Invisible pixel display device applied to exterior trim of vehicle body and processing method of invisible pixel display device

Abstract

The invention discloses an invisible pixel display device applied to vehicle body exterior decoration and a processing method thereof, and relates to the technical field of intelligent illumination, the invisible pixel display device comprises a surface colored paint layer, an embossment shading layer and an LED light emitting layer which are sequentially stacked, and the LED light emitting layer is electrically connected with a control unit; the surface colored paint layer is a transparent or semitransparent substrate, and a uniform colored paint layer is arranged on one surface, facing an observer, of the surface colored paint layer; the embossment shading layer comprises a pixel unit array and a shading area, the pixel unit array is a transversely and longitudinally arranged microstructure array, and the shading area covers the area outside the pixel unit array; the LED light-emitting layer comprises LED arrays, and the LED arrays are in one-to-one correspondence with the pixel unit arrays in position; the control unit is used for receiving the image signal and driving specific LEDs in the LED array to be lightened according to a preset pattern. The invention provides a display device which can realize real visual invisibility in a closed state and can give consideration to high resolution and high visual angle stability in a lighted state.

Description

Technical Field

[0001] This application relates to the field of intelligent lighting technology, and in particular to an invisible pixel display device and processing method for use in vehicle exterior trim. Background Technology

[0002] Currently, there are two main ways to implement luminous display technology for vehicle exteriors: one is to laser engrave the surface of components such as bumpers to form hollow or thin areas, and then arrange LED light strips on the back to present patterns through light transmission; however, even when not illuminated, the outline of the pattern will still be faintly visible due to differences in surface morphology, affecting the integrity and concealment of the vehicle's appearance.

[0003] Another approach is to fabricate a micropore array on the car paint layer, utilizing the properties of micropores that transmit and scatter light when illuminated, and are invisible to the naked eye when not illuminated due to their tiny size, to achieve "invisible display". However, such micropore structures rely on a single light transmission path, resulting in fixed and monotonous display patterns. They also lack the ability to actively control ambient light, and are prone to insufficient contrast or even blurry patterns under strong sunlight or at specific viewing angles, leading to poor visual stability of the displayed content.

[0004] Therefore, how to provide a display device that not only achieves true "visual invisibility" when turned off, but also balances high resolution and high viewing angle stability when lit has become a research focus for those skilled in the art. Summary of the Invention

[0005] In order to provide a display device that not only achieves true "visual invisibility" when turned off, but also maintains high resolution and high viewing angle stability when lit, this application provides an invisible pixel display device and its processing method for use in vehicle exterior trim.

[0006] Firstly, the objective of this invention is achieved through the following technical solution: An invisible pixel display device for vehicle exterior trim includes a surface paint layer, an embossed light-shielding layer, and an LED light-emitting layer stacked sequentially, wherein the LED light-emitting layer is electrically connected to a control unit; The surface paint layer is a transparent or semi-transparent substrate, and a uniform paint layer is provided on the side facing the observer; the embossed light-shielding layer includes a pixel unit array and a light-shielding area, the pixel unit array is a horizontally and vertically arranged microstructure array, and the light-shielding area covers the area outside the pixel unit array; the LED light-emitting layer includes a PCB substrate and an LED array located on the PCB substrate, and the LED array corresponds one-to-one with the pixel unit array. The control unit is used to receive image signals and drive specific LEDs in the LED array to light up according to a preset pattern.

[0007] By adopting the above technical solution, the light-shielding area is covered by a non-transparent material covering the area outside the pixel unit array. Specifically, in order to provide a display device that not only achieves true "visual invisibility" in the off state but also maintains high resolution and high viewing angle stability in the on state, the present invention sets up a surface paint layer, an embossed light-shielding layer, and an LED light-emitting layer stacked in sequence. The surface paint layer is a transparent or semi-transparent substrate, and the side facing the observer has a uniform paint layer, so that the embossed light-shielding layer has no pattern marks when not lit, and is consistent with the original paint surface. The embossed light-shielding layer includes micro-pixel units corresponding one-to-one with the LED array and non-transparent light-shielding areas. Thus, in the off state, the pattern is "completely invisible" by means of the physical shielding of the embossed light-shielding layer and the color consistency of the surface paint layer. The embossed light-shielding layer physically isolates non-pixel areas and suppresses background light interference. In the on state, the LED light in the LED array can only be controlled to pass through from the pixel unit position. Combined with the suppression of stray light by the embossed structure, the display contrast is significantly improved. Furthermore, the multi-layered collaborative structure can effectively match different vehicle body surfaces and ambient lighting conditions, maintaining stable visual performance under multi-angle observation. This fundamentally solves the technical defects of existing micro-hole or laser engraving solutions, which suffer from display failure or insufficient concealment under strong ambient light interference. Simultaneously, the control unit can flexibly configure the display content through software, adapting to various intelligent interactive scenarios such as welcome lights, brand logos, and safety warnings. This effectively overcomes the technical bottlenecks of existing technologies, which can only achieve fixed patterns, lack dynamic response, and have poor environmental adaptability. The invisible pixel display device of this application is suitable for different lighting conditions and vehicle body surfaces.

[0008] In a preferred embodiment of this application: each pixel unit in the pixel unit array is a raised or recessed structure, and its shape includes a star, rhombus, polygon, or brand logo shape; the light-shielding area is formed on the surface of the embossed light-shielding layer by spraying, printing, or filling processes.

[0009] By adopting the above technical solutions, pixel units are designed as raised or recessed structures with specific geometric shapes such as stars, rhombuses, polygons, or brand logos. Non-transparent, light-blocking areas are formed using spraying, printing, or filling processes. This not only enhances the optical scattering characteristics of the pixel units but also improves brand recognition and design freedom. Customization of the microstructure allows for controllable light emission direction.

[0010] In a preferred embodiment of this application, the LED array is arranged in a rectangular matrix, and the light emission direction of each LED bead coincides with the geometric center axis of the corresponding pixel unit.

[0011] By adopting the above technical solution, the LED array is configured as a rectangular matrix arrangement, and the light emission direction of each LED bead is ensured to coincide with the geometric center axis of its corresponding pixel unit. This achieves high alignment of the light path, effectively reduces crosstalk or misalignment caused by light deviation, and improves the pixel lighting accuracy.

[0012] In a preferred embodiment of this application, the surface of the pixel unit is provided with a frosted layer or is made of a semi-transparent material, so that light is scattered after passing through the pixel unit.

[0013] By employing the above technical solution, a frosted layer or a semi-transparent material is applied to the surface of the pixel unit, allowing the light emitted by the LED to be controllably scattered after passing through the pixel unit, creating a soft and uniform surface light source effect. This design effectively eliminates the glare or uneven brightness caused by point light sources, improving visual comfort.

[0014] Secondly, the objective of this invention is achieved through the following technical solution: A processing method for an invisible pixel display device applied to vehicle exterior trim, applicable to an invisible pixel display device applied to vehicle exterior trim as described above, the method comprising: Identify the design drawing of the display device under test, generate a structural model of the display device under test according to a preset material property table; obtain LED light-emitting layer parameter information, and generate an initial test model based on the structural model and the LED light-emitting layer parameter information; Based on the initial test model, and combining the geometric parameters of the relief light-shielding layer and the optical parameters of the surface paint layer in the structural model, a first simulation test model is generated. Based on the vehicle body surface data corresponding to the target vehicle body type, ambient lighting conditions, and human visual perception model, a second simulation test model containing multi-view observation parameters is constructed. Based on the initial test model, the first simulation test model, and the second simulation test model, a multi-dimensional joint simulation is performed to obtain comprehensive simulation test results.

[0015] By adopting the above technical solution, a complete testing process from structural modeling to multi-dimensional simulation was constructed: first, a structural model was generated based on the design drawings; then, an initial test model was established by combining LED parameters; subsequently, the parameters of the relief shielding layer and the paint layer were integrated to generate the first simulation model; and finally, a second simulation model was constructed by combining the vehicle body surface, lighting, and human visual perception. This three-level progressive simulation system can comprehensively evaluate the optical performance of the device in a real-world environment, significantly shortening the development cycle. The initial test model and the first simulation model use a controlled variable method to control the changes in relevant simulation parameters and device design parameters, thereby achieving comprehensive and refined simulation testing of the display device under test. Different parameters represent the display quality of the device under test, allowing for the determination of whether the display quality obtained from different parameter tests is the same, further improving the judgment of the display quality of the hidden pixel display device. Simultaneously, the second simulation model is combined with human visual perception and simulated display effects in an actual vehicle body to facilitate the judgment of the display quality of the device under test.

[0016] In a preferred embodiment of this application: obtaining LED light-emitting layer parameter information and generating an initial test model based on the structural model and the LED light-emitting layer parameter information includes: Obtain LED light-emitting layer parameter information, which includes light intensity distribution, color coordinates, emission angle, and driving frequency; Based on the LED light-emitting layer parameter information and material property information, the optical performance influence parameters of the hidden pixel display device under test are calculated. The optical performance influence parameters include transparency influence parameters and color reproduction influence parameters. An initial test model is generated based on the optical performance influencing parameters and the structural model.

[0017] By adopting the above technical solution, the generated initial test model can accurately reflect the basic optical behavior of the device; it ensures the authenticity and physical consistency of the simulation input, lays the foundation for evaluating the impact of different material combinations on the display effect, and effectively avoids simulation deviations caused by missing parameters.

[0018] In a preferred embodiment of this application: based on the initial test model, and combining the geometric parameters of the relief light-shielding layer and the optical parameters of the surface paint layer in the structural model, a first simulation test model is generated, including: Extract the microstructure height, pattern period, and duty cycle of the relief light-shielding layer, as well as the local light transmittance distribution of the surface paint layer; The parameters of the relief shading layer and the surface paint layer are coupled into the initial test model to perform optical crosstalk and background blending simulation, thereby generating the first simulation test model.

[0019] By adopting the above technical solution, the simulation of optical crosstalk and background fusion can generate a first simulation test model that can accurately simulate the influence of structural details on the light propagation path in actual manufacturing, so as to predict problems such as light leakage between pixels and background color interference.

[0020] In a preferred embodiment of this application: the second simulation test model, which includes multi-view observation parameters, is constructed based on the vehicle body surface data corresponding to the target vehicle type, ambient lighting conditions, and a human visual perception model, including: The system retrieves a 3D surface model of the target vehicle type from the preset vehicle model database and maps it onto the display device in the specified vehicle body area. Multiple observation points are set up, each corresponding to different human eye viewing distance, viewing angle and environmental illumination conditions; Based on the CIE standard observer function and / or the human eye contrast sensitivity model, a human eye visual response sub-model is constructed and embedded into the first simulation test model to generate the second simulation test model.

[0021] By employing the above technical solution, retrieving the three-dimensional curved surface model of the target vehicle, setting multiple viewing points, and embedding a human eye visual response sub-model based on the CIE standard observer function or contrast sensitivity model, the constructed second simulation test model can realistically reproduce the user's subjective visual experience under different distances, angles, and lighting conditions. This is beneficial for obtaining simulation results that are more closely aligned with actual usage scenarios.

[0022] In a preferred embodiment of this application: the step of performing multi-dimensional joint simulation based on the initial test model, the first simulation test model, and the second simulation test model to obtain comprehensive simulation test results includes: Based on the initial test model and the first simulation test model, an optical performance benchmarking command is triggered. Based on the initial test model and the first simulation test model, as well as the preset optical performance threshold, a simulation test command is triggered to obtain the initial test result and the first simulation test result, respectively. The optical performance threshold includes the minimum visible brightness threshold, the maximum background fusion error tolerance, or the color shift tolerance. Based on the initial test results and the first simulation test results, an optical performance difference report is generated, and the simulation model that meets the optical performance threshold is used as a benchmark input to the second simulation test model. In the second simulation test model, multi-view observation simulations are run under daytime high illumination, nighttime low illumination, and twilight transition scenarios, respectively, and the visibility index of the hidden pixels, background fusion error value, and color consistency score of each observation point are output. If the visibility index is lower than the preset threshold or the background fusion error value exceeds the allowable range under any observation condition, the structured optics feedback command is triggered to dynamically adjust the pattern distribution density of the relief light-shielding layer, the local transmittance gradient of the surface paint layer, or the driving brightness and lighting sequence of the LED light-emitting layer, and the initial test model is regenerated with the updated parameters. The simulation process is iteratively executed until the human visual consistency requirements are met under all target vehicle types and observation conditions.

[0023] By adopting the above technical solution, and benchmarking the optical performance of the initial model against the first simulation model, and combining preset visible brightness, fusion error, and color shift tolerance thresholds for multi-scenario verification, this method achieves closed-loop feedback from basic performance evaluation to real-world environmental adaptability. When the simulation results fail to meet the standards, the system automatically triggers dynamic adjustments to the relief structure, paint transmittance, or LED driving strategy, and iteratively updates the model. This improves product development efficiency and final display quality.

[0024] In a preferred embodiment of this application: the step of identifying the design drawing of the display device under test and generating a structural model of the display device under test based on a preset material property table specifically includes: Identify the design drawings of the display device under test, extract the pigment composition and film thickness of the surface paint layer, the microstructure morphology data of the relief light-shielding layer, and the pixel arrangement and packaging form of the LED light-emitting layer; Based on the extracted data and a preset material property table, a multilayer optical structure model including interlayer interface reflectivity, scattering coefficient, and absorption coefficient is established as the structure model.

[0025] By adopting the above technical solution and combining it with the material property table to construct a multi-layer optical structure model that includes interface reflectivity, scattering coefficient and absorption coefficient, the generated structure model has high physical fidelity and can accurately describe the propagation, reflection and attenuation behavior of light between layers.

[0026] In summary, this application includes the following beneficial technical effects: 1. This application achieves the dual goals of "completely invisible in the off state" and "high-contrast display in the illuminated state" for the vehicle exterior display device by sequentially stacking a surface paint layer, an embossed light-shielding layer, and an LED light-emitting layer, and introducing a control unit to drive the LED array to light up according to a preset pattern. The uniform paint layer ensures that the appearance is consistent with the original paint when not illuminated; the embossed light-shielding layer precisely defines the light-transmitting area and effectively suppresses stray light leakage; the LED array corresponds one-to-one with the pixel unit to ensure image reproduction accuracy; the control unit supports dynamic pattern switching and expands intelligent interactive functions. 2. A complete testing process from structural modeling to multi-dimensional simulation has been established. In actual production applications, it is not only suitable for high-precision personalized customization, but also improves the accuracy of judging the display quality of hidden pixel display devices. Attached Figure Description

[0027] Figure 1 This is an overall schematic diagram of a hidden pixel display device applied to the exterior of a vehicle body, comprising a surface paint layer, an embossed light-shielding layer, and an LED light-emitting layer stacked sequentially in one embodiment of this application. Figure 2 This is a structural diagram of the surface paint layer, the embossed light-shielding layer, and the LED light-emitting layer in an invisible pixel display device applied to the exterior of a vehicle body, according to an embodiment of this application. Figure 3 This is a flowchart of a processing method for an invisible pixel display device applied to the exterior of a vehicle body, according to an embodiment of this application.

[0028] Explanation of reference numerals in the attached figures: 1. Surface paint layer; 2. Embossed light-shielding layer; 21. Pixel unit; 3. LED light-emitting layer. Detailed Implementation

[0029] The present application will be further described in detail below with reference to the accompanying drawings.

[0030] In one embodiment, such as Figure 1 and Figure 2 As shown, this application discloses an invisible pixel display device for vehicle exterior trim. The invisible pixel display device includes a surface paint layer 1, an embossed light-shielding layer 2, and an LED light-emitting layer 3 stacked sequentially. The LED light-emitting layer 3 is electrically connected to a control unit. The surface paint layer 1 is a transparent or semi-transparent substrate, and a uniform paint layer is provided on the side facing the observer. For example, a transparent polymethyl methacrylate (PMMA, commonly known as acrylic) sheet with a thickness of 2.0 mm is selected as the substrate of the surface paint layer 1. The customer-specified vehicle body paint (such as white pearlescent paint) is sprayed onto the outer surface of the surface paint layer 1, and after drying and curing, it is bonded to the embossed light-shielding layer 2 by hot pressing or UV adhesive.

[0031] The embossed light-shielding layer 2 includes a pixel unit array and a light-shielding area. The pixel unit array is a microstructure array arranged horizontally and vertically. Each pixel unit 21 in the pixel unit array is a raised or recessed structure, and its shape includes star, rhombus, polygon, or brand logo shape. This embodiment uses a rectangle as an example. The surface of the pixel unit 21 is provided with a frosted layer or a semi-transparent material, so that the light is scattered after passing through the pixel unit 21. For example, the frosted layer forms random micro-pits with Ra=1.2μm on the surface of the pixel unit 21 by laser etching or chemical etching; or when the embossed light-shielding layer 2 is injection molded, silica scattering particles with a particle size of 5μm are added to the PC substrate at a volume fraction of 3%, so that the light emission angle is broadened to ±40°.

[0032] The light-shielding area covers the area outside the pixel unit array; the light-shielding area is formed on the surface of the relief light-shielding layer 2 through spraying, printing, or filling processes. For example, an acrylic sheet of the same material is prepared as the substrate of the relief light-shielding layer 2, and a circular micro-protrusion array (diameter 1.5mm, height 0.3mm, spacing 2.0mm) arranged horizontally and vertically is processed on one side of it by a CNC engraving machine to form a pixel unit array. The LED light-emitting layer 3 includes a PCB substrate and an LED array located on the PCB substrate. The LED array contains multiple RGB full-color LED beads with a spacing of 2.0mm and arranged in a rectangular shape; for example, the LED light-emitting layer 3 uses a rigid FR-4 PCB board. The positions of the LED array and the pixel unit array correspond one-to-one; in this embodiment, the LED array is arranged in a rectangular matrix, and the light emission direction of each LED bead coincides with the geometric center axis of the corresponding pixel unit 21.

[0033] The control unit receives image signals and drives specific LEDs in the LED array to light up according to a preset pattern. The control unit is integrated on a PCB circuit board (not shown in the figure) and includes an STM32 series MCU and a Bluetooth communication module. The control unit uses a microcontroller module with an automotive CAN bus interface and pre-stores image data such as the brand logo and welcome animation. Specifically, the control unit generates bitmap instructions based on the pre-stored image data, converting the RGB value of each pixel into the corresponding LED's PWM duty cycle. For example, for a 20×10 pixel logo, the control unit's MCU activates each row of LEDs sequentially in a line-scanning manner and completes the entire frame refresh within 1ms.

[0034] In another embodiment, such as Figure 3 As shown, this application also discloses a processing method for an invisible pixel display device applied to vehicle exterior trim. This processing method for an invisible pixel display device applied to vehicle exterior trim specifically includes the following steps: S1: Identify the design drawing of the display device under test, and generate a structural model of the display device under test based on the preset material property table.

[0035] In this embodiment, a multi-level simulation model is constructed, from the basic structure to the real-world application scenario, thereby achieving high-precision prediction without relying on a physical prototype and improving the accuracy of judging the display quality of the hidden pixel display device. This embodiment provides a processing method for a hidden pixel display device applied to vehicle exterior trim. The design drawings include the structure, material parameters, and key parameters of each functional layer of the hidden pixel display device under test; the preset material property table is a database containing the optical properties of common automotive materials, such as the transmittance of different paint colors, the refractive index of acrylic, the complex refractive index of each material in the wavelength range of 380–780 nm, the volume scattering coefficient, the absorption coefficient of black ink, and bidirectional reflectance distribution function (BRDF) data, etc.

[0036] Specifically, step S1 includes: S11: Identify the design drawing of the display device under test, extract the pigment composition and film thickness of the surface paint layer, the microstructure morphology data of the relief light-shielding layer, and the pixel arrangement and packaging form of the LED light-emitting layer.

[0037] In this embodiment, the design drawings include various formats such as 3D CAD assembly models, 2D engineering drawings, PCB Gerber files, and process specification documents. The pigment composition of the surface paint layer is used to match its spectral absorption characteristics, and the film thickness affects the light transmittance and phase delay; the microstructure morphology data of the embossed light-shielding layer determines the pixel edge sharpness and light scattering behavior, including the geometric parameters of individual pixel units and the spatial arrangement parameters of the pixel array; the pixel arrangement and packaging form of the LED light-emitting layer are related to the accuracy of the light source position and the distribution of the light emission angle.

[0038] S12: Based on the extracted data and the preset material property table, establish a multilayer optical structure model that includes the interlayer interface reflectivity, scattering coefficient and absorption coefficient, as the structural model.

[0039] In this embodiment, the multilayer optical structure model is a physical model constructed in a professional optical simulation platform that can accurately simulate the entire process of light reflection, transmission, scattering and absorption at the interlayer interface.

[0040] For example, in a front bumper hidden logo project for a certain car model, the design drawing is first loaded, and three-layer component entities are separated from it. By associating with the Bill of Materials (BOM) in the PLM system, the surface paint layer is identified as using "Midnight Black Metallic" paint, whose pigment composition is an aluminum powder + carbon black composite system, and the standard construction film thickness is 35μm. The CAD feature tree of the embossed light-shielding layer contains an array feature named "Pixel_Array_V2". Its geometric attributes are analyzed: each pixel unit is a circular boss with a diameter of 1.5mm, a height of 0.3mm, a center-to-center spacing of 2.0mm, and arranged in 20 rows × 10 columns; non-pixel areas are marked as "light-shielding areas". The PCB design of the LED light-emitting layer is provided in Gerber format. After analysis, it is found that it uses RGB LEDs in 0603 packages, arranged in the same 20×10 matrix, with the center coordinates of the pads strictly aligned with the center of the embossed pixel, and the package lens is a hemispherical silicone.

[0041] Then, the "Midnight Black Metallic" paint name extracted from S11 was matched to the material property table, and its typical parameters at a wavelength of 550nm were retrieved: absorption coefficient α = 1100nm. -1 Scattering coefficient σ_s=280m -1 The anisotropy factor g = 0.82; the refractive index n = 1.585 and the extinction coefficient k ≈ 0 of the transparent PC substrate (embossed layer material); the light-shielding area is endowed with α = 4800 μm due to the filling of black epoxy resin. -1 The σ_s of the LED encapsulation silicone is 750m. -1 Subsequently, in the Ansys SPEOS simulation environment, the system automatically created a three-layer dielectric structure: the first layer was a 35μm thick paint layer, using the Henyey-Greenstein volume scattering model; the second layer was an embossed structure, with transparent areas using PC material properties and light-shielding areas using a high-absorption material; the third layer was a point light source array, with its position and orientation driven by PCB data. Dynamic reflectivity calculations based on the Fresnel formula were used at each layer interface, taking into account scattering caused by roughness; thus, the structural model was obtained.

[0042] S2: Obtain LED light-emitting layer parameter information, and generate an initial test model based on the structural model and LED light-emitting layer parameter information.

[0043] In this embodiment, the LED light-emitting layer parameter information refers to the photometric and colorimetric data provided by the LED supplier, which is used to define the characteristics of the light source; the initial test model is a basic optical simulation model based on the structural model with an idealized light source added, which is used to initially evaluate the light output capability.

[0044] Specifically, step S2 includes: S21: Obtain LED light-emitting layer parameter information, including light intensity distribution, color coordinates, light emission angle and driving frequency.

[0045] In this embodiment, the light intensity distribution is measured by using an integrating sphere or a spectroradiometer to measure the relative light intensity distribution of the LED at different viewing angles, obtaining its IV curve and spatial angular light intensity distribution map. The color coordinates are determined using a spectrophotometer to measure the CIE 1931 xy color coordinate values ​​of the LED under standard light source conditions. The emission angle is determined based on the manufacturer's specifications or actual measurement results to determine the LED's half-power angle (i.e., the angle range at which the brightness drops to half its peak value) to analyze the effective area covered by the light. The driving frequency is used to record and confirm the PWM modulation frequency or other forms of driving frequency used when the LED is operating.

[0046] S22: Based on the LED light-emitting layer parameter information and material property information, calculate the optical performance influence parameters of the hidden pixel display device under test. The optical performance influence parameters include transparency influence parameters and color reproduction influence parameters.

[0047] In this embodiment, material properties such as absorption coefficient and scattering coefficient are considered. Transparency parameters take into account the influence of each layer of medium on light transmittance, particularly the effects of the surface paint layer and the embossed light-blocking layer. Rayleigh scattering theory combined with Mie scattering theory can be used to estimate the scattering loss during light transmission. Color reproduction parameters can be evaluated based on the CIEDE2000 color difference formula, assessing the degree of color shift caused by the combined effects of material absorption and LED emission characteristics; that is, by calculating the weighted distance between the target color and the actual displayed color in the CIELAB color space.

[0048] For example, the light intensity distribution of the RGB LED beads obtained through testing approximates a Lambertian mode. The dominant wavelengths are 625nm, 528nm, and 470nm, corresponding to color coordinates of (0.70, 0.29), (0.21, 0.71), and (0.14, 0.07), respectively. The emission angle is approximately 120 degrees, and the driving frequency is set to 2kHz. Assuming the refractive index of the transparent PC substrate is 1.585 with no significant absorption, while the surface paint layer has a certain degree of absorption, the transmittance variation trend under different viewing angles can be obtained through software simulation. For color reproduction, the above color coordinate data is combined with the absorption spectrum of each layer of material for calculation to quantify color deviation.

[0049] S23: Generate an initial test model based on the optical performance influencing parameters and structural model.

[0050] In this embodiment, all the optical performance influencing parameters calculated previously are incorporated into the established structural model to form a complete initial test model.

[0051] Specifically, a structural model containing all physical properties is imported into professional optical simulation software (such as Ansys SPEOS), and corresponding optical performance influence parameters are set. These parameters are then adjusted for different test scenarios to facilitate optical simulation analysis of the hidden pixel display device.

[0052] S3: Based on the initial test model, the first simulation test model is generated by combining the geometric parameters of the relief shading layer and the optical parameters of the surface paint layer in the structural model.

[0053] In this embodiment, the geometric parameters of the relief light-shielding layer include microscopic features such as the height, shape, and period of the pixel unit; the optical parameters of the surface paint layer mainly refer to the local transmittance and scattering characteristics; the first simulation test model, by coupling these parameters, more realistically simulates the propagation behavior of light in the multi-layer structure.

[0054] Specifically, step S3 includes: S31: Extract the microstructure height, pattern period, and duty cycle of the relief shading layer, as well as the local light transmittance distribution of the surface paint layer.

[0055] In this embodiment, the first simulation test model aims to verify the invisible pixel display device in a virtual environment that closely resembles a real-world usage scenario. Microstructure height refers to the vertical protrusion or depression depth of a pixel unit relative to the light-blocking area; pattern period is the distance between the centers of adjacent pixels; duty cycle is defined as the ratio of the area of ​​a single pixel unit to the total area of ​​a single periodic unit, reflecting the proportion of the light-transmitting area; local transmittance distribution describes the ability of the surface paint layer to transmit visible light at different locations, which may vary spatially due to coating uniformity or film thickness fluctuations. The local transmittance distribution is obtained by scanning the paint layer with a microspectrophotometer after coating, with a step size of 0.1 mm, generating a two-dimensional transmittance matrix T(x, y) at a wavelength of 550 nm, which is then imported into the simulation model as a material property.

[0056] S32: Couple the parameters of the relief shading layer and the surface paint layer into the initial test model, perform optical crosstalk and background blending simulation, and generate the first simulation test model.

[0057] In this embodiment, parameter coupling refers to injecting the geometric and optical parameters extracted in step S31 as boundary conditions or material properties into the established initial test model, replacing the original idealized assumptions such as "completely transparent pixels" and "uniform transmittance," thereby improving the physical realism of the model. Optical crosstalk simulation is used to evaluate whether the light from a pixel leaks into neighboring pixel areas when a pixel is lit, causing pattern blurring; background blending simulation calculates the brightness / color difference between the device area and the surrounding vehicle body paint surface in the unlit state to determine whether it is "invisible."

[0058] Specifically, in the initial test model, the embossed light-shielding layer was first replaced with a periodic microstructure mesh with a height of 0.28 mm and a duty cycle of 47%, and the non-pixel areas were given an absorption coefficient α = 4500 μm. -1 (Simulate a high-shield black coating); secondly, set the surface paint layer as a non-uniform medium, and assign its transmittance point by point according to the two-dimensional distribution map generated by S31; finally, enable the Monte Carlo ray tracing engine and emit 100 million rays to simulate the RGB LED lighting state.

[0059] Simulation results show that the crosstalk between adjacent pixels is less than 3% (meeting the design requirement of <5%); in the off state, the average brightness of the device area is 98 cd / m². 2 With the surrounding paint (100cd / m) 2 The Michelson contrast ratio of the sample was only 0.01, far below the human visual threshold (0.1), thus classifying it as "visually invisible." This result, along with the light intensity distribution map and crosstalk thermal analysis... Figure 1 This is then saved to form a complete first simulation test model, which will be used for subsequent multi-view environment simulation input.

[0060] S4: Based on the vehicle body surface data corresponding to the target vehicle body type, ambient lighting conditions, and human visual perception model, a second simulation test model containing multi-view observation parameters is constructed.

[0061] In this embodiment, the target vehicle type refers to a specific vehicle model, such as an SUV of a certain brand; the vehicle body surface data is a high-precision Class-A surface, used to accurately reproduce the geometry of the device installation area; the ambient lighting conditions cover typical daytime, nighttime, and transitional lighting scenarios; the human eye visual perception model is used to convert physical light measurements into subjective visual responses; the second simulation test model places the device in a real usage environment for verification and visual feedback testing; and effectively predicts the multi-view display performance of the hidden pixel display device in actual road environments.

[0062] Specifically, step S4 includes: S41: Retrieve the 3D surface model of the target vehicle type from the preset vehicle model database and map it onto the specified vehicle body area on the display device.

[0063] In this embodiment, the preset vehicle model database is a CAE-verified 3D digital model library of the whole vehicle stored in the enterprise's Product Lifecycle Management (PLM) system, containing complete exterior A-level curved surface data for each vehicle model. The mapping display device refers to accurately positioning the aforementioned multi-layer optical structure model to a designated area of ​​the vehicle body (such as the center of the front bumper, the logo position on the rear wing, etc.) according to the engineering assembly relationship, ensuring that its normal and curvature are consistent with the actual installation state.

[0064] S42: Set multiple observation points, each corresponding to different human eye viewing distance, viewing angle and environmental illumination conditions.

[0065] In this embodiment, the observation points are a set of virtual camera locations that simulate the positions of real users or third-party observers, and their settings need to cover typical usage scenarios. The human eye viewing distance refers to the distance between the observer and the display area, such as 3m for a pedestrian, 10m for a driver, and 1m for after-sales inspection. The viewing angle includes the horizontal tilt angle and the pitch angle; ambient illumination conditions represent the background light intensity under different times and weather conditions.

[0066] For example, 12 observation points were set up around the vehicle model: 4 in front of the vehicle to simulate a welcoming scene; 4 on the sides to simulate pedestrians passing by; and 4 behind to simulate following vehicles. Each point had a defined set of parameters. For example, point P1, 3m directly in front, with a horizontal angle of 0°, a pitch angle of +10°, and an illuminance of 100,000 lux, was used to simulate the perspective of a pedestrian under midday sunlight; point P5, 5m to the left, with a horizontal angle of -45°, a pitch angle of 0°, and an illuminance of 5,000 lux, was used to simulate the perspective of a roadside at dusk; and point P9, 8m behind, with a horizontal angle of 0°, a pitch angle of -5°, and an illuminance of 10 lux, was used to simulate the perspective of following vehicles at night. The ambient light sources at all points were loaded with realistic skyboxes using HDRI (High Dynamic Range Imaging) technology, including direct sunlight, diffused skylight, and ground reflections, to improve the physical realism of the lighting during the simulation.

[0067] S43: Based on the CIE standard observer function and / or the human eye contrast sensitivity model, construct a human eye visual response sub-model and embed it into the first simulation test model to generate the second simulation test model.

[0068] In this embodiment, the CIE standard observer function is used to convert the simulated spectral radiance data into CIEXYZ chromaticity values, and then calculate color difference and luminance. The human eye contrast sensitivity model (such as CSF) is used to evaluate the human eye's ability to resolve patterns at specific spatial frequencies, particularly suitable for determining whether low-contrast patterns are perceptible. The human eye visual response sub-model is a pluggable perception evaluation module embedded at the end of the optical simulation process, converting physical results into subjective scores.

[0069] Specifically, to construct the human visual response sub-model, the "Human Vision" plugin was first enabled on the simulation platform, and the CIE 1931 2° standard observer function was configured as the chromaticity transformation core to convert the spectral radiance data (unit: W·sr) output by ray tracing. -1 ·m -2 ·nm -1 The values ​​were converted to CIE XYZ tristimulus values, and the luminance Y (unit: cd / m²) was further calculated. 2 The model uses CIELAB color coordinates and a Barten contrast sensitivity model. It sets parameters such as viewing distance, pupil diameter (e.g., 4mm), and ambient brightness to calculate the minimum contrast threshold that the human eye can distinguish under the current viewing conditions. After the first simulation test model completes ray tracing, its output illuminance and chromaticity maps are fed into the Barten contrast sensitivity model: first, the Michelson contrast ratio C = (L...) between the display area and the background area is calculated. max -L min ) / (L max +L min (where L) max L min These are the brightness values ​​of the brightest part and the darkest part within the same observation area, respectively; then, the contrast ratio is determined based on the CSF curve to determine whether it exceeds the human eye's perception threshold; simultaneously, the CIEDE2000 color difference value is output to assess color fidelity.

[0070] Finally, the visibility scores (0–5 points), contrast values, and color difference values ​​of all observation points are integrated into a comprehensive report and output together with the rendered images to form a complete second simulation test model.

[0071] For example, the Barten model calculates the human eye's contrast sensitivity S(f) (i.e., the reciprocal of the contrast threshold) using the following core formula: Where k is the neural noise factor, which is recommended to be 3.0 according to Barten (1999) Human Contrast Sensitivity; φ is the radians, which is related to the observation distance; X0 is the target size factor, which can be set to 1.0; and f is the spatial frequency, which is determined by the physical size of the hidden pixel and the observation distance d. D is the observation distance, and d is the pupil diameter. At an observation point 3.0m away, d = 1.5mm, D = 3000mm, so f ≈ 2 cycles / degree. f0 is the theoretically highest resolvable frequency determined by the human eye's optical system (mainly pupil diffraction and aberrations), and is related to the aperture diameter; a typical value is 20 cycles / degree. max This is the neural cutoff frequency, typically around 60 cycles / degree; f c This refers to the peak frequency of contrast sensitivity at medium brightness (e.g., 100 cd / m²). 2 ), approximately 3–5 cycles / degree; b is the high-frequency attenuation slope parameter, approximately 0.3–0.5.

[0072] The human eye perception threshold refers to the minimum Michelson contrast value required for the human eye to just perceive a spatial frequency pattern under specific environmental illumination, viewing distance, viewing angle, and background brightness. If the actual pattern contrast is lower than this threshold, the human eye cannot recognize it and considers it "invisible." The human eye perception threshold is the reciprocal of contrast sensitivity. Based on CIE LAB color coordinates, the CIEDE2000 color difference value ΔE_0 is calculated. When ΔE_0 is greater than 3, color distortion is considered significant.

[0073] S5: Based on the initial test model, the first simulation test model, and the second simulation test model, perform multi-dimensional joint simulation to obtain comprehensive simulation test results.

[0074] In this embodiment, the initial test model represents a basic optical model considering only the LED light source and ideal structure; the first simulation test model is a high-fidelity model incorporating the geometric details of the relief shading layer and the optical non-uniformity of the surface paint layer; the second simulation test model further integrates the real vehicle body surface, ambient lighting, and human visual perception mechanisms to simulate actual road observation conditions. Multi-dimensional joint simulation refers to comparing the outputs of different models horizontally and evaluating the performance in multiple scenarios vertically; the comprehensive simulation test results are presented as test conclusions in the form of quantitative indicators, the feasibility of the design is judged through quantitative indicators, and automatic optimization is triggered when the standards are not met.

[0075] Specifically, step S5 includes: S51: Based on the initial test model and the first simulation test model, trigger the optical performance benchmarking command.

[0076] In this embodiment, optical performance benchmarking refers to comparing the output results of the initial test model of the idealized model with those of the refined model (the first simulation test model) under the same input conditions to identify performance deviations caused by structural details such as relief height and paint absorption. The benchmarking command is automatically triggered by the simulation platform to initiate the difference analysis process.

[0077] For example, in Ansys SPEOS, an initial test model (assuming completely transparent pixels and uniform 8% transmittance of the paint) and a first simulation test model (including 0.3mm embossed bosses, 47% duty cycle, and non-uniform transmittance distribution) are loaded in parallel. After running ray tracing, the center pixel brightness of both models under the same LED driving conditions is extracted: the initial model outputs 150 cd / m². 2 The first simulation model outputs 118 cd / m³. 2 The deviation reached 21.3%. An automatic benchmarking report was generated, which indicated that the main sources of loss were "paint layer absorption (-12%)" and "relief edge diffraction (-9%)".

[0078] S52: Based on the initial test model and the first simulation test model, as well as the preset optical performance thresholds, trigger the simulation test command to obtain the initial test results and the first simulation test results respectively. The optical performance thresholds include the minimum visible brightness threshold, the maximum background fusion error tolerance, or the color shift tolerance.

[0079] In this embodiment, the preset optical performance threshold is an acceptance boundary set based on human visual experiments and brand visual standards. For example, the minimum visible brightness threshold is set to 80 cd / m². 2 The maximum background fusion error tolerance is defined as a brightness difference of ≤5 cd / m² between the device area and the vehicle background when the device is off. 2 The "color offset tolerance" uses CIEDE2000 color difference ΔE_0≤3. The simulation test command automatically runs the model and outputs the result of whether it meets the standard.

[0080] For example, a test was performed on the first simulation test model: the center brightness was 118 cd / m² when lit. 2 >80cd / m 2 The test showed that the average brightness in the off state was 97 cd / m². 2 Vehicle body background 100cd / m 2 The error (RMSE) is 2.3 cd / m. 2 <5cd / m 2 The test was passed; when RGB lighting was enabled, ΔE_0 = 2.4 < 3, also passing the test. Therefore, the model was determined to "meet the basic optical performance threshold" and is allowed to proceed to the next stage of verification.

[0081] S53: Based on the initial test results and the first simulation test results, generate an optical performance difference report, and input the simulation model that meets the optical performance threshold as a benchmark into the second simulation test model.

[0082] In this embodiment, the second simulation test result refers to the multi-view evaluation result processed by the human eye vision model. The second simulation test model is a high-order simulation environment specifically designed for dynamic verification under full operating conditions, integrating time, illumination, and viewing angle variables. The optical performance difference report is used to record the performance evolution path between models and to identify the physical causes of performance degradation, such as material absorption and geometric occlusion.

[0083] Specifically, the first simulation test model (which has passed step S52) is used as the optical kernel and mapped onto the A-level curved surface of the front bumper of the target vehicle, with 12 observation points configured (covering pedestrian, driver, and after-sales perspectives). A difference report is archived simultaneously to trace the impact of design changes. At this point, the second simulation test model has complete physical-sensory coupling capabilities and can perform dynamic scene simulations.

[0084] S54: In the second simulation test model, run multi-view observation simulations under daytime high illumination, nighttime low illumination and twilight transition scenarios respectively, and output the visibility index of hidden pixels, background fusion error value and color consistency score of each observation point.

[0085] In this embodiment, the visibility index is rated on a scale of 0–5, where 0 is completely invisible; 3 is just noticeable; and 5 is very clear and unblurred. The visibility score is calculated as: (human eye perception threshold in the Barten contrast sensitivity model) / (actual Michelson contrast in the Michelson contrast model). Actual Michelson contrast = (brightness of the illuminated pixel area - brightness of the surrounding vehicle background) / (brightness of the illuminated pixel area + brightness of the surrounding vehicle background). The background blending error value refers to the brightness difference between the device and the vehicle body at various viewing angles when the device is off. The color consistency score is based on the standard deviation of ΔE_0 over multiple viewing angles; a lower value indicates more stable color.

[0086] For example, the simulation results are as follows: Nighttime (10 lux): Visibility score of all locations ≥ 4.2, background blending error ≤ 2.0 cd / m 2 Color consistency score: 0.7; Dusk (5,000 lux): Visibility score: 3.5–4.0, blending error ≤3.0 cd / m 2 Consistency score: 1.1; Daytime (100,000 lux): Visibility score at a point 3m directly in front is only 2.5 (<3.0 threshold), while other points are acceptable; background blending is still good (error 1.8 cd / m). 2 However, strong ambient light resulted in insufficient pattern contrast.

[0087] Therefore, marking "Visibility is not up to standard in high-light daytime scenes" triggers the optimization process.

[0088] S55: If the visibility index is lower than the preset threshold or the background fusion error exceeds the allowable range under any observation condition, the structured optics feedback command is triggered to dynamically adjust the pattern distribution density of the relief shading layer, the local transmittance gradient of the surface paint layer, or the driving brightness and lighting sequence of the LED light-emitting layer. The initial test model is then regenerated with the updated parameters, and the simulation process is iteratively executed until the visual consistency requirements of the human eye are met under all target vehicle types and observation conditions.

[0089] In this embodiment, the preset threshold is 3.0, and the background fusion error value is represented by the background brightness difference, such as ≤2.0 cd / m² in the darkest night scene. 2 ≤3.0 cd / m³ in twilight scenes 2 ≤1.8cd / m² in high-illuminance daytime scenarios 2 The iteration termination condition is: under all target vehicle types, all 12 observation points, and three lighting scenarios, the visibility score is ≥3.0 and the background fusion error is ≤5cd / m. 2 Both ΔE_0 ≤ 3.0 and the condition are true simultaneously. Structured optics feedback instructions are an intelligent recommendation mechanism based on the physical mechanisms of failed scenarios. For example, insufficient daytime visibility is mainly due to low brightness contrast, so prioritizing increasing light source output is crucial; if background blending fails, then optimizing light-blocking or paint design is necessary. As mentioned above, pixel units can use semi-transparent materials or frosted finishes to enhance scattering.

[0090] For example, three adjustments are recommended: LED light-emitting layer: Enable ambient light adaptive driving strategy - when the ambient illuminance is >10,000 lux, the driving current is dynamically increased from 20mA to 26mA, and 1kHz PWM dimming (duty cycle 85%) is used to prevent overheating; Embossed light-shielding layer: Maintains the existing height, but increases the pixel duty cycle from 45% to 52%, increasing the effective light-emitting area; Surface paint layer: Combined with the surface of the pixel unit having a frosted treatment layer or a semi-transparent material limit, the local light transmittance gradient in the corresponding area of ​​the pixel is finely adjusted, so that the center light transmittance is increased from 8.2% to 9.0%, while keeping the edges unchanged to maintain the overall appearance consistency.

[0091] The updated parameters are written to the design database, automatically triggering a full resimulation from steps S1 to S5. This continues until all 12 points meet the threshold requirements under all three lighting scenarios. The system then terminates the iteration.

[0092] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0093] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of a processing method for an invisible pixel display device applied to a vehicle body exterior.

[0094] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0095] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0096] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A stealth pixel display device applied to an exterior of a vehicle body, characterized by, The display device comprises a surface color paint layer (1), a relief shading layer (2) and an LED light-emitting layer (3) arranged in sequence, and the LED light-emitting layer (3) is electrically connected with a control unit; The surface color paint layer (1) is a transparent or translucent substrate, and the side facing the observer is provided with a uniform color paint layer; the relief shading layer (2) comprises a pixel unit array and a shading area, the pixel unit array is an array of microstructures arranged in horizontal and vertical directions, and the shading area covers the area outside the pixel unit array; the LED light-emitting layer (3) comprises a PCB substrate and an LED array on the PCB substrate, and the LED array corresponds to the pixel unit array one by one in position; The control unit is used for receiving an image signal and driving specific LEDs in the LED array to light up in a preset pattern.

2. The invisible pixel display device for application to the exterior of a vehicle body according to claim 1, characterized by, Each pixel unit (21) in the pixel unit array is a convex or concave structure, and the shape includes star, diamond, polygon or brand logo shape; the shading area is formed on the surface of the relief shading layer (2) by spraying, printing or filling process.

3. The invisible pixel display device for application to the exterior of a vehicle body according to claim 1, characterized by, The LED array is arranged in a rectangular matrix, and the light-emitting direction of each LED lamp bead coincides with the geometric center axis of the corresponding pixel unit (21).

4. The invisible pixel display device for application to the exterior of a vehicle body according to claim 1, characterized by, The surface of the pixel unit (21) is provided with an frosting treatment layer or adopts a translucent material, so that the light is scattered and distributed after passing through the pixel unit (21).

5. A processing method of a stealth pixel display device applied to an exterior of a vehicle body, characterized by, The method is applied to the invisible pixel display device applied to the body outer decoration of any one of claims 1-4, and the method comprises: Identifying a design drawing of a to-be-tested display device, generating a structure model of the to-be-tested display device according to a preset material attribute table; Obtaining LED light-emitting layer parameter information, and generating an initial test model according to the structure model and the LED light-emitting layer parameter information; Based on the initial test model, combining the geometric parameters of the relief shading layer and the optical parameters of the surface color paint layer in the structure model, a first simulation test model is generated; Based on the target vehicle body type corresponding to the vehicle body surface data, the environmental light condition and the human eye visual perception model, a second simulation test model containing multi-view observation parameters is constructed; Based on the initial test model, the first simulation test model and the second simulation test model, multi-dimensional joint simulation is performed to obtain a comprehensive simulation test result.

6. The processing method of the invisible pixel display device applied to the exterior of a vehicle body according to claim 5, characterized in that, The obtaining of the LED light-emitting layer parameter information, the generation of the initial test model according to the structure model and the LED light-emitting layer parameter information comprises: Obtaining LED light-emitting layer parameter information, the LED light-emitting layer parameter information including light intensity distribution, color coordinates, light-emitting angle and driving frequency; According to the LED light-emitting layer parameter information and the material attribute information, the optical performance influence parameters of the to-be-tested invisible pixel display device are calculated, the optical performance influence parameters including transparency influence parameters and color restoration influence parameters; According to the optical performance influence parameters and the structure model, an initial test model is generated.

7. The processing method of the invisible pixel display device applied to the exterior of a vehicle body according to claim 5, characterized in that, The generation of the first simulation test model based on the initial test model, combining the geometric parameters of the relief shading layer and the optical parameters of the surface color paint layer in the structure model comprises: extracting microstructure height, pattern period and duty cycle of the relief light shielding layer, and local light transmittance distribution of the surface color paint layer; coupling parameters of the relief light shielding layer and the surface color paint layer into the initial test model to simulate optical crosstalk and background fusion degree, and generating a first simulation test model.

8. The processing method of the invisible pixel display device applied to the exterior of a vehicle body according to claim 5, characterized in that, Based on the vehicle body type corresponding to the body surface data, the ambient light condition and the human eye visual perception model, a second simulation test model containing multi-view observation parameters is constructed, including: From the preset vehicle model database, the three-dimensional surface model of the target vehicle body type is called, and the display device is mapped to the specified body area; Set multiple observation points, each observation point corresponds to different eye distance, angle and ambient illumination condition; Based on the CIE standard observer function and / or human eye contrast sensitivity model, a human eye visual response sub-model is constructed and embedded into the first simulation test model to generate a second simulation test model.

9. The processing method of the invisible pixel display device applied to the exterior of a vehicle body according to claim 5, characterized in that, Based on the initial test model, the first simulation test model and the second simulation test model, multi-dimensional joint simulation is performed to obtain comprehensive simulation test results, including: Based on the initial test model and the first simulation test model, trigger optical performance benchmarking instructions; Based on the initial test model and the first simulation test model, and the preset optical performance threshold, trigger simulation test instructions to obtain initial test results and first simulation test results respectively, the optical performance threshold includes minimum visible brightness threshold, maximum background fusion error tolerance or color offset tolerance; According to the initial test results and the first simulation test results, generate an optical performance difference report, and input the simulation model meeting the optical performance threshold into the second simulation test model as a reference; In the second simulation test model, multi-view observation simulation under the conditions of high illumination in the daytime, low illumination at night and dusk transition is respectively run, and the visibility index, background fusion error value and color consistency score of the stealth pixel under each observation point are outputted; If the visibility index under any observation condition is lower than the preset threshold or the background fusion error value exceeds the allowable range, trigger the structure optical feedback instruction, dynamically adjust the pattern distribution density of the relief light shielding layer, the local light transmittance gradient of the surface color paint layer, or the driving brightness and timing sequence of the LED light-emitting layer, and regenerate the initial test model with updated parameters to iterate the simulation process until the human eye visual consistency requirements are met under all target vehicle body types and observation conditions.

10. The processing method of the invisible pixel display device applied to the exterior of a vehicle body according to claim 5, characterized in that, The design drawing of the display device to be tested is identified, and the structure model of the display device to be tested is generated according to the preset material attribute table, specifically including: Identify the design drawing of the display device to be tested, extract the pigment composition and film thickness of the surface color paint layer, the microstructure morphology data of the relief light shielding layer, and the pixel arrangement and packaging form of the LED light-emitting layer; According to the extracted data and the preset material attribute table, a multi-layer optical structure model containing interfacial reflectivity, scattering coefficient and absorption coefficient is established as the structure model.

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