the projection area on the surface of the optical waveguide 21, thereby absorbing the light transmitted from the surface of the optical waveguide 21 to the maximum extent. That is, the maximum range covered by the first light shielding layer 22 in the projection region of the surface of the optical waveguide 21 is the area other than the projection region of the coupling-out region on the surface of the optical waveguide 21, and the minimum range is the projection region of the coupling-in region on the surface of the optical waveguide 21.

If the optical waveguide unit 2 is not provided with the second light shielding layer 23, even if the image light transmitted in the optical waveguide 21 passes through the multiple optical waveguides 21, the image light will be transmitted out at the side of the coupling-out region opposite to the reflection unit 3 and the external solar light will also enter the optical waveguide 21 and be transmitted out from the side of the coupling-out region 213 opposite to the reflection unit 3 after passing through the reflection unit 3, that is, the solar light will also flow backwards and be reversely transmitted in the optical waveguide 21, which causes the temperature rise and damage of the key device. Meanwhile, when the image light enters the optical waveguide 21, part of the light is reflected by the surface of the optical waveguide 21, the light is reflected or diffusely reflected by any surface with the reflection characteristic, and the reflected or diffusely reflected light enters the optical waveguide 21 again to introduce stray light, thereby affecting the imaging quality. And the optical waveguide unit 2 is provided with the second light shielding layer 23, the second light shielding layer 23 absorbs the light rays, and the light rays are prevented from being incident into the optical waveguide 21 again or being reversely conducted after being reflected or diffused, so that the influence is weakened, and the imaging quality is improved.

The second light shielding layer 23 covers the projection area of the coupling-out area on the surface of the optical waveguide 21 in the projection area on the surface of the optical waveguide 21, and the second light shielding layer 23 is disposed apart from the projection area of the image unit 1 on the surface of the optical waveguide 21 in the projection area on the surface of the optical waveguide 21, thereby absorbing the light transmitted or/and reflected from the surface of the optical waveguide 21 to the maximum. That is, the maximum range covered by the projection region of the second light shielding layer 23 on the surface of the light guide 21 is an area other than the projection region of the image unit 1 on the surface of the light guide 21, and the minimum range is the projection region of the coupling-out region on the surface of the light guide 21.

By setting the size of the grating structures of the coupling-in area and the coupling-out area, the distance between the grating structures and the specific structure of the grating, the thickness size of the optical waveguide 21 and the positions and the sizes of the first light shielding layer 22 and the second light shielding layer 23, image light can be diffracted and coupled in through the coupling-in area, the light is diffracted and transmitted to the coupling-out area through the optical waveguide 21, the light transmitted and reflected out of the surface of the optical waveguide 21 is absorbed by the first light shielding layer 22 or the second light shielding layer 23, is emitted from the coupling-out area and irradiates to the reflection unit 3, the light is reflected to human eyes by the reflection unit 3, a virtual image of the image is formed in front of the human eyes, and the imaging quality is improved.

The reflecting unit 3 comprises a transparent member 31 having a reflecting function and a multispectral reflecting layer 32 disposed on the transparent member 31, wherein the transparent member 31 comprises at least two transparent plates disposed in a stacked manner, that is, the image light is irradiated to the transparent member 31, and the transparent member 31 reflects the image light at least twice. The transparent member 31 includes a first transparent plate 311 disposed adjacent to the optical waveguide unit 2 and a second transparent plate 312 disposed to be stacked with the first transparent plate 311. The first transparent plate 311 and the second transparent plate 312 may have a curved surface structure or a planar structure, and are not particularly limited herein. In this embodiment, the transparent member 31 is a double-layer windshield, and the first transparent plate 311 and the second transparent plate 312 are both windshields, but the utility model is not limited thereto, and the transparent member 31 may have other structures, which are not listed here.

As shown in fig. 6 and 8, the multispectral reflective layer 32 highly reflects the narrow bandwidth at the red, green and blue main wavelength ranges, so that the light with the most wide bandwidth is passed, and the total light is prevented from being reflected, thereby generating a mirror effect and affecting safety.

Referring to fig. 2, in the AR-HUD scheme of the prior art, the image light emitted through the optical waveguide unit is incident on the reflection unit 03, the reflection unit 03 is a windshield 03, and the windshield has a high transmittance characteristic and a low reflectance, so that most of the image light is emitted through the windshield, and less of the image light is reflected by the windshield and received by human eyes, thereby greatly reducing the light utilization efficiency.

Referring to fig. 3, the windshield 03 is generally a double-layer windshield, and has two front surfaces, and image light emitted through the optical waveguide unit enters the double-layer windshield, is first reflected by the first front surface 031, and a portion of the light passes through the first front surface 031 and enters the second front surface 032, and is reflected again by the second front surface 032, and the light reflected twice is received by human eyes, so that a ghost image effect appears in a remote virtual image.

Referring to fig. 4, the multispectral reflective layer 32 is provided to improve the display efficiency, and the image light emitted through the optical waveguide unit 2 enters the reflective unit 3 and is reflected by the multispectral reflective layer 32 on the surface of the reflective unit 3, and since the multispectral reflective layer 32 has high reflection efficiency, most of the light is reflected to the human eye, and the light utilization efficiency is obviously improved.

Referring to fig. 5, the multispectral reflective layer 32 is disposed on the first transparent plate 311 near the optical waveguide unit 2, so that most of the image light is reflected on the first transparent plate 311, and less image light is transmitted through the first transparent plate to the second transparent plate 312, i.e., the first reflection of the transparent member 31 is enhanced, and the second reflection of the transparent member 31 is weakened or even eliminated, so that the main image light received by human eyes is only the light reflected by the first transparent plate, and the reflected light of the second transparent plate can be ignored, thereby effectively eliminating the ghost phenomenon. The specific reflection efficiency of the multispectral reflective layer 32 depends on the acceptable range of ratios of the reflection efficiencies of the first and second light-transmitting plates.

The multispectral reflective layer includes at least one low index layer and at least one high index layer, which may be expressed as (LH) ^ m, where L is the low index layer, H is the high index layer, and m is the number of lamination cycles.

Wherein the thickness range of the low refractive index layer is 0-300 nm, the thickness range of the high refractive index layer is 0-100 nm, and the number m of the laminating cycles is 2-50. The thickness range of the first low-refractive-index layer close to the first transparent plate is larger than 0, namely, the first low-refractive-index layer close to the first transparent plate in the multispectral reflecting layer is a low-refractive-index layer.

The low refractive index layer has a refractive index in the range of 1.3 to 1.78. The high refractive index layer has a refractive index in the range of 1.8 to 2.9, and the difference between the refractive index of the high refractive index layer and the refractive index of the low refractive index layer is at least 0.1.

The material of the low refractive index layer is one or more of silicon oxide, aluminum oxide and magnesium fluoride; the material of the high refractive index layer is one or more of titanium oxide, iron oxide, niobium oxide, tantalum oxide, zirconium oxide, chromium oxide, cerium oxide, and cobalt oxide. The low refractive index layer and the high refractive index layer may be made of other materials, which are not listed here.

In addition, a matching layer is arranged between the multispectral reflecting layer and the first transparent plate, and the refractive index of the matching layer is 2.0-2.9. The material of the matching layer is typically silicon dioxide.

The multispectral reflecting layer has 70-100% of reflectivity for light with a wave band of 440-460 nm, 70-100% of reflectivity for light with a wave band of 515-535 nm and 70-100% of reflectivity for light with a wave band of 610-630 nm.

The above-described reflective unit is further described with reference to specific embodiments below.

Example one

The reflection unit can be expressed as: SM | (LH) ^ m |,where S is the transparent member, i.e. the windscreen, M is the matching layer, which is a high refractive index material TiO₂L is a low refractive index material SiO₂H is high refractive index material TiO₂And m is the number of lamination cycles, and the thicknesses of the respective layers are shown in table 1 below.

TABLE 1 materials and thicknesses of the matching layer, the low refractive index layer, and the high refractive index layer in example one

Referring to fig. 6, in the reflection efficiency curve diagram of the multispectral reflection layer obtained in the present embodiment in the visible light band, the reflectivity of the multispectral reflection layer for the light with the wavelength of 430-460 nm is greater than 70%, the reflectivity of the multispectral reflection layer for the light with the wavelength of 520-530 nm is greater than 70%, and the reflectivity of the multispectral reflection layer for the light with the wavelength of 580-635 nm is greater than 70%.

The present application also provides a method for preparing the above-described reflective element, the method comprising:

s11: providing a transfer layer, and manufacturing a matching layer on the transfer layer;

s12: preparing a low-refractive-index layer on the matching layer, and preparing the low-refractive-index layer or the high-refractive-index layer for multiple times to form a multispectral reflecting layer;

s13: and attaching the transfer layer to the first transparent plate to obtain the reflecting unit.

The transfer layer is used as a carrier in the manufacturing of the multispectral reflecting layer and is used for transferring the multispectral reflecting layer to the windshield, and the material of the transfer layer is flexible acrylic, resin, plastic and the like, which are not listed.

The matching layer, the low refractive index layer, and the high refractive index layer may be prepared by Physical Vapor Deposition (PVD), but are not limited thereto and may be prepared by other methods.

The specific thicknesses, materials used, and lamination of the low refractive index layer and the high refractive index layer may be set according to actual needs.

The multispectral reflective layer can also be in other configurations, including a substrate layer and a microstructured layer formed on the substrate layer.

The microstructure layer comprises a plurality of microstructures which are repeatedly arranged, each microstructure comprises at least three microstructure units, and the width of each microstructure unit is different. The microstructure unit comprises a protrusion and a groove arranged adjacent to the protrusion, the width range of the protrusion is 100-400 nm, the height range of the protrusion is 50-300 nm, and the width range of the groove is 50-300 nm.

The refractive index of the substrate layer and the microstructure layer is 1.4-1.7, and the material of the substrate layer and the microstructure layer is any one of flexible acrylic, resin and plastic, but not limited thereto. And the transmissivity of the base layer to visible light wave bands is more than 80%.

Example two

Referring to fig. 7, the base layer 321 of the multispectral reflective layer 32 is made of silicon oxide, and the microstructure in the microstructure layer includes three microstructure units, namely a first microstructure unit, a second microstructure unit and a third microstructure unit, wherein the first microstructure unit includes a first protrusion 322 and a first groove 323, the second microstructure unit includes a second protrusion 324 and a second groove 325, and the third microstructure unit includes a third protrusion 326 and a third groove 327. The width p1 of the first protrusion 322 is 0.2 μm, the width p2 of the second protrusion 324 is 0.25 μm, the width p3 of the third protrusion 326 is 0.3 μm, the width f1 of the first groove 323 is 0.1 μm, the width f2 of the second groove 325 is 0.15 μm, the width f3 of the third groove 327 is 0.25 μm, and the heights of the first protrusion 322, the second protrusion 324, and the third protrusion 326 are 0.2 μm.

Referring to fig. 8, in the graph of the reflection efficiency of the multispectral reflective layer obtained in the present embodiment in the visible light band, the reflectance for the light with a wavelength of 450nm is greater than 60%, the reflectance for the light with a wavelength of 540nm is greater than 60%, and the reflectance for the light with a wavelength of 640nm is greater than 20%.

The present application also provides a method for preparing the reflective element shown above, the method comprising:

s21: providing a substrate layer, and spin-coating photoresist on the substrate layer;

s22: preparing a pattern of the microstructure layer on the photoresist;

s23: transferring the pattern of the microstructure layer to a substrate layer to form a multispectral reflecting layer;

s24: providing a transfer layer, and transferring the multispectral reflecting layer to the transfer layer;

s25: and attaching the transfer layer to the first transparent plate to obtain the reflecting unit.

The preparation method of the pattern of the microstructure layer is a photoetching method or an exposure method, and the method for transferring the pattern of the microstructure layer to the substrate layer is an ion etching method or a physical and chemical reaction method. The material of the transfer layer is any one of flexible acrylic, resin and plastic, but is not limited thereto, and is not listed here. The method of transferring the multispectral reflective layer to the transfer layer may be embossing, i.e. fixing the multispectral reflective layer to the transfer layer, thereby facilitating subsequent use.

The present application further provides a vehicle including an augmented reality heads-up display device as shown above, forming a virtual image in front of a windshield. The vehicle may be a bicycle, an electric vehicle, and the like, for example, a pure electric vehicle, an extended range electric vehicle, a hybrid electric vehicle, a fuel cell vehicle, a new energy vehicle, and the like, which is not particularly limited. The multispectral wave band reflecting layer is beneficial to improving the display efficiency and improving the universality of the design of the windshield. The multispectral waveband reflecting layer enhances the first reflection of the windshield, weakens or even eliminates the second reflection of the windshield, and therefore the double image phenomenon can be effectively eliminated.

In summary, the augmented reality head-up display device of the present invention is provided with the multispectral reflective layer having a high reflectivity with a certain bandwidth for red, green and blue multiband light on the first transparent plate near the optical waveguide unit, so as to reflect image light, so that less image light is incident to other transparent plates through the first transparent plate, thereby effectively eliminating the ghost phenomenon, and improving the quality and efficiency of the displayed image.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the utility model. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. The augmented reality head-up display device is characterized by comprising an image unit, an optical waveguide unit and a reflection unit, wherein the reflection unit comprises a transparent piece with a reflection function and a multispectral reflection layer arranged on the transparent piece, the transparent piece comprises at least two transparent plates which are arranged in a stacked mode, and the multispectral reflection layer is arranged on a first transparent plate close to the optical waveguide unit.

2. The augmented reality heads-up display device of claim 1 wherein the multi-spectral reflective layer comprises at least one low index layer and at least one high index layer, the multi-spectral reflective layer being expressible as (LH) m, wherein L is the low index layer, H is the high index layer, m is the number of stacking cycles, and the refractive index of the high index layer and the refractive index of the low index layer differ by at least 0.1.

3. The augmented reality heads-up display device of claim 2 wherein the low refractive index layer has a thickness in a range of 0 to 300 nm; the thickness range of the high-refractive-index layer is 0-100 nm; the number m of the laminating cycles is 2-50, and the thickness range of the first low-refractive-index layer close to the first transparent plate is larger than 0.

4. The augmented reality head-up display device of claim 2, wherein the low refractive index layer has a refractive index in a range of 1.3 to 1.78; the refractive index range of the high refractive index layer is 1.8-2.9.

5. The augmented reality head-up display device of claim 2, wherein the low refractive index layer is made of any one of silicon oxide, aluminum oxide, and magnesium fluoride; the material of the high refractive index layer is any one of titanium oxide, iron oxide, niobium oxide, tantalum oxide, zirconium oxide, chromium oxide, cerium oxide and cobalt oxide.

6. The augmented reality head-up display device of claim 2 wherein a matching layer is further disposed between the multispectral reflective layer and the first transparent plate, the matching layer having a refractive index of 2.0 to 2.9.

7. The augmented reality head-up display device of claim 1, wherein the multispectral reflective layer comprises a substrate layer and a microstructure layer formed on the substrate layer, the microstructure layer comprises a plurality of microstructures repeatedly arranged, each microstructure comprises at least three microstructure units, the width of each microstructure unit is different, each microstructure unit comprises a protrusion and a groove arranged adjacent to the protrusion, the width of each protrusion is 100-400 nm, the height of each protrusion is 50-300 nm, and the width of each groove is 50-300 nm.

8. The augmented reality head-up display device of claim 7, wherein the refractive index of the substrate layer and the micro-structural layer is 1.4-1.7, and the substrate layer and the micro-structural layer are made of any one of flexible acrylic, resin and plastic.

9. The augmented reality heads-up display device of claim 1 wherein the transparent member is a double windshield.

10. The augmented reality heads-up display device of claim 1 wherein the optical waveguide unit comprises at least one optical waveguide, and a first light shielding layer disposed on one side of the optical waveguide and a second light shielding layer disposed on the other side of the optical waveguide.

11. A vehicle comprising an augmented reality heads-up display device of any one of claims 1-10.