Diffusion screen, display device, onboard system and transportation means

Abstract

A diffusion screen (200, 402), a display device (400), an onboard system, and a transportation means. The diffusion screen (200, 402), when applied to the display device (400), can improve the quality of image displaying and the user experience. The diffusion screen (200, 402) comprises a first surface (210), wherein a microlens array is periodically and densely arranged on the first surface (210), and the microlens array enables diffraction angles corresponding to ±1st-order diffraction principal maxima of each wavelength in incident light after diffracted by the microlens array to be greater than or equal to a target diffusion angle.

Description

A diffuser screen, display device, vehicle system, and vehicle Technical Field

[0001] This application relates to the field of display technology and the field of intelligent vehicle driving technology, and more specifically, to a diffused screen, display device, vehicle system and vehicle. Background Technology

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

[0003] AR-HUD systems often use image generation units (PGUs) with display chips such as liquid crystal on silicon (LCOS) and digital micromirror devices (DMDs), paired with a diffuser screen. The image projected by the PGU is then relayed onto the diffuser screen. Since light passing through the diffuser screen is either scattered and transmitted or scattered and reflected, the angle and intensity distribution of the scattered light can be controlled by specially designing the microstructure of the diffuser screen surface, thereby improving the quality of the displayed image.

[0004] Currently, with the advancements in diffusion screen technology, the microlens size is approximately 20–50 micrometers. At this microlens scale, different wavelengths of projected light produce interlaced diffraction fringes, resulting in poor color and brightness uniformity in the displayed image, negatively impacting the viewing experience of the HUD. To address this issue, a common solution is to introduce random perturbations into each microlens unit, such as random lens center position, random lens curvature, and random lens aperture size. While these randomizations suppress diffraction fringes, they also introduce crosstalk or blanking at the boundaries between adjacent microlenses. This causes random scattering of light passing through these areas, resulting in black and bright spots in the displayed image, creating a "grainy" or "noise" effect, and reducing the clarity and detail of the image.

[0005] Summary of the Invention

[0006] This application provides a diffuser screen, a display device, an in-vehicle system, and a vehicle. When the diffuser screen provided by this application is applied to a display device, it can improve the quality of the displayed image, thereby enhancing the user experience.

[0007] In a first aspect, embodiments of this application provide a diffusion screen. The diffusion screen includes a first surface on which a periodically close-packed array of microlenses is disposed, wherein the microlens array causes the diffraction angles corresponding to the ±1st order principal maxima of each wavelength in the incident light after diffraction by the microlens array to be greater than or equal to the target diffusion angle.

[0008] Based on the above solution, the diffuser screen provided in this application reduces the diffraction effect by ensuring that the diffraction angles corresponding to the ±1st order principal maxima of each wavelength in the incident light after diffraction by the microlens array are greater than or equal to the target diffusion angle. This prevents the appearance of rainbow fringes caused by diffraction within the target diffusion angle. Furthermore, since the microlenses on the surface of the diffuser screen are periodically and closely arranged, random scattering of the incident light on the diffuser screen is prevented. Therefore, when the diffuser screen provided in this application is applied to a display device, within the human eye's field of vision, color stripes that degrade the uniformity of color and brightness of the displayed image are eliminated, and no noise appears on the displayed image. This significantly improves the display effect of the image, thereby enhancing the user experience.

[0009] In conjunction with the first aspect, in some implementations of the first aspect, each microlens of the microlens array is rectangular, and the period of the microlens array includes a first period and a second period, the values ​​of the first period and the second period are in the range of [0.6μm, 6μm], and the first period is smaller than the second period.

[0010] In conjunction with the first aspect, in some implementations of the first aspect, each microlens of the microlens array is square, and the period of the microlens array ranges from [0.6μm to 6μm].

[0011] The period range of the microlens array in this application is much smaller than the size of the projection resolution of the PGU, thus eliminating the loss of clarity of the display image caused by the diffused screen, thereby improving the display clarity.

[0012] In conjunction with the first aspect, in some implementations of the first aspect, the microlens array makes the diffraction angle corresponding to the ±1st order diffraction principal maxima of each wavelength in the incident light after diffraction by the microlens array greater than or equal to the target diffusion angle, including: the diffraction angle corresponding to the ±1st order diffraction principal maxima of the blue light in the incident light is greater than or equal to the target diffusion angle.

[0013] In conjunction with the first aspect, in some implementations of the first aspect, the angular difference Δθ between adjacent diffraction maxima of the blue light satisfies:

[0014] Where, λB λ is the wavelength of the incident blue light, and d is the period of the microlens array.

[0015] By limiting the diffraction angle corresponding to the ±1st order diffraction principal maxima of blue light, the design of the microlens array period on the diffusion screen in this application can be simplified.

[0016] Secondly, embodiments of this application provide a display device. The display device includes a projection module, an optical path folding module, and a diffusion screen provided in the first aspect or any of the above-described implementations of the first aspect. The projection module is used to project image light onto the diffusion screen; the diffusion screen is used to transmit or reflect the image light from the projection module to the optical path folding module; and the optical path folding module is used to reflect the image light from the diffusion screen toward a human eye.

[0017] In some embodiments, the diffusion screen provided in this application can also generate a relay image based on the image light from the projection module.

[0018] By applying the diffusion screen provided in this application to a display device, the diffraction effect of the displayed image can be reduced and noise in the displayed image can be eliminated, thereby improving the detail and clarity of the displayed image and achieving the effect of improving image quality.

[0019] In conjunction with the second aspect, in some implementations of the second aspect, the optical path folding module includes a first reflective element and a second reflective element, wherein the first reflective element is used to reflect image light from the diffuser screen to the second reflective element; and the second reflective element is used to reflect image light from the first reflective element toward the human eye.

[0020] Thirdly, embodiments of this application provide an in-vehicle system that includes a display device as described in the second aspect above.

[0021] Fourthly, embodiments of this application provide a means of transportation that includes a display device and a windshield as described in the second aspect above, or includes an in-vehicle system and the windshield as described in the third aspect above, wherein the windshield is used to reflect image light from the display device to the human eye. Attached Figure Description

[0022] Figure 1 is a schematic diagram of an application scenario of the HUD device provided in the embodiments of this application.

[0023] Figure 2 is a schematic diagram of a diffuser screen 200 provided in an embodiment of this application.

[0024] Figure 3 is a schematic diagram showing that the blue light diffraction principal maximum (i.e., minimum diffraction angle) and minimum half-width angle are greater than or equal to the diffusion angle required by the display device, according to an embodiment of this application.

[0025] Figure 4 is a schematic diagram of a display device 400 provided in an embodiment of this application.

[0026] Figure 5 is a schematic diagram of the optical path 1000 of the display device provided in the embodiment of this application applied to a vehicle.

[0027] Figure 6 is a circuit diagram of the display device provided in an embodiment of this application.

[0028] Figure 7 is a schematic diagram of a possible functional framework of a means of transportation provided in an embodiment of this application.

[0029] Figure 8 is a schematic functional block diagram of a mobile carrier 25 provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0031] The following description is provided to facilitate understanding of the embodiments of this application.

[0032] First, the terms "first," "second," and various numerical designations used in the textual descriptions or drawings of the embodiments of this application shown below are merely for descriptive convenience and are not intended to describe a specific order or sequence, nor are they used to limit the scope of the embodiments of this application. For example, "first surface," "second surface," etc., are used to distinguish different surfaces.

[0033] Second, the terms “comprising” and “having” and any variations thereof in the embodiments of this application shown below are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such processes, methods, products or devices.

[0034] Third, in the embodiments of this application, the words "exemplarily" or "for example" are used to indicate examples, illustrations, or descriptions. Embodiments or designs described as "exemplarily" or "for example" should not be construed as being more preferred or advantageous than other embodiments or designs. The use of words such as "exemplarily" or "for example" is intended to present the relevant concepts in a specific manner to facilitate understanding.

[0035] Fourth, in the embodiments of this application, image light refers to light carrying an image (or image information) used to generate an image, and can also be called imaging light.

[0036] Fifth, in the accompanying drawings of this application, the thickness, size, and shape of the various optical elements have been slightly exaggerated for ease of explanation. Specifically, the shapes of the optical elements shown in the drawings are illustrated by way of example; for instance, the shape of the diffuser screen in this application is not limited to the shape shown in the drawings. Furthermore, the drawings are merely illustrative and not strictly drawn to scale.

[0037] Sixth, unless otherwise specified, all terms used in this application (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. It should also be understood that terms (e.g., those defined in common dictionaries) shall be interpreted as having a meaning consistent with their meaning in the context of the relevant art and shall not be interpreted in an idealized or overly formal sense, unless expressly so defined herein.

[0038] In display systems, such as HUD systems or holographic optical element (HOE) systems, diffuser screens with surfaces designed as microlens arrays are often used to expand the light beam, thereby increasing the projected viewing range. However, when incident image light is transmitted or reflected through the microlens array, diffraction effects occur, resulting in rainbow stripes on the displayed image, affecting the user's viewing experience. To eliminate diffraction stripes, current technologies generally involve randomly arranging the surface shape or position of the microlenses to break the diffraction period, thereby improving the display effect. However, because the randomly arranged microstructures introduce random optical phase differences, noise with varying brightness appears in the displayed image. This not only fails to improve the image quality but also reduces the image sharpness, giving the image a grainy appearance.

[0039] In view of this, this application proposes a diffusion screen that, by ensuring that the diffraction angles of incident light of different wavelengths can cover the diffusion angle range required by the display device, and by reducing the size of the microlenses and arranging them in a regular manner, achieves the goal of eliminating rainbow patterns in principle. Furthermore, since the diffusion screen proposed in this application does not introduce asymmetrical random distribution, when applied to a display device, it also avoids the appearance of noise with sensitive variations in the displayed image, achieving a significant improvement in image clarity and detail.

[0040] The diffused screen provided in this application embodiment can be applied to HUD devices. Figure 1 is a schematic diagram of an application scenario of the HUD device applicable to this application embodiment. As shown in Figure 1, the HUD device is installed in a car. The HUD device is used to project vehicle status information, external object indication information, and navigation information through the vehicle's windshield into the driver's field of vision. Status information includes, but is not limited to, driving speed, mileage, fuel level, water temperature, and headlight status. External object indication information includes, but is not limited to, safe following distance, surrounding obstacles, and reversing camera image. Navigation information includes, but is not limited to, directional arrows, distance, and travel time.

[0041] The virtual images corresponding to navigation information and external object indications can be superimposed on the real environment outside the vehicle, giving the driver an augmented reality visual experience. This can be used for augmented reality (AR) navigation, adaptive cruise control, lane departure warning, and more. Because the virtual images corresponding to navigation information can be combined with the real-world scene, HUD devices are typically used in conjunction with the vehicle's advanced driver assistance system (ADAS).

[0042] It should be noted that the HUD device shown in Figure 1 is a single-focal-area display, but this application is not limited to this. That is, the HUD device applicable to the embodiments of this application can also be a HUD device in multi-focal-area application scenarios, etc. In addition, the HUD device applicable to the diffused screen provided in this application can be applied not only to vehicles, but also to driving tools such as ships, airplanes, and helicopters. This application does not make any limitation.

[0043] Figure 2 is a schematic diagram of a diffusion screen 200 provided in an embodiment of this application. In Figure 2(a), the diffusion screen 200 is a front view, and in Figure 2(b), the diffusion screen 200 is a side view. Specifically, as shown in Figure 2, the diffusion screen 200 includes a first surface 210, on which a periodically close-packed microlens array is arranged. The microlens array ensures that the diffraction angles corresponding to the ±1st order principal diffraction maxima of each wavelength in the incident light after diffraction by the microlens array are greater than or equal to the target diffusion angle.

[0044] It should be noted that in this application, the target diffusion angle can be understood as the diffusion angle required by the display device using the diffusion screen, or as the design angle of the diffusion screen. For example, if the diffusion screen 200 is used in a HUD device, when the target diffusion angle is understood as the diffusion angle required by the display device using the diffusion screen, the target angle is the diffusion angle when the HUD device is in use, i.e., the angle covered by the eye box range of the HUD device; or, when the target diffusion angle is understood as the design angle of the diffusion screen, the target angle is the angle of the image light emitted from the diffusion screen in the HUD device. Generally, the target diffusion angle can be set according to the designer's experience or product requirements. It is understood that due to the periodically densely packed microlens array on the first surface 210, the image light emitted from the PGU is transmitted through the diffusion screen 200 or reflected on the first surface 210 to form diffraction fringes. According to the Fraunhofer multi-slit diffraction principle, the 0th order principal maxima of each wavelength in the image light are basically coincident; therefore, no colored diffraction fringes are generated near the 0th order principal maxima, but bright white fringes are formed instead. Near the principal maxima of diffraction at various wavelengths, the different diffraction angles of each wavelength cause the colored light of each wavelength to be separated, forming rainbow fringes. Therefore, to avoid observing rainbow fringes within the target diffusion angle range, this application designs the microlens array on the diffusion screen so that the diffraction angles corresponding to the ±1st order principal maxima of each wavelength are greater than or equal to the target diffusion angle. That is, when the target diffusion angle is less than the diffraction angles corresponding to the ±1st order principal maxima of each wavelength, the dispersion caused by diffraction is outside the observation range, and therefore the rainbow fringes will not be observed. In other words, when the period of the diffraction fringes of each wavelength is greater than the target diffusion angle, there will be no diffraction fringes within the target diffusion angle range. For example, for a HUD device, when the diffraction angles corresponding to the ±1st order diffraction principal maxima of each wavelength are all greater than or equal to the eye box range of the HUD device, that is, the diffraction fringe period of each wavelength exceeds the eye box range of the HUD device, or when the diffraction angles corresponding to the ±1st order diffraction principal maxima of each wavelength are all greater than or equal to the design angle of the image light emitted from the PGU (or the diffusion angle of the diffusion screen), then rainbow patterns caused by diffraction will not be observed within the eye box range of the HUD device, thereby achieving the purpose of eliminating rainbow patterns.

[0045] It is understandable that the image light emitted from the PGU is composed of three colors of light combined in different proportions, namely red, green and blue light. According to the multi-slit diffraction law, the difference in diffraction angle between adjacent diffraction principal maxima can be expressed by the following equation (1).

[0046] Where λ is the wavelength of the incident light, and d is the grating constant, which in this application represents the size of the microlens, i.e., the period of the microlens array. It can be seen that for RGB light, since red light has the longest wavelength and blue light has the shortest wavelength, in this application, to ensure that the diffraction angles corresponding to the ±1st order diffraction principal maxima of each wavelength are greater than or equal to the target diffusion angle, when the Δθ of the blue light is greater than the target diffusion angle, colored stripes will not appear within the observation range of the display device. At this time, the angle difference Δθ between adjacent diffraction maxima of the blue light satisfies: Where, λ B Let λ be the wavelength of the incident blue light. For example, as shown in Figure 3, when the target diffusion angle is within the eye box range of the HUD device, if the diffraction angle corresponding to the ±1st order diffraction principal maxima of the blue light is greater than the target diffusion angle range of the HUD device, then no diffraction rainbow pattern will be observed within the eye box range of the HUD device.

[0047] It should be noted that in practical applications, the diffraction angle corresponding to the ±1st order diffraction principal maxima of blue light can be slightly smaller than the target diffusion angle. In this case, although there may be blue stripes at the edge of the display device's eye box, this is permissible because the image quality requirements at the edge of the eye box are usually low.

[0048] In the diffusion screen 200 provided in this application, the shape of each microlens is not limited; it can be rectangular, other polygonal, or circular. Similarly, the surface shape of each microlens is not limited; it can be a concave freeform mirror or a convex freeform mirror. However, it should be noted that the surface shape of each microlens in the microlens array must be consistent to form a periodically arranged array.

[0049] It should be noted that, in this application, the period of the microlens array can be understood as the distance between the centers of two adjacent microlenses in a closely packed array, or as the diameter of each microlens, i.e., the maximum distance between any two points on each microlens, or the diameter of the circumcircle of each microlens, etc. In some embodiments, if each microlens in the microlens array is rectangular, the period of the microlens array will include a long period and a short period, wherein the short period can be called the first period and the long period can be called the second period, and the values ​​of the first period and the second period are in the range of [0.6μm, 6μm]. In other embodiments, if each microlens in the microlens array is square, the period of the microlens array is one, and the value of the period of the microlens array composed of square microlenses is in the range of [0.6μm, 6μm]. It can be understood that, for rectangular microlenses, since there is a long period and a short period, the angle difference Δθ between adjacent diffraction maxima of blue light includes a first angle difference calculated using the long period and a second angle difference calculated using the short period. For example, if the long period and short period of the rectangular microlens are the periods along the x-axis and y-axis, respectively, then the angle difference Δθx calculated for the long period is the angle difference between adjacent diffraction maxima of the blue light diffracted along the x-axis, and the angle difference Δθy calculated for the short period is the angle difference between adjacent diffraction maxima of the blue light diffracted along the y-axis.

[0050] In current display devices, the image pixel size in the PGU is approximately 40 to 100 μm. Therefore, the period range of the microlens array in this application is much smaller than the size of the PGU's projection resolution, thus eliminating the loss of clarity in the displayed image caused by the diffuser screen, thereby improving display clarity. Simultaneously, because the microlenses are arranged in a perfectly regular pattern, no noise is generated in the displayed image, contributing to improved image detail.

[0051] In this application, the diffuser screen 200 shown in Figure 2 can be either a transmissive diffuser screen or a reflective diffuser screen. It is understood that Figure 2 is only shown as an example where the first surface 210 is the incident surface of the image light; that is, when the diffuser screen 200 is a transmissive diffuser screen, the second surface 220 opposite to the first surface 210 is the exit surface of the image light. In some embodiments, the second surface 220 can also be used as the incident surface of the image light, and the first surface 210 as the exit surface of the image light. The second surface 220 of the diffuser screen 200 is designed to be planar. It is also understood that when the diffuser screen 200 shown in Figure 2 is a reflective diffuser screen, the first surface 210 is both the incident and exit surface of the image light, meaning the image light is reflected from the first surface 210.

[0052] Optionally, the material of the diffuser screen 200 provided in this application may be polymethyl methacrylate (PMMA), polycarbonate (PC), optical glass, etc., and this application does not limit it.

[0053] Next, with reference to the diffusion screen shown in Figure 2 above, some possible structures of the display device provided in this application will be described.

[0054] Figure 4 is a schematic diagram of a display device 400 provided in an embodiment of this application. As shown in Figure 4, the display device 400 includes a projection module 401, a diffusion screen 402, and an optical path folding module 403. The projection module 401 projects image light onto the diffusion screen 402. The diffusion screen 402 transmits the image light from the projection module to the optical path folding module 403. The optical path folding module 403 reflects the image light from the diffusion screen 402 toward the human eye.

[0055] In some embodiments, the diffuser screen 402 can also generate a relay image based on the received image light. The relay image can be understood as an intermediate image generated by the display device 400, which has the same content as the image generated by the display device 400, but differs in size. That is, in the display device 400, the diffuser screen 402 displays a smaller image. The relay image has the same content as the image source in the image generation unit 410 and the image displayed by the display device.

[0056] It should be noted that in the display device 400 shown in FIG4, the diffuser 402 is the diffuser shown in FIG2 above, as well as other diffusers not listed in the embodiments of this application. It is understood that in the display device shown in FIG4, the diffuser 402 is used to transmit image light. In some embodiments, the diffuser 402 can also be a reflective diffuser, that is, the diffuser provided in the embodiments of this application can be a transmissive or a reflective diffuser.

[0057] This application does not limit the number and type of components included in the optical path folding module 403, and can adjust them accordingly as needed. Optionally, the optical path folding module 403 includes a first reflective element 43 and a second reflective element 44 (refer to the example in Figure 5 below). The first reflective element 43 is used to reflect the image light emitted from the diffuser screen 402 to the second reflective element 44. The second reflective element 44 is used to reflect the image light reflected by the first reflective element 43 towards the human eye. Both the first reflective element 43 and the second reflective element 44 can be concave mirrors, convex mirrors, or plane mirrors with freeform surface shapes; this application does not impose any limitations.

[0058] Optionally, the display device 400 may also include a dust cover 404. The dust cover 404 has the function of isolating the display device 400 from high external temperatures to prevent the internal temperature from becoming too high, or preventing external dust from entering the device.

[0059] In the embodiments of this application, the projection module 401 may be 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., and this application does not limit it.

[0060] When the display device 400 is applied to a vehicle, Figure 5 is a schematic diagram of the optical path 1000 of the display device applied to a vehicle according to an embodiment of this application. Specifically, the projection module 401 generates image light and projects the image light onto the diffusion screen 402. The diffusion screen 402 changes the emission direction of the image light from the projection module 401 and emits the changed image light onto the first reflective element 43. Subsequently, the first reflective element 43 reflects the diffused image light to the second reflective element 44. After being reflected by the second reflective element 44, the image light is reflected by the transmission light shield 404 through the windshield 1001 to the human eye for imaging. The image generated by the image light can be an augmented reality display image, 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, 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 headlight status.

[0061] It should be noted that the display device 400 shown in Figure 4 above is only one embodiment of the diffuser screen provided in this application as a transmission element applied to a display device. In some other embodiments of the display device, the diffuser screen provided in this application can also be used as a reflection element. In this case, the image light reflected by the microlens array on the surface of the diffuser screen 402 is sent to the first reflection element 43.

[0062] It is understood that the means of transportation to which this application can be applied include, but are not limited to, automobiles, airplanes, trains, or ships.

[0063] Furthermore, this application also provides a means of transportation that is any of the aforementioned display devices. The means of transportation includes, but is not limited to, automobiles, airplanes, trains, or ships.

[0064] Figure 6 is a circuit diagram of the display device provided in an embodiment of this application. As shown in Figure 6, the circuit in the display device mainly includes a main processor (host CPU) 1201, an external memory interface 1202, an internal memory 1203, an audio module 1204, a video module 1205, a power supply module 1206, a wireless communication module 1207, an I / O interface 1208, a video interface 1209, a display circuit 1210, and a modulator 1212. The main 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 supply module 1206, the wireless communication module 1207, the I / O interface 1208, the video interface 1209, and the display circuit 1210, can be connected via a bus. The main processor 1201 can be referred to as a front-end processor.

[0065] Furthermore, the circuit diagrams illustrated in the embodiments of this application do not constitute a specific limitation on the display device. In other embodiments of this application, the display device may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0066] The main processor 1201 includes one or more processing units, such as an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural network processing unit (NPU). These different processing units can be independent devices or integrated into one or more processors.

[0067] The main processor 1201 may also include a memory for storing instructions and data. In some embodiments, the memory in the main processor 1201 is a cache memory. This memory can store instructions or data that the main processor 1201 has just used or is recurring. If the main processor 1201 needs to use the instruction or data again, it can directly retrieve it from the memory. This avoids repeated accesses, reduces the waiting time of the main processor 1201, and thus improves the efficiency of the system.

[0068] In some embodiments, the display device may further include multiple input / output (I / O) interfaces 1208 connected to the main processor 1201. Interfaces 1208 may include Inter-Integrated Circuit (I2C) interfaces, Inter-Integrated Circuit Sound (I2S) interfaces, Pulse Code Modulation (PCM) interfaces, Universal Asynchronous Receiver / Transmitter (UART) interfaces, Mobile Industry Processor Interface (MIPI) interfaces, General-Purpose Input / Output (GPIO) interfaces, Subscriber Identity Module (SIM) interfaces, and / or Universal Serial Bus (USB) interfaces, etc. The aforementioned I / O interfaces 1208 can connect to devices such as mice, touchpads, keyboards, cameras, speakers, microphones, etc., and can also connect to physical buttons on the display device (e.g., volume buttons, brightness adjustment buttons, power buttons, etc.).

[0069] 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 perform data storage functions.

[0070] Internal memory 1203 can be used to store executable program code, including instructions. Internal memory 1203 may include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as a call function, 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.). Furthermore, internal memory 1203 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, 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 internal memory 1203 and / or instructions stored in memory located in the main processor 1201.

[0071] The display device can implement audio functions, such as music playback and phone calls, through the audio module 1204 and application processor.

[0072] The audio module 1204 is used to convert digital audio information into analog audio signals for output, and also to convert analog audio input into digital audio signals. The audio module 1204 can also be used for encoding and decoding audio signals, such as for playback or recording. In some embodiments, the audio module 1204 may be located in the main processor 1201, or some functional modules of the audio module 1204 may be located in the main processor 1201.

[0073] The video interface 1209 can receive externally input audio and video signals, specifically including High Definition Multimedia Interface (HDMI), Digital Visual Interface (DVI), Video Graphics Array (VGA), and DisplayPort (DP). The video interface 1209 can also output video. When the display device is used as a head-up display, the video interface 1209 can receive speed and power signals from peripheral devices, as well as externally input AR video signals. When the display device is used as a projector, the video interface 1209 can receive video signals from an external computer or terminal device.

[0074] The video module 1205 can decode the video input from the video interface 1209, such as performing H.264 decoding. The video module can also encode video captured by the display device, such as performing H.264 encoding on video captured by an external camera. Furthermore, the main processor 1201 can also decode the video input from the video interface 1209 and then output the decoded image signal to the display circuit 1210.

[0075] The display circuit 1210 and modulator 1212 are used to display the corresponding image. In this embodiment, the video interface 1209 receives an externally input video source signal. After decoding and / or digitizing the video module 1205, it 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.

[0076] In this embodiment, the display circuit 1210 can be referred to as the driving circuit.

[0077] The power module 1206 provides power to the main processor 1201 and the light source 1200 based on the input power (e.g., DC power). 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.

[0078] The wireless communication module 1207 enables the display device to communicate wirelessly with the outside world. It can provide solutions for wireless communication such as Wireless Local Area Networks (WLAN) (e.g., Wireless Fidelity (Wi-Fi)), Bluetooth (BT), Global Navigation Satellite System (GNSS), Frequency Modulation (FM), Near Field Communication (NFC), and Infrared (IR). 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 and filters the electromagnetic wave signal, and sends the processed signal to the main processor 1201. The wireless communication module 1207 can also receive signals to be transmitted from the main processor 1201, modulate and amplify them, and then convert them into electromagnetic waves for radiation via the antenna.

[0079] In addition, the video data decoded by the video module 1205 can be input not only through the video interface 1209, but also wirelessly received through the wireless communication module 1207 or read from external memory. For example, the display device can receive video data from the terminal device or the in-vehicle entertainment system through the vehicle's wireless local area network, and the display device can also read audio and video data stored in external memory.

[0080] The aforementioned display device can be installed on a vehicle. Please refer to Figure 7, which is a schematic diagram of a possible functional framework of a vehicle provided in an embodiment of this application.

[0081] As shown in Figure 7, the functional framework of a vehicle may include various subsystems, such as the sensor system 12, control system 14, one or more peripheral devices 16 (one is shown as an example), power supply 18, computer system 20, and head-up display system 22. Optionally, the vehicle may also include other functional systems, such as an engine system that provides power to the vehicle, etc., which are not limited herein.

[0082] The sensor system 12 may include several detection devices that 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 sensor, or other components used for automatic detection, etc., and this application does not limit them.

[0083] The control system 14 may include several components, such as the steering unit, braking unit, lighting system, automatic driving system, map navigation system, network time synchronization 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; this application is not limiting.

[0084] 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 enable network communication between the vehicle and other devices. In practical applications, the communication system can employ wireless or wired communication technologies to achieve network communication between the vehicle and other devices. The wired communication technology can refer to communication between the vehicle and other devices via network cables or fiber optic cables.

[0085] Power source 18 represents a system that provides electricity or energy to the vehicle, which may include, but is not limited to, rechargeable lithium batteries or lead-acid batteries. In practical applications, one or more battery components in the power source are used to provide electrical energy or power for vehicle startup, and the type and materials of the power source are not limited in this application.

[0086] 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 (the figure shows one processor as an example) and a memory 2002 (also called a storage device). In practical applications, the memory 2002 may be located inside the computer system 20 or outside the computer system 20, for example, as a cache in the vehicle, etc., which is not limited in this application.

[0087] in,

[0088] Processor 2001 may include one or more general-purpose processors, such as a graphics processing unit (GPU). Processor 2001 can be used to run relevant programs or instructions corresponding to programs stored in memory 2002 to implement the corresponding functions of the vehicle.

[0089] The memory 2002 may include volatile memory, such as RAM; it may also include non-volatile memory, such as ROM, flash memory, HDD, or SSD; or it may include a combination of the above types of memory. The memory 2002 can be used to store a set of program code or instructions corresponding to the program code, so that the processor 2001 can call the program code or instructions stored in the memory 2002 to implement the corresponding functions of the vehicle. In this application, the memory 2002 may store a set of program code for vehicle control. The processor 2001 can call this program code to control the safe driving of the vehicle. The specific details of how to achieve safe vehicle driving are described below in this application.

[0090] Optionally, in addition to storing program code or instructions, the memory 2002 may also store information such as road maps, driving routes, and sensor data. The computer system 20 can be integrated with other components in the vehicle functional framework diagram, such as sensors in the sensor system and GPS, to realize the vehicle's related functions. For example, the computer system 20 can control the vehicle's direction of travel or speed based on data input from the sensor system 12; this application does not impose limitations on this.

[0091] The head-up display system 22 may include several components, such as the windshield, controller, and head-up display shown in the figure. The controller 222 generates images according to user instructions (e.g., images containing vehicle status such as speed, battery / fuel levels, and augmented reality (AR) content) and sends these images to the head-up display for display. The head-up display may include an image generation unit and a reflector assembly. The windshield works in conjunction with the head-up display to establish the optical path of the head-up display system, so that the target image is presented in front of the driver. Some of the functions of the 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 within the control system.

[0092] Figure 7 of this application illustrates four subsystems: sensor system 12, control system 14, computer system 20, and head-up display system 22. These are merely examples and do not constitute a limitation. In practical applications, vehicles can combine various components according to different functions to obtain subsystems with corresponding functions. In practical applications, vehicles may include more or fewer systems or components; this application does not impose any limitations.

[0093] The aforementioned vehicles may include cars, trucks, motorcycles, buses, boats, airplanes, helicopters, lawnmowers, recreational vehicles, amusement park vehicles, construction equipment, trams, golf carts, trains, and handcarts, etc., and the embodiments of this application do not impose any special limitations.

[0094] Figure 8 is a schematic functional block diagram of a mobile carrier 25 provided in an embodiment of this application. The mobile carrier 25 may include a sensing system 120, a display device 130, and a computing platform 150. The sensing system 120 may include one or more sensors for sensing information about the environment surrounding the mobile carrier 25. For example, the sensing system 120 may include a positioning system, which may be a global positioning system (GPS), a BeiDou system or other positioning systems, an inertial measurement unit (IMU), lidar, millimeter-wave radar, ultrasonic radar, and one or more of a camera device.

[0095] Some or all of the functions of the mobile carrier 25 can be controlled by the computing platform 150. The computing platform 150 may include one or more processors, such as processor 151, processors 152 to 15n (n is a positive integer). A processor is a circuit with signal processing capabilities. In one implementation, the processor may be a circuit with instruction read and execute capabilities, such as a CPU, microprocessor, GPU (which can be understood as a type of microprocessor), or DSP, etc. In another implementation, the processor can implement certain functions through the logical relationship of hardware circuits. The logical relationship of the hardware circuits is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as a field-programmable gate array (FPGA). In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. Furthermore, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), tensor processing unit (TPU), deep learning processing unit (DPU), etc. In addition, the computing platform 150 may also include a memory for storing instructions. Some or all of the processors 151 to 15n can call and execute the instructions in the memory to achieve the corresponding functions. The display device 130 in the cockpit is a display device suitable for the embodiments of this application, such as the display device 400 in the above embodiments.

[0096] The mobile carrier in this application can include road vehicles, water vehicles, air vehicles, or entertainment equipment. For example, the mobile carrier can be a vehicle, which is a vehicle in a broad sense, and can be a means of transportation (such as commercial vehicles, passenger cars, trains, etc.), amusement equipment, toy vehicles, etc. The embodiments of this application do not specifically limit the type of vehicle. As another example, the mobile carrier can be a means of transportation such as an airplane or a ship.

[0097] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains.

[0098] The above description is only one embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc. made on the basis of this application should be included within the protection scope of this application.

Claims

1. A diffusion screen, characterized in that, include: First surface, The first surface has a periodically close-packed microlens array, wherein the microlens array makes the diffraction angle corresponding to the ±1st order diffraction principal maxima of each wavelength in the incident light after diffraction by the microlens array greater than or equal to the target diffusion angle.

2. The diffusion screen according to claim 1, characterized in that, Each microlens in the microlens array is rectangular, and the period of the microlens array includes a first period and a second period, the values ​​of the first period and the second period are in the range of [0.6μm, 6μm], and the first period is shorter than the second period.

3. The diffusion screen according to claim 1, characterized in that, Each microlens in the microlens array is square, and the period of the microlens array ranges from [0.6μm to 6μm].

4. The diffusion screen according to any one of claims 1 to 3, characterized in that, The microlens array ensures that the diffraction angles corresponding to the ±1st order principal maxima of each wavelength in the incident light after diffraction by the microlens array are greater than or equal to the target diffusion angle, including: The diffraction angle corresponding to the ±1st order diffraction principal maxima of the blue light in the incident light is greater than or equal to the target diffusion angle.

5. The diffusion screen according to claim 4, characterized in that, The angular difference Δθ between adjacent diffraction maxima of the blue light satisfies: Where, λ B λ is the wavelength of the incident blue light, and d is the period of the microlens array.

6. A display device, characterized in that, It includes a projection module, an optical path folding module, and a diffusion screen as described in any one of claims 1 to 5, wherein, The projection module is used to project image light onto the diffusion screen; The diffusion screen is used to transmit or reflect image light from the projection module to the optical path folding module; The optical path folding module is used to reflect image light from the diffuser screen to the human eye.

7. The display device according to claim 6, characterized in that, The optical path folding module includes a first reflective element and a second reflective element, wherein, The first reflective element is used to reflect image light from the diffuser screen to the second reflective element; The second reflective element is used to reflect image light from the first reflective element to the human eye.

8. A vehicle-mounted system, characterized in that, Includes the display device as described in claim 6 or 7.

9. A means of transportation, characterized in that, Includes the display device and windshield as described in claim 6 or 7, or includes the vehicle system and windshield as described in claim 8. The windshield is used to reflect image light from the display device to the human eye.

Images