Diffusion screen, display device and vehicle

Abstract

The invention provides a diffusion screen which can be applied to a projection device and a vehicle. The diffusion screen provided by the invention can realize direction matching of projection light and image light, can reduce the size of the display device, and improves the imaging quality of the display device. The first surface of the diffusion screen provided by the invention comprises the microstructure array, and the curvatures of the plurality of microstructures of the microstructure array in the first direction are different, so that the diffusion screen can change the direction of the emergent image light in the first direction.

Description

Technical Field

[0001] The embodiments of the present application relate to the fields of display technology and smart car driving technology, and more specifically, to a diffusion screen, a display device, and a vehicle. Background Art

[0002] Cars have become an indispensable means of transportation in people's daily lives. With the increase in the number of cars, the frequency of traffic accidents is also increasing. In order to improve driving safety, head up display (HUD), especially augmented reality head up display (AR-HUD) has become a hot research direction.

[0003] AR-HUD systems often use picture generation units (PGUs) that use display chips such as liquid crystal on silicon (LCOS) and digital micro-mirror devices (DMD), and are paired with a diffusion screen so that the image projected by the PGU generates a relay image on the diffusion screen, and the diffusion screen then becomes the display image source for the HUD system. In order to achieve high brightness, high efficiency, and good uniformity in optical display effects, it is necessary to match the direction of the main light of the PGU projection with the direction of the main light of the rear-end imaging as much as possible, that is, the angles of the light incident on the diffusion screen and the light exiting the diffusion screen are required to be as consistent as possible. However, due to the small space layout of the HUD system and the need to prevent sunlight from backflowing, the HUD system has design limitations, that is, it is difficult to perfectly match the direction of the main projection light with the direction of the light of the rear-end imaging. At present, the general solution is to add a field lens to the system and use the field lens to adjust the angle of the light, such as Figure 1 As shown. However, this solution has many disadvantages, such as the field lens is too large, there is a risk of stray light on the surface, additional anti-reflection treatment is required, and the clarity of the displayed image deteriorates. Therefore, how to improve the matching degree between the direction of the main projection light and the direction of the back-end image light and improve the performance of the HUD system is a problem that needs to be solved. Summary of the invention

[0004] The present application provides a diffusion screen, a display device and a vehicle. The diffusion screen provided in the present application can achieve directional matching between projection light and image light, and when used in a display device, can reduce the volume of the display device and improve the imaging quality of the display device.

[0005] In a first aspect, an embodiment of the present application provides a diffusion screen, wherein a first surface of the diffusion screen comprises a microstructure array, a plurality of microstructures of the microstructure array have different curvatures in a first direction, and the diffusion screen is used to change the direction of emitted image light in the first direction.

[0006] Based on the above scheme, the diffusion screen provided by the present application changes the direction of image light emission through the curvature of the surface microstructure. When the curvature of the microstructure is different, different microstructures can achieve different deflection effects on image light, thereby achieving control of the emitted image light at different microstructures, thereby improving the utilization rate of light energy. When the diffusion screen is used in a display device, it can not only achieve a diffusion effect, but also adjust the direction of the emitted image light to match the direction of the incident light, thereby avoiding the problems of excessive device volume, energy loss and stray light caused by introducing elements such as field lenses that adjust the direction of light in the light path, thereby achieving a display device with better imaging quality and more compact volume.

[0007] In combination with the first aspect, in some implementations of the first aspect, the multiple microstructures of the microstructure array have different curvatures in the second direction, and the diffusion screen is used to change the direction of the emitted image light in the second direction.

[0008] Based on the above solution, the diffuser provided by the present application can change the direction of the emitted image light in the first direction and the second direction, so that the diffuser provided by the present application can be applied to a variety of display devices, increasing the use scenarios of the diffuser. At the same time, since the diffuser can change the emission direction of the image light in multiple directions, the position layout of other components in the display device can also be made more flexible, thereby improving the flexibility of the display device design.

[0009] In combination with the first aspect, in certain implementations of the first aspect, the thicknesses of the plurality of microstructures of the microstructure array in the third direction are different.

[0010] In combination with the first aspect, in certain implementations of the first aspect, thicknesses of any two adjacent microstructures in the microstructure array are different.

[0011] By designing the thickness of any microstructure to be different, the diffraction effect caused by each microstructure can be reduced, thereby achieving the purpose of improving imaging quality.

[0012] In combination with the first aspect, in some implementations of the first aspect, two directions among the first direction, the second direction and the third direction are perpendicular to each other.

[0013] In combination with the first aspect, in some implementations of the first aspect, the microstructure array is a microlens array.

[0014] In combination with the first aspect, in some implementations of the first aspect, the surface shape of the plurality of microlenses of the microlens array includes at least one of a convex surface and a concave surface.

[0015] In the embodiment of the present application, when the microstructure array of the diffusion screen is a microlens array, the surface shape of each microlens array is a free-form surface. At the same time, by designing the surface shape of the microlens array to be at least one of a convex surface or a concave surface, the diversity and flexibility of the design are increased.

[0016] In combination with the first aspect, in some implementations of the first aspect, the boundary shapes of the plurality of microlenses are irregular.

[0017] The irregular boundary shape can reduce the aberrations introduced by the diffusion screen during imaging, such as spherical aberration or distortion, thereby improving the imaging quality. At the same time, the irregular boundary shape of the microlens has lower requirements for processing accuracy, which can reduce the difficulty of processing and has lower requirements for processing accuracy.

[0018] In combination with the first aspect, in certain implementations of the first aspect, a surface of each microstructure in the microstructure array presents a concave-convex texture.

[0019] In combination with the first aspect, in certain implementations of the first aspect, the curvature of the first microstructure in the microstructure array is determined by the incident angle of the image light incident on the first microstructure, the deflection angle of the image light emitted by the first microstructure, and the diffusion angle of the image light emitted by the first microstructure, and the first microstructure is any one of the microstructures in the microstructure array.

[0020] By determining the curvature of each microstructure through the incident angle of the incident light, the target deflection angle of the outgoing light, and the diffusion angle of the outgoing light, precise control of the image light can be achieved, and the utilization rate of light energy can be improved. When applied to a display device, the brightness of the image and the performance of the display device can be guaranteed.

[0021] In a second aspect, an embodiment of the present application provides a display device. The display device includes a projection module, a first reflective element, a second reflective element, and a diffuser screen as described in the first aspect and any possible implementation of the first aspect. The projection module is used to project image light onto the diffuser screen; the diffuser screen is used to change the emission direction of the incident light and project the image light emitted from different positions onto the first reflective element at different deflection angles; the first reflective element is used to reflect the image light emitted from the diffuser screen to the second reflective element; and the second reflective element is used to reflect the image light reflected by the first reflective element to the human eye.

[0022] In a third aspect, an embodiment of the present application provides a vehicle, which includes a display device as described in the implementation of the second aspect above.

[0023] In a fourth aspect, an embodiment of the present application provides a vehicle-mounted system, which includes a display device as described in the implementation method of the second aspect above. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a solution that uses a field lens to match the direction of the projection light of the HUD device and the image light.

[0025] Figure 2 It is a schematic diagram of an application scenario of the HUD device provided in an embodiment of the present application.

[0026] Figure 3 This is a side view of a diffusion screen 300 provided in an embodiment of the present application.

[0027] Figure 4 A side view of a diffusion screen 400 provided in an embodiment of the present application.

[0028] Figure 5 This is a front view of a diffusion screen 500 provided in an embodiment of the present application.

[0029] Figure 6 A side view of another diffuser screen provided in an embodiment of the present application.

[0030] Figure 7 A schematic diagram of a display device 700 provided in an embodiment of the present application.

[0031] Figure 8 A possible structure of the projection module 701 provided in an embodiment of the present application.

[0032] Fig. 9 A possible structure of the projection module 701 in which the modulation module 712 is a DMD is provided for the embodiment of the present application.

[0033] Fig.10 A schematic diagram of an optical path 1000 of a display device 700 provided in an embodiment of the present application when applied to a vehicle.

[0034] Fig.11 A circuit diagram of a display device provided in an embodiment of the present application.

[0035] Fig.12 A schematic diagram of a possible functional framework of a vehicle provided in an embodiment of the present application. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0037] In order to facilitate understanding of the embodiments of the present application, the following explanation is made.

[0038] First, the terms "first", "second", etc. and various numbers in the text descriptions or drawings of the embodiments of the present application shown below are only used for the convenience of description, and are not necessarily used to describe a specific order or sequence, and are not used to limit the scope of the embodiments of the present application. For example, to distinguish curvatures in different directions, etc.

[0039] Second, the terms "including" and "having" and any variations thereof in the embodiments of the present application shown below are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or apparatuses.

[0040] Third, in the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions, and the embodiments or designs described as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. The use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way for easy understanding.

[0041] Fourth, in the embodiment of the present application, image light refers to light carrying an image (or image information) and is used to generate an image.

[0042] Fifth, in the drawings of the present application, the thickness, size and shape of each optical element have been slightly exaggerated for the sake of convenience. Specifically, the shapes of the optical elements shown in the drawings are shown by way of example. For example, the shape of the diffusion screen in the present application is not limited to the shapes shown in the drawings. Moreover, the drawings are only examples and are not drawn strictly to scale.

[0043] Sixth, unless otherwise defined, all terms (including technical terms and scientific terms) used in this application have the same meaning as commonly understood by a person of ordinary skill in the art to which this application belongs. It should also be understood that terms (such as terms defined in commonly used dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined in this article.

[0044] The diffusion screen provided in the embodiment of the present application can be applied to HUD devices. Figure 2 Schematic diagram of an application scenario of the HUD device provided in the embodiment of the present application. Figure 2As shown, the HUD device is installed on the car. The HUD device is used to project the vehicle status information, external object indication information and navigation information into the driver's field of vision through the vehicle's windshield. The status information includes but is not limited to driving speed, mileage, fuel level, water temperature and headlight status. The external object indication information includes but is not limited to safe vehicle distance, surrounding obstacles and reversing images. The navigation information includes but is not limited to direction arrows, distance and driving time.

[0045] Among them, the virtual image corresponding to the navigation information and the indication information of the external object can be superimposed on the real environment outside the vehicle, so that the driver can obtain the visual effect of augmented reality, for example, it can be used for augmented reality (AR) navigation, adaptive cruise, lane departure warning, etc. Since the virtual image corresponding to the navigation information can be combined with the real scene, the HUD device is usually coordinated with the advanced driving assistant system (ADAS) system of the car. In order not to interfere with the road conditions, the virtual image corresponding to the instrument information is usually about 2 to 3 meters away from the human eye. In order to better integrate the virtual image corresponding to the navigation information with the real road surface, the virtual image corresponding to the navigation information is generally about 7 to 15 meters away from the human eye. Among them, the position where the virtual image of the navigation information is located is called the far focal plane, and the plane where the virtual image of the instrument information is located is called the near focal plane.

[0046] Figure 3 1 is a side view of a diffuser screen 300 provided in an embodiment of the present application. Figure 3 As shown, the diffuser screen 300 includes a first surface 310 and a second surface 320, wherein the first surface 310 of the diffuser screen 300 includes a microstructure array 311, along a first direction ( Figure 3 The curvatures of the microstructures of the microstructure array 311 are different. The diffusion screen 300 is used to change the direction of the emitted image light in the first direction.

[0047] It should be noted that in the HUD system, the diffuser screen can generate a relay image using the image light emitted by the PGU, and fully disperse the incident image light to produce an optical diffusion effect, that is, the diffuser screen can increase the diffusion angle of the emitted image light. In the present application scheme, the diffuser screen 300 not only has the above-mentioned effects, but also has the function of changing the direction of the emitted image light in the first direction. Specifically, since the curvatures of the multiple microstructures of the diffuser screen 300 in the first direction are different, the microstructures with different curvatures have different deflection effects on the incident image light, so that the image light incident on the microstructures with different curvatures has different emission directions. Among them, the deflection effect of microstructures with different curvatures on the incident image light means that microstructures with different curvatures can change the direction of the main light in the incident image light, so that the direction of the main light is deflected, so that the center of the diffuse spot of the light emitted by different microstructures is deflected relative to the incident time. For example, as Figure 3 As shown, along the x direction of the diffuser screen, the microstructure array 311 of the first surface 310 of the diffuser screen 300 includes four microstructures (eg Figure 3 The four microstructures have different curvatures. Therefore, after the image light incident on the four microstructures passes through the four microstructures, the direction of the main light is deflected relative to the incident direction, and the deflection angle (such as Figure 3 α1, α2, α3, α4) are different.

[0048] In addition, it should be noted that the curvature of each microstructure in the microstructure array is determined by the incident angle of the image light incident on each different microstructure, the deflection angle of the image light emitted by each microstructure, and the diffusion angle of the image light emitted by each microstructure. Exemplarily, for microstructure #1, its curvature is determined by the incident angle β1, the deflection angle α1 and the diffusion angle γ1. Specifically, when the system requires that the deflection angle of the main light passing through microstructure #1 is α1 and the diffusion angle is γ1, the incident angle β1 of the image light emitted by the PGU in the HUD system when it is incident on microstructure #1 can be combined, and the above angle parameters can be preset in the optical path simulation system (such as zemax or codeV), and the curvature of microstructure #1 along the first direction can be obtained by optimization. Similarly, the process of determining the curvature of microstructure #2, microstructure #3 and microstructure #4 is the same as that of determining microstructure #1. After the curvature of each microstructure is obtained, the surface processing parameters of the diffusion screen 300 can be further generated for processing.

[0049] It should be noted that in Figure 3In the figure, the diffusing screen 300 is used as a transmission element to illustrate its deflection effect on the image light. In some embodiments, the diffusing screen 300 can also be used as a reflection element to deflect the direction of the emitted image light. At this time, the diffusing screen 300 makes the reflection angle of the main light of the reflected image light different from the incident angle of the image light, that is, the diffusing screen 300 deflects the main light of the reflected image light relative to the incident direction when it is incident. When the diffusing screen is used as a reflection element, the incident angle of the image light incident on each different microstructure, the deflection angle of the image light reflected by each microstructure, and the diffusion angle of the image light emitted by each microstructure are determined.

[0050] Optionally, the material of the diffusion screen 300 is polymethyl methacrylate (PMMA), polycarbonate (PC), optical glass, etc., which is not limited in the present application.

[0051] Optionally, the microstructure array 311 is a microlens array or a microstructure array with a concave-convex texture on the surface, which is not limited in the present application. Exemplarily, when the microstructure array 311 is a microlens array, the surface shape of each microlens in the microlens array can be a convex lens or a concave lens of a free-form surface, that is, the surface shape of the multiple microlenses of the microlens array includes at least one of a convex surface and a concave surface, as described below Figure 5 When the microstructure array 311 is a microstructure array with a concave-convex texture on the surface, the side view of the diffusion screen can be as shown in FIG. Figure 6 shown.

[0052] Optionally, in order to further reduce the aberration introduced by the microstructure and improve the imaging quality, the boundary of each microstructure is designed to be an irregular shape.

[0053] In some embodiments, in order to further improve the utilization rate of image light energy, the thicknesses of multiple microstructures in the microstructure array 311 can be designed to be different. In order to further reduce the diffraction effect generated when each microstructure in the microstructure array 311 transmits image light and improve the imaging quality, in more stringent scenarios, the thicknesses of any two microstructures can be designed to be different. The thickness of the microstructure refers to the length of the microlens along the optical axis direction of the light diffusion screen (or the main optical axis direction of the HUD device), for example Figure 3 The z-axis direction is shown.

[0054] It is understandable that in the diffuser screen 300, the curvatures of the four microstructures of the microstructure array 311 along the x direction are different. In other embodiments, the diffuser screen provided by the present application has a plurality of microstructures with different curvatures along the first direction, that is, the plurality of microstructures of the microstructure array have changes in the first direction, and it is not strictly required that the curvature of each microstructure in the first direction is different. For example, the curvatures of any two adjacent microstructures in the first direction may be different, or the curvatures of microstructures at any periodic interval in the first direction may be different.

[0055] Furthermore, it is understandable that Figure 3 The x-axis is used as the first direction for the purpose of illustration. In the present application, if the diffusion screen 300 is used to change the direction of the emitted image light in the first direction, the first direction may be any direction, that is, the first direction includes but is not limited to Figure 3 The x-axis direction shown may also be the y-axis direction, for example. It should be noted that the microstructure array of the diffusion screen provided in the present application is all over the first surface of the diffusion screen, that is, the microstructures are densely arranged on the first surface of the diffusion screen, as follows Figure 5 as shown in .

[0056] Based on the diffusion screen provided by the present application, the direction of the image light incident in the first direction can be changed by different curvatures of the microstructure in the first direction. When applied to a HUD device, it is possible to avoid using components such as field lenses to adjust the direction of the image light in the device, thereby achieving the purpose of reducing the volume of the HUD device. At the same time, the problem of reduced imaging quality caused by components such as field lenses can be avoided, thereby achieving the effect of improving imaging quality, and further achieving the purpose of improving the performance of the HUD device.

[0057] Figure 4 This is a side view of a diffusion screen 400 provided in an embodiment of the present application. Figure 4 (a) is a side view of the diffuser screen 400 in the xoz plane. Figure 4 (b) is a side view of the diffuser 400 in the yoz plane. The diffuser 400 includes a first surface 410 and a second surface 420, wherein the first surface 410 of the diffuser 400 includes a microstructure array 411, along a first direction (i.e. Figure 4 The curvatures of the microstructures of the microstructure array 411 are different. Meanwhile, along the second direction ( Figure 4 The curvatures of the plurality of microstructures of the microstructure array 411 are different, and the diffusion screen 400 is used to change the direction of the emitted image light in the first direction and the second direction at the same time.

[0058] and Figure 3 Compared with the diffuser screen 300 shown in FIG. 1 , the diffuser screen 400 is different in that the diffuser screen 400 can change the direction of the emitted image light in two directions. It can be understood that when Figure 4 When the diffuser 400 changes the direction of the emitted image light in two directions, the curvatures of the multiple microstructures of the microstructure array included in the diffuser 400 along the two directions are different. The deflection effect of each microstructure on the image light can be referred to above. Figure 3 The relevant description in will not be repeated here. It can also be understood that Figure 4 Only the change in the direction of the principal light rays caused by each microstructure is shown.

[0059] It should be noted that Figure 4 The diffusion screen 400 is shown as an example in which the first direction is the x direction and the second direction is the y direction, that is, only an embodiment in which the first direction and the second direction are perpendicular to each other is shown. In some other embodiments, the first direction and the second direction may be any other non-overlapping directions, which is not limited in the present application.

[0060] It can be understood that when the curvature of the plurality of microstructures of the diffuser screen 400 along the first direction or along the second direction does not change, that is, the curvature of the plurality of microstructures of the diffuser screen 400 along the first direction or along the second direction is the same, the diffuser screen 400 can be considered to change the direction of the image light in one direction. At this time, the diffuser screen 400 can be considered to be Figure 3 The diffuser screen 300 shown, i.e., the diffuser screen 300 can be regarded as Figure 4 A particular form of diffuser screen 400 is shown.

[0061] It can also be understood that, according to different usage scenarios of the diffuser screen 400, the diffuser screen 400 can be designed so that the deflection angle of the image by the multiple microstructures along the first direction is the same as or different from the deflection angle of the image by the multiple microstructures along the second direction, and this application does not limit this.

[0062] In addition, for the description of the surface type, boundary shape, thickness of each microstructure included in the microstructure array 411 of the diffusion screen 400, as well as other descriptions such as the material of the diffusion screen 400, reference can be made to the above Figure 3 The relevant parts of are not repeated here.

[0063] Based on the above solution, the diffuser provided by the present application can achieve the change of the image light direction in two directions, increasing the use scenarios of the diffuser. When applied to a HUD device, it can also make the position layout of other components more flexible, thereby improving the flexibility of the HUD device design.

[0064] Figure 5This is a front view of a diffuser screen 500 provided in an embodiment of the present application. Specifically, the diffuser screen 500 can change the direction of the emitted image light in the x-direction and the y-direction at the same time, that is, the curvatures of the multiple microstructures of the diffuser screen 500 in the x-direction and the y-direction vary. Figure 5 As shown, there is a microlens array formed by closely packed free-form surfaces of at least one concave surface and a convex surface on the surface of the diffusion screen 500, wherein the boundary shape of each microlens is irregular, and the thickness of adjacent lenses is different. When the image light is emitted from the z-axis, each microlens can change the direction of the emitted image light in the x-direction and the y-direction at the same time. That is, after emission, a diffuse light spot is formed with the center direction off-axis in both the x-direction and the y-direction.

[0065] Understandably, Figure 5 Only an embodiment is shown in which the diffusion screen changes the emission direction of the image light in two perpendicular directions, and the two directions are perpendicular to the thickness direction of the microstructure in pairs, but the present application is not limited thereto.

[0066] It should be noted that the above Figures 3 to 6 The diffuser screen shown in the figure is only shown with a cross-sectional shape of a rectangle. The shape of the diffuser screen provided in the present application is not limited thereto. In some other embodiments, the cross-sectional shape of the diffuser screen may also be circular (for example, the diffuser screen is a thin cylinder), irregular, etc.

[0067] Next, combining the above Figures 3 to 6 The diffusion screen shown in the figure illustrates some possible structures of the display device provided by the present application.

[0068] Figure 7 Schematic diagram of a display device 700 provided in an embodiment of the present application. Figure 7 As shown, the display device 700 includes a projection module 701, a diffusion screen 702, a first reflection element 703 and a second reflection element 704. The projection module 701 is used to project image light onto the diffusion screen 702. The diffusion screen 702 is used to change the emission direction of the incident image light, and project the image light emitted from different positions onto the first reflection element at different deflection angles. The first reflection element 703 is used to reflect the image light emitted from the diffusion screen 702 to the second reflection element 704. The second reflection element 704 is used to reflect the image light reflected by the first reflection element 703 to the human eye.

[0069] Optionally, the display device 700 may further include a dust cover 705. The dust cover 705 has the functions of isolating the external high temperature, preventing the internal temperature of the display device 700 from being too high, or preventing external dust from entering the device.

[0070] In the embodiment of the present application, the projection module 701 can adopt an LCoS display, an organic light-emitting diode (OLED) display, a liquid crystal display (LCD), a digital light processing (DLP) display or a micro-electro-mechanical system (MEMS) display, etc., which is not limited in the present application.

[0071] It should be noted that in Figure 7 In the display device 700 shown, the first reflective element 703 may be a concave mirror, a convex mirror or a plane mirror with a free-form surface, which is not limited in the present application.

[0072] It is understandable that the number of reflective elements included in the display device 700 is not limited to Figure 7 As shown, it can be adjusted accordingly according to needs.

[0073] As an example, Figure 8 A possible structure of the projection module 701 provided in the embodiment of the present application. The projection module 701 includes a light source 711, a modulation module 712, and a projection device 713. According to the different display technologies adopted by the projection module 701, the modulation module 712 can be an LCoS modulator, or a DMD, or a transmissive spatial light modulator LCD, etc. Exemplarily, when the modulation module 712 is an LCoS modulator, the light source 711 can be a red, green, and blue light emitting diode (light emitting diode) light source, and together with the LCoS modulator constitute an LCoS display. When the modulation module 712 is a DMD, it can be a DMD modulator under MEMS control, and a laser light source or an LED light source can be used to form a DLP display. Alternatively, when the modulation module 712 is an LCD modulator, the light source 711 can use a linear light source of a red, green, and blue cold cathode fluorescent tube, and form an LCD display with the LCD modulator. The projection device 713 can be a projection lens.

[0074] Optionally, in order to improve the projection quality and / or reduce the volume of the projection module 701, in some embodiments, the projection module 701 further includes a refraction module 714, or the projection module 701 further includes a polarization conversion module 714. When the projection module 701 includes a refraction module 714, the refraction module 714 may be one or more lenses (used to focus the energy of the light beam, ensure the energy of the light beam or diffuse the light spot, and increase the field of view of the projection), and / or one or more prisms (used to fold the light path and reduce the volume of the projection module), etc., which are not limited in this application. When the projection module 701 includes a polarization conversion module 714, the polarization conversion module 714 is used to change the polarization state of the image light.

[0075] As an example, Fig. 9 The present application provides a possible structure of the projection module 701 in which the modulation module 712 is a DMD. Fig. 9 As shown, the light source 711 includes a first monochromatic light array 911, a second monochromatic light array 912, a third monochromatic light array 913, dichroic filters 921 and 922, and a lens group 933. The three monochromatic light arrays can correspond to monochromatic light of three primary colors, including red light, blue light, and green light. In order to improve the utilization rate of light energy, in some embodiments, a collimating lens is further arranged after the monochromatic light array, as shown in FIG. Fig. 9 The collimating lens 9111, the collimating lens 9112 and the collimating lens 9113 in the projection module 701 are provided. The refraction module 714 includes a lens group and a prism. Figure 7 In the display device 700 shown, the first monochromatic light array 911, the second monochromatic light array 912, and the third monochromatic light array 913 respectively emit corresponding monochromatic lights. The three monochromatic lights pass through the dichroic filters 921 and 922 and are incident on the lens group of the refractive module. After being emitted from the lens group, they are incident on the DMD 712 through the prism. The DMD 712 modulates the input light beam based on the data information of the input image and outputs image light. The image light is transmitted through the prism and is incident on the projection lens 713. The image light is emitted toward the diffusion screen through the projection lens 713.

[0076] When the display device 700 is applied to a vehicle, Fig.10The display device provided in the embodiment of the present application is applied to a schematic diagram of an optical path 1000 of a vehicle. Specifically, the projection module 701 generates image light and projects the image light to the diffusion screen 702. The diffusion screen 702 changes the emission direction of the image light from the projection module 701, and emits the image light after the change of direction to the first reflection element 703. Then, the first reflection element 703 reflects the diffused image light to the second reflection element 704. After the image light is reflected by 704, it transmits through the light shield 705 and is reflected to the human eye through the windshield 1001 for imaging. Among them, the image generated by the image light can be an augmented reality display image, which is used to display information such as indication information and navigation information of external objects. Alternatively, the image generated by the image light can be a status display image, which is used to display the status information of the vehicle. Taking a car as an example, the status information of the vehicle includes but is not limited to information such as driving speed, mileage, fuel level, water temperature and light status.

[0077] It should be noted that the above Figure 7 The display device 700 shown is only one embodiment in which the diffuser provided by the present application is applied as a transmission element in a display device. In some other embodiments of the display device, the diffuser provided by the present application can also be used as a reflection element. In this case, the microstructures of different curvatures of the microstructure array on the surface of the diffuser screen make the reflection angle of the main light of the reflected image light different from the incident angle of the image light, that is, the diffuser screen causes the main light of the reflected image light to be deflected relative to the incident direction at the time of incidence.

[0078] It is understandable that the means of transportation to which the present application scheme can be applied include but are not limited to cars, airplanes, trains or ships.

[0079] In addition, the embodiment of the present application further provides a means of transportation, which is any of the above-mentioned display devices. The means of transportation includes but is not limited to a car, an airplane, a train, or a ship.

[0080] Fig.11 This is a circuit diagram of a display device provided in an embodiment of the present application. Fig.11As shown, the circuit in the display device mainly includes a host CPU 1201, an external memory interface 1202, an internal memory 1203, an audio module 1204, a video module 1205, a power module 1206, a wireless communication module 1207, an I / O interface 1208, a video interface 1209, a display circuit 1210 and a modulator 1212. Among them, the host processor 1201 and its peripheral components, such as the external memory interface 1202, the internal memory 1203, the audio module 1204, the video module 1205, the power module 1206, the wireless communication module 1207, the I / O interface 1208, the video interface 1209, and the display circuit 1210 can be connected through a bus. The host processor 1201 can be called a front-end processor.

[0081] In addition, the circuit diagrams shown in the embodiments of the present application do not constitute a specific limitation on the display device. In other embodiments of the present application, the display device may include more or fewer components than shown in the figure, or combine certain components, or split certain components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.

[0082] The main processor 1201 includes one or more processing units, for example, the main processor 1201 may include an application processor (AP), a modem processor, a graphics processor (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processor (NPU), etc. Different processing units may be independent devices or integrated in one or more processors.

[0083] The main processor 1201 may also be provided with a memory for storing instructions and data. In some embodiments, the memory in the main processor 1201 is a cache memory. The memory may store instructions or data that the main processor 1201 has just used or cyclically used. If the main processor 1201 needs to use the instruction or data again, it may be directly called from the memory. This avoids repeated access, reduces the waiting time of the main processor 1201, and thus improves the efficiency of the system.

[0084] In some embodiments, the display device may further include a plurality of input / output (I / O) interfaces 1208 connected to the main processor 1201. The interface 1208 may include an inter-integrated circuit (I2C) interface, an inter-integrated circuit sound (I2S) interface, a pulse code modulation (PCM) interface, a universal asynchronous receiver / transmitter (UART) interface, a mobile industry processor interface (MIPI), a general-purpose input / output (GPIO) interface, a subscriber identity module (SIM) interface, and / or a universal serial bus (USB) interface, etc. The above-mentioned I / O interface 1208 may be connected to devices such as a mouse, a touchpad, a keyboard, a camera, a speaker / speaker, a microphone, etc., and may also be connected to physical buttons on the display device (such as a volume button, a brightness adjustment button, a power button, etc.).

[0085] The external memory interface 1202 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the display device. The external memory card communicates with the main processor 1201 through the external memory interface 1202 to implement a data storage function.

[0086] The internal memory 1203 can be used to store computer executable program codes, which include instructions. The internal memory 1203 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system, an application required for at least one function (such as a call function, a time setting function, etc.), etc. The data storage area may store data created during the use of the display device (such as a phone book, world time, etc.), etc. In addition, the internal memory 1203 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, a universal flash storage (Universal Flash Storage, UFS), etc. The main processor 1201 executes various functional applications and data processing of the display device by running instructions stored in the internal memory 1203 and / or instructions stored in a memory provided in the main processor 1201.

[0087] The display device can implement audio functions such as music playing and calls through the audio module 1204 and the application processor.

[0088] The audio module 1204 is used to convert digital audio information into analog audio signal output, and is also used to convert analog audio input into digital audio signals. The audio module 1204 can also be used to encode and decode audio signals, such as playing or recording. In some embodiments, the audio module 1204 can be arranged in the main processor 1201, or some functional modules of the audio module 1204 can be arranged in the main processor 1201.

[0089] The video interface 1209 can receive external audio and video signals, which can be specifically a high-definition multimedia interface (HDMI), a digital video interface (DVI), a video graphics array (VGA), a display port (DP), etc. The video interface 1209 can also output video to the outside. When the display device is used as a head-up display, the video interface 1209 can receive speed signals and power signals input from peripheral devices, and can also receive external AR video signals. When the display device is used as a projector, the video interface 1209 can receive video signals input from an external computer or terminal device.

[0090] The video module 1205 can decode the video input by the video interface 1209, for example, by performing H.264 decoding. The video module can also encode the video collected by the display device, for example, by performing H.264 encoding on the video collected by the external camera. In addition, the main processor 1201 can also decode the video input by the video interface 1209, and then output the decoded image signal to the display circuit 1210.

[0091] The display circuit 1210 and the modulator 1212 are used to display the corresponding image. In this embodiment, the video interface 1209 receives an external video source signal, and the video module 1205 decodes and / or digitally processes and outputs one or more image signals to the display circuit 1210. The display circuit 1210 drives the modulator 1212 to image the incident polarized light according to the input image signal, and then outputs the image light. In addition, the main processor 1201 can also output one or more image signals to the display circuit 1210.

[0092] In this embodiment, the display circuit 1210 and the modulator 1212 belong to the above Figure 8The electronic components in the modulation unit 712 shown, the display circuit 1210 can be called a driving circuit.

[0093] The power module 1206 is used to provide power to the main processor 1201 and the light source 1200 according to the input power (e.g., direct current), and the power module 1206 may include a rechargeable battery, which can provide power to the main processor 1201 and the light source 1200. The light emitted by the light source 1200 can be transmitted to the modulator 1212 for imaging, thereby forming an image light signal.

[0094] The wireless communication module 1207 enables the display device to communicate wirelessly with the outside world, and can provide wireless local area networks (WLAN) (such as wireless fidelity (Wi-Fi) networks), Bluetooth (BT), global navigation satellite system (GNSS), frequency modulation (FM), near field communication technology (NFC), infrared technology (IR) and other wireless communication solutions. The wireless communication module 1207 can be one or more devices integrating at least one communication processing module. The wireless communication module 1207 receives electromagnetic waves via an antenna, modulates the frequency of the electromagnetic wave signal and performs filtering, and sends the processed signal to the main processor 1201. The wireless communication module 1207 can also receive the signal to be sent from the main processor 1201, modulate the frequency of it, amplify it, and convert it into electromagnetic waves for radiation through the antenna.

[0095] In addition, in addition to being input through the video interface 1209, the video data decoded by the video module 1205 can also be wirelessly received through the wireless communication module 1207 or read from an external memory. For example, the display device can receive video data from a terminal device or an in-vehicle entertainment system through the wireless LAN in the vehicle, and the display device can also read audio and video data stored in an external memory.

[0096] The above display device can be installed on a vehicle, see Fig.12 , Fig.12 A schematic diagram of a possible functional framework of a vehicle provided in an embodiment of the present application.

[0097] like Fig.12As shown, the functional framework of the vehicle may include various subsystems, such as the sensor system 12, the control system 14, one or more peripheral devices 16 (one is shown as an example), the power supply 18, the computer system 20 and the head-up display system 22. Optionally, the vehicle may also include other functional systems, such as an engine system that provides power for the vehicle, etc., which is not limited in this application.

[0098] The sensor system 12 may include a number of detection devices, which can sense the measured information and convert the sensed information into electrical signals or other required forms of information output according to a certain rule. As shown in the figure, these detection devices may include a global positioning system (GPS), a vehicle speed sensor, an inertial measurement unit (IMU), a radar unit, a laser rangefinder, a camera device, a wheel speed sensor, a steering sensor, a gear position sensor, or other components for automatic detection, etc., and the present application does not limit them.

[0099] The control system 14 may include several components, such as the steering unit, brake unit, lighting system, automatic driving system, map navigation system, network timing system and obstacle avoidance system shown in the figure. Optionally, the control system 14 may also include components such as a throttle controller and an engine controller for controlling the vehicle's speed, which are not limited in this application.

[0100] The peripheral device 16 may include several components, such as the communication system, touch screen, user interface, microphone, and speaker shown in the figure. The communication system is used to realize network communication between the vehicle and other devices other than the vehicle. In practical applications, the communication system may use wireless communication technology or wired communication technology to realize network communication between the vehicle and other devices. The wired communication technology may refer to communication between the vehicle and other devices through network cables or optical fibers.

[0101] The power source 18 represents a system that provides power or energy for the vehicle, which may include but is not limited to a rechargeable lithium battery or a lead-acid battery, etc. In practical applications, one or more battery components in the power source are used to provide power or energy for starting the vehicle, and the type and material of the power source are not limited in this application.

[0102] Several functions of the vehicle are controlled and implemented by the computer system 20. The computer system 20 may include one or more processors 2001 (one processor is shown as an example) and a memory 2002 (also referred to as a storage device). In actual applications, the memory 2002 is also inside the computer system 20, or it may be outside the computer system 20, for example, as a cache in the vehicle, etc., which is not limited in this application.

[0103] The processor 2001 may include one or more general-purpose processors, such as a graphics processing unit (GPU). The processor 2001 may be used to run related programs or instructions corresponding to the programs stored in the memory 2002 to implement corresponding functions of the vehicle.

[0104] The memory 2002 may include a volatile memory, such as a RAM; the memory may also include a non-volatile memory, such as a ROM, a flash memory, a HDD or a solid-state drive SSD; the memory 2002 may also include a combination of the above-mentioned types of memories. The memory 2002 may be used to store a set of program codes or instructions corresponding to the program codes, so that the processor 2001 calls the program codes or instructions stored in the memory 2002 to implement the corresponding functions of the vehicle. In the present application, a set of program codes for vehicle control may be stored in the memory 2002, and the processor 2001 calls the program codes to control the safe driving of the vehicle. How to achieve safe driving of the vehicle is described in detail below in the present application.

[0105] Optionally, in addition to storing program codes or instructions, the memory 2002 may also store information such as road maps, driving routes, sensor data, etc. The computer system 20 may be combined with other elements in the vehicle functional framework diagram, such as sensors in the sensor system, GPS, etc., to implement relevant functions of the vehicle. For example, the computer system 20 may control the driving direction or driving speed of the vehicle based on the data input from the sensor system 12, which is not limited in this application.

[0106] The head-up display system 22 may include several components, such as the windshield shown in the figure, a controller and a head-up display. The controller 222 is used to generate images according to user instructions (for example, images containing vehicle status such as vehicle speed, battery / fuel level, and images of augmented reality AR content), and send the image to the head-up display for display; the head-up display may include an image generation unit and a reflector combination, and the windshield is used to cooperate with the head-up display to realize the optical path of the head-up display system so that the target image is presented in front of the driver. Among them, the functions of some components in the head-up display system can also be implemented by other subsystems of the vehicle. For example, the controller can also be a component in the control system.

[0107] Among them, this application Fig.12 The four subsystems shown are sensor system 12, control system 14, computer system 20 and head-up display system 22, which are only examples and do not constitute limitations. In actual applications, vehicles can combine several components in the vehicle according to different functions to obtain subsystems with corresponding different functions. In actual applications, vehicles can include more or fewer systems or components, which is not limited in this application.

[0108] The above-mentioned means of transportation can be a car, truck, motorcycle, bus, ship, airplane, helicopter, lawn mower, recreational vehicle, amusement park vehicle, construction equipment, tram, golf cart, train, and cart, etc., and the embodiments of the present application are not particularly limited.

[0109] Unless otherwise defined, technical or scientific terms used herein shall have the common meanings understood by one of ordinary skill in the art to which the present disclosure belongs.

[0110] The above description is only an embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of the present application shall be included in the protection scope of the present application.

Claims

1. A diffusion screen, characterized in that: include: The first surface of the diffusion screen comprises a microstructure array, a plurality of microstructures of the microstructure array have different curvatures in a first direction, and the diffusion screen is used to change the direction of the emitted image light in the first direction.

2. The diffuser screen according to claim 1, characterized in that: The multiple microstructures of the microstructure array have different curvatures in the second direction, and the diffusion screen is used to change the direction of the emitted image light in the second direction.

3. The diffuser screen according to claim 1 or 2, characterized in that: The thicknesses of the plurality of microstructures in the microstructure array are different in the third direction.

4. The diffuser screen according to claim 3, characterized in that: Any two adjacent microstructures in the microstructure array have different thicknesses.

5. The diffuser screen according to claim 3 or 4, characterized in that: Two directions among the first direction, the second direction and the third direction are perpendicular to each other.

6. The diffuser screen according to any one of claims 1 to 5, characterized in that: The microstructure array is a microlens array.

7. The diffuser screen according to claim 6, characterized in that: The surface shapes of the plurality of microlenses of the microlens array include at least one of a convex surface and a concave surface.

8. The diffuser screen according to claim 6 or 7, characterized in that: The boundaries of the plurality of microlenses have irregular shapes.

9. The diffuser screen according to any one of claims 1 to 5, characterized in that: The surface of each microstructure in the microstructure array presents a concave-convex texture.

10. The diffuser screen according to any one of claims 1 to 9, characterized in that: The curvature of the first microstructure in the microstructure array is determined by the incident angle of the image light incident on the first microstructure, the deflection angle of the image light emitted by the first microstructure, and the diffusion angle of the image light emitted by the first microstructure, and the first microstructure is any microstructure in the microstructure array.

11. A display device, characterized in that: The device comprises a projection module, a first reflective element, a second reflective element and a diffusion screen as claimed in any one of claims 1 to 10, wherein: The projection module is used to project image light onto the diffusion screen; The diffusion screen is used to change the emission direction of the image light from the projection module, and project the image light emitted from different positions onto the first reflective element at different deflection angles; The first reflecting element is used to reflect the image light emitted by the diffusion screen to the second reflecting element; The second reflecting element is used to reflect the image light reflected by the first reflecting element to human eyes.

12. A means of transport, characterized in that: Comprising the display device as claimed in claim 11.

13. A vehicle-mounted system, characterized in that: Includes the display device according to claim 11.

Images