Display device and vehicle

Abstract

The invention discloses a display device and a vehicle, and belongs to the technical field of display. The display device comprises a transmission light path, the transmission light path is used for transmitting a display image output by a display assembly to a display medium, at least one blazed grating is arranged in the transmission light path, and the blazed grating is used for carrying out image amplification processing on the display image output by the display assembly. The blazed grating is characterized in that the incident direction is strictly screened, only a small number of incident light rays which strictly conform to a grating diffraction equation in the direction can be reversely transmitted to the display assembly, and incident sunlight which does not conform to the grating diffraction equation is diffracted to other directions, so that the sunlight can be prevented from flowing backwards; the service life of the display assembly is prevented from being shortened due to sunlight backflow.

Description

Technical Field

[0001] The present application belongs to the field of vehicle technology, and in particular, relates to a display device and a vehicle. Background Art

[0002] In a vehicle, a head-up display device can transmit information such as assisted driving to the front of the driver, for example, it can be projected onto the front windshield to facilitate the driver's driving operations. The head-up display device may include a display component and a transmission optical path. The display component can output a head-up display image, and the above image can be output to the front windshield through the transmission optical path. In the related art, a curved reflector is mainly set on the transmission optical path to amplify and transmit the head-up display image through the curved reflector. However, the reflection optical path of the curved reflector is reversible, so there will be a problem of sunlight backflow. Summary of the invention

[0003] The present application aims to at least solve the technical problems existing in the prior art. To this end, the present application provides a display device and a vehicle, which can solve the problem of sunlight backflow existing in the prior art.

[0004] In a first aspect, the present application provides a display device, comprising:

[0005] The transmission optical path is used to transmit the display image output by the display component to the display medium. At least one blazed grating is arranged in the transmission optical path. The blazed grating is used to perform image magnification processing on the display image output by the display component.

[0006] In some embodiments, a first blazed grating and a second blazed grating opposite to each other are arranged on the transmission light path;

[0007] The first blazed grating is used to perform a first image magnification process on the display image output by the display component and then project it onto the second blazed grating;

[0008] The second blazed grating is used to perform a second image magnification process on the display image after the first image magnification process and then project the image onto a display medium.

[0009] In some embodiments, a relative transmission grating and a third blazed grating are arranged on the transmission light path;

[0010] The transmission grating is used to project the display image output by the display component onto the third blazed grating after performing a first image amplification process;

[0011] The third blazed grating is used to perform a second image magnification process on the display image after the first image magnification process, and then project the image onto the display medium.

[0012] In some embodiments, the wavelength range used by the display component when outputting the display image is a first preset wavelength range, and the blazing wavelength of the blazed grating is within the first preset wavelength range. In some embodiments, the blazing wavelength of the blazed grating is the central wavelength of the first preset wavelength range.

[0013] In some embodiments, the blazed grating includes a substrate, and adjacently distributed grating groove surfaces are formed on the substrate, wherein the grating groove surfaces serve as a reflection plane;

[0014] In some embodiments, a reflective film is formed on the grating groove surface.

[0015] In some embodiments, the substrate is at least one of a plastic glass substrate, a metal substrate, and a resin substrate.

[0016] In some embodiments, the reflective film is formed on the grating groove surface by using nanoimprint technology.

[0017] In some embodiments, the adjacently distributed grating groove faces include at least two categories, and the blaze angles of the grating groove faces of different categories are different.

[0018] In some embodiments, the at least one grating groove surface of the same category constitutes a grating groove surface group, and grating groove surface groups of different categories are arranged in sequence at intervals.

[0019] In a second aspect, the present application provides a vehicle, comprising the above-mentioned display device and a front windshield, wherein the above-mentioned front windshield is used as a display medium of the display device.

[0020] The display device provided by the embodiment of the present application, wherein at least one blazed grating is arranged in the transmission light path of the display device, and the blazed grating is used to perform image magnification processing on the display image output by the display component. The characteristic of the blazed grating is that it has strict screening for the incident direction, and only a few directions of incident light that strictly conform to the grating diffraction equation will be transmitted back to the display component, while the incident sunlight that does not conform to the grating diffraction equation will be diffracted to other directions, thereby preventing sunlight from flowing back and avoiding the shortening of the service life of the display component due to sunlight flowing back. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The above aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0022] Figure 1 A schematic diagram of the structure of a display device provided in an embodiment of the present application;

[0023] Figure 2 A diffraction diagram of a blazed grating provided in an embodiment of the present application;

[0024] Figure 3 A schematic diagram of the structure of another display device provided in an embodiment of the present application;

[0025] Figure 4 A schematic diagram of the structure of another display device provided in an embodiment of the present application;

[0026] Figure 5 A schematic diagram of the working principle of a blazed grating provided in an embodiment of the present application;

[0027] Figure 6 A schematic diagram of a blazed grating structure provided in an embodiment of the present application;

[0028] Figure 7 A schematic diagram of the structure of another blazed grating provided in an embodiment of the present application;

[0029] Figure 8 A schematic diagram of imaging of a display device provided in an embodiment of the present application;

[0030] Fig. 9 A schematic diagram of the structure of another blazed grating provided in an embodiment of the present application;

[0031] Fig.10 A schematic structural diagram of a vehicle provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0033] The terms "first", "second", etc. in the specification and claims of this application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0034] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0035] Reference is made herein to the figures as idealized exemplary embodiments and, thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of exemplary embodiments.

[0036] Examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and should not be construed as limiting the present application. The optical path of the present application is described in detail below, and the description of the optical path is shown in the accompanying drawings, where the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions.

[0037] As described in the prior art, there is a problem of sunlight backflow in existing display light devices, which can shorten the service life of the display components that output the head-up display image or even burn them out due to the heat generated by the convergence of light; and the existing display devices need to present the image in a pseudo-stereoscopic effect by using the method of "far away is big and near is small", which can easily cause dizziness. Based on the above technical defects, the embodiments of the present application provide a display device based on blazed grating imaging.

[0038] Figure 1 is a schematic diagram of the structure of a display device in an embodiment of the present application, such as Figure 1 As shown, the display device 10 includes a transmission optical path 12, which is used to transmit the display image output by the display component 11 to the display medium 13, and at least one blazed grating 120 is arranged in the transmission optical path 12, and the blazed grating 120 is used to perform image magnification processing on the display image output by the display component 11.

[0039] In the embodiment of the present application, the display component 11 is used to output a display image, which may also be referred to as a picture generating unit (Picture Generating Unit, PGU for short), which is responsible for generating and outputting a display image, which is transmitted and amplified in the transmission optical path 12 and finally projected onto the display medium 13. For example, in a vehicle display system, the display image output by the display component 11 may be key driving information such as vehicle speed, navigation prompts, and lane information, which is intended to help the driver obtain information without taking his eyes off the road, thereby improving driving safety.

[0040] At least one blazed grating 120 is arranged in the transmission light path 12 to achieve amplification of the displayed image.

[0041] The above-mentioned blazed grating 120 is a diffraction grating structure that can produce maximum diffraction efficiency at a certain diffraction level. The blazed grating 120 can also be called a plane reflection grating. The relationship between the diffraction order of the diffraction grating and the image magnification can be understood through the grating equation, that is, dsinθ=mλ, where d is the grating constant, θ is the diffraction angle, that is, the angle between the diffracted light and the surface normal, m is the diffraction order, and λ is the wavelength of the light. For incident light of a certain wavelength, by changing the incident angle or grating parameters, the diffraction angle of the diffracted light of a certain diffraction level can be controlled, that is, the diffraction direction of the light can be controlled, thereby achieving image magnification.

[0042] In the embodiment of the present application, the blazed grating 120 is a plane reflection grating. The specific diffraction principle can be referred to Figure 2 shown. Figure 2 A diffraction diagram of a blazed grating provided in an embodiment of the present application, such as Figure 2 As shown, when a beam of parallel light passes through the blazed grating 120, the image is magnified due to the diffraction of the light.

[0043] In related technologies, the large peak-to-valley values ​​of the free-form surface reflectors will cause distortion of the displayed image, directly affecting the driver's visual experience and even causing dizziness, seriously endangering driving safety. However, under the current cost control strategy, it is difficult to further reduce the peak-to-valley values ​​of the reflections due to the limitations of machining accuracy. In addition, most of the current free-form surface reflectors use the optical principle of concave mirror magnification projection. Inevitably, the optical focusing characteristics of the concave mirror cause the sunlight to flow back and focus on the PGU. The convergence of light causes the PGU to overheat or even burn. As the imaging distance increases and the image magnification increases, the problem of sunlight backflow becomes more obvious. Even if measures such as filtering infrared waves are used to alleviate the problem, the degree of relief is very limited, and other costs will also increase.

[0044] In contrast, in the display device 10 provided in the embodiment of the present application, at least one blazed grating 120 is provided in the transmission optical path 12 of the display device 10, and the blazed grating 120 is used to perform image magnification processing on the display image output by the display component 11. The characteristic of the blazed grating is that it has strict screening for the incident direction, and only a few incident light rays that strictly conform to the grating diffraction equation in a few directions will be transmitted back to the display component, while the incident sunlight that does not conform to the grating diffraction equation will be diffracted to other directions, thereby preventing sunlight from flowing back and preventing the display component from having its service life shortened due to sunlight flowing back.

[0045] In the embodiment of the present application, the transmission optical path 12 includes at least one blazed grating 120 to achieve the above technical effect. In some embodiments, two blazed gratings may be provided, such as Figure 3 As shown, Figure 3 A schematic diagram of the structure of another display device provided in an embodiment of the present application, wherein a first blazed grating and a second blazed grating are provided; a transmission grating and a blazed grating may be provided, for example Figure 4 As shown, Figure 4 A structural diagram of another display device provided in an embodiment of the present application includes a transmission grating and a third blazed grating, or in some cases, a blazed grating and a curved reflector may also be provided.

[0046] like Figure 5 As shown, Figure 5 A schematic diagram of the working principle of a blazed grating provided in an embodiment of the present application, wherein the surface of the blazed grating is engraved to form a series of serrated groove surfaces, which can be called grating groove surfaces. These grating groove surfaces can reflect light, and the angle γ between the grating groove surfaces and the grating plane is also called the blaze angle.

[0047] The blazed grating can concentrate most of the incident light on a specific diffraction order. Correspondingly, the diffracted light of this diffraction order has a corresponding diffraction angle θ. Figure 5 Where N represents the grating surface normal, n represents the grating groove surface normal, A represents the incident light direction, and B represents the direction of the diffracted light with maximum intensity.

[0048] The central direction of the diffraction maximum of the blazed grating 120 is determined by the direction of the normal line n of the grating groove surface, and the main maximums of each level of interference between the grating groove surfaces are determined by the grating equation. To make the central maximum coincide with the main maximum of the interference m level, it is necessary to satisfy 2dsinθ0cosα=mλ b , where d is the grating period, angle θ0 is the angle between the grating surface normal N of the blazed grating 120 and the groove surface normal n, which is equal to the blaze angle γ of the blazed grating 120, angle α is the angle between the incident light A and the grating groove surface normal n, m is the diffraction order, λ b is the wavelength of incident light. Figure 5 The angle θ in represents the angle between the maximum intensity diffracted light B and the normal line n of the groove surface, that is, the diffraction angle of the maximum intensity diffracted light. When m=1, it represents the positive first-order diffraction.

[0049] For incident light, the main maximum of diffracted light can be transferred to the non-zero-order interference maximum by adjusting the grating equation. In practice, 80% to 90% of the light energy is concentrated on the first-order spectrum of the incident light, which fully meets the requirements of augmented reality display for light energy utilization.

[0050] By adopting the above-mentioned blazed grating, the propagation direction of light can be changed, which is beneficial to the folding of the light path, and by changing the blazed angle of the blazed grating, the direction of the diffracted light can be changed. The blazed grating is used to replace the free-form surface reflector in the related technology to realize the amplification and transmission of the display image, which is low in cost, and only a few directions of incident light that strictly conform to the grating diffraction equation will be transmitted back to the display component, while the incident sunlight that does not conform to the grating diffraction equation will be diffracted to other directions, thereby preventing sunlight backflow and avoiding the display component from having its service life shortened due to sunlight backflow.

[0051] In some embodiments, Figure 3 As shown, the transmission optical path 12 is provided with a relative first blazed grating 121 and a second blazed grating 122, wherein the first blazed grating 121 is used to perform a first image magnification processing on the display image output by the display component 11 and then project it onto the second blazed grating 122, and the second blazed grating 122 is used to perform a second image magnification processing on the display image that has undergone the first image magnification processing and then project it onto the display medium 13.

[0052] By providing two blazed gratings 120, namely, a first blazed grating 121 and a second blazed grating 122, the optical path can be folded in a limited space, so that the display device 10 is smaller. In addition, after two magnification projections, not only the direction of image projection display can be changed, but also the multiplication of the two magnifications enables the image finally projected onto the display medium 13 to achieve a larger magnification at a smaller spatial distance, which is beneficial to the application of the display device 10 in relevant scenarios. Moreover, by combining two blazed gratings, the size and position of the image can be controlled more accurately, which is beneficial to eliminate the image distortion caused by the display medium 13 and improve the image quality. By adjusting the angle and position between the first blazed grating 121 and the second blazed grating 122, the coverage of the displayed image can be adjusted.

[0053] In some embodiments, Figure 4As shown, a transmission grating 123 and a third blazed grating 124 are provided on the transmission optical path 12, wherein the transmission grating 123 is used to perform a first image magnification processing on the display image output by the display component 11 and then project it onto the third blazed grating 124; the third blazed grating 124 is used to perform a second image magnification processing on the display image after the first image magnification processing and then project it onto the display medium.

[0054] The transmission grating 123 is also a diffraction grating structure, which can realize the diffraction of the transmitted light by forming a plurality of equally spaced slits on the grating plane, and the relationship between the diffraction order of the diffraction grating and the image magnification can be understood through the grating equation, that is, dsinθ=mλ, where d is the grating constant, which is the spacing between the slits in the transmission grating, θ is the diffraction angle, that is, the angle between the diffracted light and the surface normal, m is the diffraction order, and λ is the wavelength of the incident light. For incident light of a certain wavelength, by changing the incident angle or grating parameters, the diffraction angle of the diffracted light of a certain diffraction order can be controlled, that is, the diffraction direction of the light can be controlled, thereby realizing image magnification, and the third diffraction grating 124, which has the same working principle as the first blazed grating 121 and the second blazed grating 122, can be referred to. Figure 5 In some embodiments, as shown in Figure 1 , Figure 3 or Figure 4 As shown, the wavelength range used by the display component 11 when outputting the display image is the first preset wavelength range, and the blazing wavelength of the blazed grating 120 (including the first blazed grating 121, the second blazed grating 122 and the third blazed grating 124) is within the above-mentioned first preset wavelength range.

[0055] Specifically, according to the grating diffraction equation, the diffraction intensity is related to the wavelength of the incident light, and the blaze wavelength refers to the wavelength of maximum diffraction corresponding to the blaze angle in the blazed grating under certain incident angles and diffraction angles. The blaze wavelength is determined by the blaze angle. That is, in an application scenario with a certain incident angle and diffraction angle, the diffraction efficiency of the blazed grating can reach the maximum at the blaze wavelength.

[0056] Based on the working principle of the aforementioned blazed grating 120, in the display device 10 provided in the embodiment of the present application, the diffraction direction of the light of the relevant wavelength is precisely controlled by the grating equation to achieve image magnification. It should be pointed out here that although the blazed grating 120 only produces maximum light intensity diffraction for the blazed wavelength in the same level spectrum, since the central maximum to minimum of the groove surface diffraction has a certain width, the spectrum lines within a certain wavelength range near the blazed wavelength also have considerable light intensity, so the blazed grating can be used for a certain wavelength range, and the light emitted by the display component 11 of the display device 10 can be used for imaging after simple filtering. For example, if the blazed wavelength is 650nm, the above-mentioned first preset wavelength range can be a wavelength range including the above-mentioned blazed wavelength.

[0057] In some embodiments, the blazed wavelength of the blazed grating 120 (including the first blazed grating 121, the second blazed grating 122, and the third blazed grating 124) is the central wavelength of the first preset wavelength range. For example, the blazed wavelength is 550nm, and the first preset wavelength range is 500nm to 600nm. Or for example, the blazed wavelength is 640nm, and the first preset wavelength range is 610nm to 690nm. Within the blazed wavelength and its vicinity, the diffraction efficiency of the blazed grating can reach a relatively large value, so that most of the light energy can be concentrated on a certain diffraction order, thereby improving the brightness and contrast of the image, which helps to enhance the image magnification effect. The improvement of the diffraction efficiency also means that the signal-to-noise ratio of the image increases, thereby improving the resolution.

[0058] In some embodiments, Figure 6 As shown, Figure 6 A schematic diagram of a blazed grating structure provided in an embodiment of the present application is shown in FIG. Figure 6 As shown, the blazed grating 120 includes a substrate 21, and adjacently distributed grating groove surfaces 22 are formed on the substrate 21. The grating groove surfaces 22 are used as reflection planes to form a planar reflection grating. The grating groove surfaces 22 can form reflection planes in various ways. For example, when the substrate 21 is made of metal material, the grating groove surfaces 22 can be smoothed to form reflection planes. In some cases, a reflection film 23 can also be formed on the grating groove surfaces 22.

[0059] The grating groove surface 22 is a series of sawtooth groove surfaces engraved on the substrate 21, such as Figure 5 As shown, when the incident light A irradiates the grating groove surface 22, under the action of the reflective film 23, each grating groove surface 22 acts as a secondary wave source to emit spherical waves, and these spherical waves interfere with each other in space to finally achieve the purpose of the blazed grating design. The reflective film 23 can improve the reflection efficiency of light, thereby improving the brightness and contrast of the image.

[0060] In some embodiments, the substrate 21 is at least one of a plastic glass substrate, a metal substrate, and a resin substrate. The plastic glass substrate has high plasticity and can be manufactured into various shapes by heating and molding, which is low in cost, and can be mass-produced by an automated injection molding process, further reducing costs. In addition, the plastic glass substrate has high strength, is not easily deformed, has good optical memory performance under temperature changes, and has good adaptability to changes in temperature and humidity.

[0061] In the related art, the free-form surface reflector is usually formed by coating a metal reflective film on a plastic substrate to achieve image light reflection, which requires a lengthy manufacturing process for the processing and preparation of the free-form surface reflector, and the display device 10 usually needs to work at a relatively high temperature, which makes the plastic substrate very easy to deform, thereby causing image distortion and affecting the display effect. In order to control the deformation, there is also a method of coating a metal film on a metal substrate. Although the strength of metal is much greater than that of plastic and deformation can be controlled, this will increase the cost.

[0062] In comparison, the blazed grating 120 uses a plastic glass substrate, which is less expensive and less prone to distortion, and can also effectively control image propagation to ensure image display effects.

[0063] In some embodiments, Figure 6 As shown, the reflective film 23 is formed on the grating groove surface 22 by using the nano-imprinting technology. The nano-imprinting process has the characteristics of being mature, high in precision, low in cost, and not prone to distortion, and can overcome the related problems existing in the above-mentioned related technologies.

[0064] The material of the reflective film 23 may include aluminum, which has good reflective properties and high stability, so that light utilization is high, which is beneficial to improving image display brightness.

[0065] In addition, nanoimprinting technology can achieve a higher resolution, and the imprinting accuracy can be controlled within ±5nm. The production efficiency is higher by transferring patterns through nanoimprinting technology, and the manufacturing cost is lower because no complex optical path system or light source is required during the process. When making the blazed grating 120 by nanoimprinting, it is only necessary to process the template, that is, the template matches the required grating groove surface 22, and then large-scale imprinting can be carried out. The preparation is relatively simple, and the template can be reused, which is suitable for large-scale production. The blazed grating 120 generated by nanoimprinting technology can effectively ensure the propagation of light, thereby forming a clearer display image.

[0066] In some embodiments, Figure 7 As shown, Figure 7A schematic diagram of the structure of another blazed grating provided in an embodiment of the present application, on the substrate 21 of the blazed grating 120, adjacently distributed grating groove faces 22 include at least two categories of grating groove faces, and different categories of grating groove faces 22 have different angles with the grating face, that is, different categories of grating groove faces 22 have different blazed angles.

[0067] For example, the grating groove face 221 is a grating groove face of one category, and its blaze angle is γ1, the grating groove face 222 is another category, and its blaze angle is γ2, etc. A plurality of grating groove faces 22 with different blaze angles are periodically distributed on the substrate 21. According to the working principle of the blazed grating 120 described above, the diffraction angles of the maximum intensity diffracted light at different blaze angles are also different. Therefore, under the action of different blaze angles, the angle of the maximum intensity diffracted light of the same beam of light will shift during the propagation process.

[0068] like Figure 8 As shown, Figure 8 This is a schematic diagram of imaging of a display device provided in an embodiment of the present application. When the maximum intensity diffracted light at different diffraction angles is projected onto the display medium 13, the imaging distances of the diffracted light at different diffraction angles are different under the imaging effect of the display medium 13. For example, the imaging distance of the maximum intensity diffracted light corresponding to the grating groove surface 221 is A1, the imaging distance of the maximum intensity diffracted light corresponding to the grating groove surface 222 is A2, and so on.

[0069] Therefore, because the blazed grating 120 periodically distributes at least two types of grating groove surfaces 22, at least two imaging surfaces can be formed correspondingly at at least two imaging distances in the display image formed by the display medium 13. The image on each imaging surface is the display image output by the display component 11, which is projected after being amplified by the optical path 12 and the imaging effect of the display medium 13. In the perspective of the observer, the images at multiple imaging distances are stacked and combined, and finally present a three-dimensional display effect.

[0070] In related technologies, free-form mirrors can only form images at one virtual image distance. When the displayed image needs to be integrated with the real scene, it can only present a pseudo 3D effect through psychological cues such as "near is big and far is small". This makes it impossible to accurately calibrate the image, and it is inevitable that there will be problems such as visual convergence adjustment conflicts, which will cause the driver to feel tired. If you want to form images at multiple virtual image distances, you need to use extremely complex methods such as single optical machine dual optical path, dual optical machine dual optical path, etc.

[0071] In comparison, the implementation method provided by the embodiment of the present application is simpler and easier to implement. In the embodiment of the present application, multiple types of grating groove surfaces 22, that is, multiple grating groove surfaces 22 with different blazing angles are periodically distributed, so that the display medium 13 can eventually form multiple imaging surfaces. That is, by setting two or more grating periods on the blazed grating 120, and then according to the grating equation, the image light that should not be imaged on the same plane is projected on planes with different imaging distances, that is, the field of view angle of the image light imaging can be changed, thereby realizing multi-imaging plane imaging, and the display effect is better, so that the problems of visual convergence adjustment conflict can be avoided, and the fatigue of the viewers can be reduced.

[0072] In some embodiments, Fig. 9 As shown, Fig. 9 The schematic diagram of the structure of another blazed grating provided in the embodiment of the present application is that at least one grating groove surface 22 of the same type constitutes a grating groove surface group, and grating groove surface groups of different types are arranged in sequence. Figure 7 The arrangement of the grating groove surface 221 and the grating groove surface 222 at intervals periodically may also be as follows: Fig. 9 As shown, two grating groove faces 221 constitute one grating groove face group, two grating groove faces 222 constitute another grating groove face group, and then multiple different grating groove face groups are arranged periodically. Alternatively, one grating groove face 221 is one grating groove face group, two grating groove faces 222 are another grating groove face group, and multiple different grating groove face groups are arranged periodically, and so on.

[0073] Different types of grating groove surfaces 22 can adjust the diffraction angle of light, so that the image light is projected and imaged on imaging planes at different distances. A plurality of grating groove surfaces 22 of the same type constitute a grating groove surface group, and the light passing through the grating groove surface group can be projected and imaged on an imaging plane. The setting mode of periodically distributing a plurality of grating groove surface groups can increase the degree of variation of the diffraction angle of light in the optical path 12, which is conducive to imaging the image output by the display component 11 on different focal planes, and ultimately improves the 3D display effect of the image.

[0074] In a second aspect, the present application provides a vehicle, such as Fig.10 As shown, Fig.10 The vehicle 20 includes the display device 10 and a front windshield 201 , and the front windshield 201 is used as the display medium 13 of the display device 10 .

[0075] The display device 10 projects the display image output by the display component 11 onto the front windshield 201. Under the imaging effect of the front windshield 201, a virtual image of the corresponding display image is formed in the driver's field of vision. The virtual image is located at a certain position in front of the driver's field of vision, so that the driver feels that the information is just floating on the road. When the driver observes the display image information, he can still clearly see the road and scenery ahead, thereby ensuring driving safety. The display device 10 can also be called a head-up display device.

[0076] Furthermore, when the front windshield 201 is used as the display medium 13 of the display device 10, the vehicle 20 can also deeply integrate it with the Advanced Driver Assistance Systems (ADAS), and use sensors installed on the vehicle 20, such as cameras, radars, laser radars, and ultrasonic sensors, to collect environmental data inside and outside the vehicle in real time, identify objects, detect and classify them, provide information assistance, warnings, auxiliary control and other information, and project relevant content onto the front windshield 201. For example, forward warnings, traffic sign recognition, lane departure warnings, lane keeping assistance, steering prompts, blind spot detection, intersections and road names and other information are displayed in three-dimensional stereoscopic form within the driver's field of view. The vehicle 20 can deeply integrate the display image with the display environment, vividly and reasonably superimpose and display driving information in the driver's line area, and have an AR real-scene fit.

[0077] Understandably, Fig.10 Only the structure of the front windshield of the vehicle is shown, and the structure of other parts of the vehicle is not shown. The technical solution of this embodiment can be applied to various types of vehicles so as to have corresponding structures.

[0078] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that a person skilled in the art can think of within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A display device, characterized in that: include: The transmission optical path is used to transmit the display image output by the display component to the display medium. At least one blazed grating is arranged in the transmission optical path. The blazed grating is used to perform image magnification processing on the display image output by the display component.

2. The display device according to claim 1, characterized in that The transmission light path is provided with a first blazed grating and a second blazed grating opposite to each other; The first blazed grating is used to perform a first image magnification process on the display image output by the display component and then project the image onto the second blazed grating; The second blazed grating is used to project the first image magnification processing display image onto the display medium after performing a second image magnification processing on the display image.

3. The display device according to claim 1, characterized in that The transmission optical path is provided with a relative transmission grating and a third blazed grating; The transmission grating is used to perform a first image magnification process on the display image output by the display component and then project it onto the third blazed grating; The third blazed grating is used to project the displayed image after performing a second image magnification process on the displayed image after the first image magnification process onto the display medium.

4. The display device according to any one of claims 1 to 3, characterized in that: The wavelength range used by the display component when outputting a display image is a first preset wavelength range, and the blazing wavelength of the blazed grating is within the first preset wavelength range.

5. The display device according to claim 4, characterized in that: The blazing wavelength of the blazed grating is the central wavelength of the first preset wavelength range.

6. The display device according to any one of claims 1 to 3, characterized in that: The blazed grating comprises a substrate, on which adjacently distributed grating groove surfaces are formed, and the grating groove surfaces serve as reflection planes.

7. The display device according to claim 6, characterized in that: A reflective film is formed on the grating groove surface.

8. The display device according to claim 7, characterized in that: The substrate is at least one of a plastic glass substrate, a metal substrate, and a resin substrate.

9. The display device according to claim 7, characterized in that: The reflective film is formed on the grating groove surface by using nano-imprint technology.

10. The display device according to claim 7, characterized in that: The adjacently distributed grating groove surfaces include at least two categories, and the blaze angles of the grating groove surfaces of different categories are all different.

11. The display device according to claim 10, characterized in that: At least one grating groove surface of the same type constitutes a grating groove surface group, and grating groove surface groups of different types are arranged in sequence at intervals.

12. A vehicle, characterized in that: It comprises the display device according to any one of claims 1 to 11, and a front windshield, wherein the front windshield is used as a display medium of the display device.

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